First Dabblings

In 1998 my family returned to Sunnyvale from a year in Spain, where all three of us focused on learning the language, experiencing a different lifestyle, and hanging out. We disposed of a lot of things when we left for the year. On returning part of our reintroduction into our California life was obtaining a new car. That was our first electric vehicle, a 1998 Honda EVPlus. (You can see them being crushed in the film Who Killed the Electric Car?)

The experience with that car left us with the conviction that whenever another mass produced EV was available, we would be buying it. Other than few months leasing from Hertz a Ford iThink, it took 7 years after losing our Honda to buy our first Nissan Leaf and since then we have bought only electric vehicles.

I can’t remember what prompted us to consider solar in 2006. Perhaps it was a home energy tour in Silicon Valley that got us thinking about it. Our home in Sunnyvale was not all-electric, but rather state of the art for 1959. So, heating and hot water were still gas. And from 2004 and 2011, other than an eMoto scooter, we have no option to rely on electricity for transportation. Our electric demand in 2006 was pretty modest. So, the solar system we installed was just 2.5kW with no storage system. (Residential rechargeable storage systems in 2006 were basically stacks of 12V lead acid batteries. If used regularly they had short lives and required regular maintenance.)

Maybe it was because this was early in the home solar installation history, but installation was not without its hiccups. First, in installing the mounting brackets on the roof there were bolt ends penetrating into our living room ceiling. The early systems all had a single inverter. This meant DC current was traveling through the wires from the panels to the inverter. This required conduit for the cable even when it was going through a wall. And I received a call from my wife saving I needed to head home from work. The installers had started a fire in the wall behind our refrigerator by shorting two wires.

But the system did work finally as advertised. At the end of the first year of solar, based on those year’s utility tariffs for residential solar customers (E9), we had no electric utility cost. In fact, during the true up bill, PG&E sent us a check for $80. This resulted from the timing of the tariff tiers. Midday, when our solar panels were yielding the highest output energy, was designated in the E9 schedule as being the peak cost period. In the evening, when we consumed most of our energy, was designated in the tariff as off-peak. After midnight the rate dropped to 4.5 cent/kWh while during the time our panels were running the meter backwards, the cost was 32.5 cents/kWh.

With the experience from that first year, I had a hard time understanding a business model that could sustain delivering free energy. If this was going to continue, it would be great if the benefits to be offered to others, including renters. In my community, more than 50% of households were renters. How could we make it possible for them to participate and benefit?

I also considered that the cost of my installation was not sustainable. Construction costs of a 2.5 kW array per kilowatt were outrageous. What if instead the array was 500 kW? I wondered how the installation cost might scale. It seemed obvious that the BOS (balance of system) installation costs would be much less per kW. Clearly that was not going to fit on residential roofs and it would be good to have neighborhood energy available. So, I contacted the Planning Department in my city and asked how many square feet in the city was covered with public and commercial parking. A fast calculation using the results of what my 2.5kW array delivered and assuming other homes’ consumption was comparable to ours, it was obvious that just covering parking spaces with solar arrays would power every home in the city.

I questioned how we might make the advantages I had with my array available to others by building offsite systems in which they could be part owners.

So, in 2006 I bought the domain that I use for these current posts, scalablepower, and began working with a few friends to see if we could build a business offering this option. Like many of my ideas, the time was not right. There was no financial method available at the time to create Community Solar let alone Offsite Solar.

However, in working this problem, my education began in how we actually get our electricity. It is a complex system with a number of players, all trying to be profitable while providing a service that has less than two outages a year for any customer and consistently provides power 99.9998% of the time.

Expanded Dabbling

In 2016 we moved to our current home in the North Bay that was built in 1954. Though the house had been modified a number of times, it still was relying on 1959’s technology and design requirements. (The original electric panel, hidden behind a shelf in the laundry room still used screw-in fuses.)

After a year we began an extensive renovation to make it as safe and energy efficient as possible. Besides earthquake and fire proofing the structure, we also followed the soon-to-be passed Title 24 code upgrades that specify that the external surfaces must be thermally separated from the building interior. No structural part should touch both the interior and exterior surfaces. As well we rewired the entire electrical layout in the home so that a subpanel of critical (protected) loads designed to function during utility power outages was created. And we started to electrify all the appliances of the home. This included installing our first 2 heat pumps. (More were to follow over the years.)

Shortly afterwards we had a 4 kW array installed and paired it with a 12.5 kWh energy storage system. As I mentioned above, storage was something I had dismissed as practical when we put the solar on the Sunnyvale home. However, by 2018 practical, no maintenance battery storage systems were commercially available. (We used Shell’s Sonnen system.) Some rewiring was required to place the Sonnen system in front of the critical loads subpanel we created during the renovation. As well, because the system was not IP65 rated, an external shed was built to house the battery system and the equipment to interface the solar system.

With our new storage capability and Enphase microinverter array installed, I began reviewing the performance of the system closely to understand how to best reduce both our costs and consume our energy directly without relying on the utility to store it for us.

The utility tariffs had evolved dramatically after our first experience in 2006 to address the changing profile of energy demand. Peak cost times had moved from the midday that addressed the Air Conditioning (AC) loads to instead the evening hours. The AC load was still there, but over the past 12 years with rapidly diminishing solar panel costs, the supply of energy midday now surpassed the increased AC demand. (When the sun is out, homes heat up. But at the same time, when the sun is out, peak solar generation occurs in the same neighborhood offsetting the AC load.)

With current tariffs, in the design of a home energy system, arbitration now becomes more important than simply offsetting energy demand. In the evening hours, when costs are highest, we wanted to avoid the high utility costs. If we need to buy energy, we want to do it when the costs are lowest, during off-peak pricing period. We could no longer simply rely on solar to offset the peak costs. We need to move the availability of that solar energy to times when the sun had already set.

The new system generates detailed data about how it is functioning and how we are consuming our energy through the Sonnen system. It all seemed to be working well, but I continued to tweak the system to see if I could get the utility costs down. I found several design problems that I made.

First, I was not using enough of the battery for arbitration. In the winter when our loads were greatest during the peak cost period the battery reached its discharge limit. A simple adjustment took care of that. I increased the depth of discharge allowed to just retain 30%. (This worked fine until we had a power outage at 5 AM that lasted 24 hours due to a storm. The following day we only got 300Wh of energy back - it was dark!)

The next issue was how I had defined the protected loads. In the summer, because the system only handled the protected loads, the other loads were only serviced by utility energy even though the battery had plenty of surplus energy.

And I had undersized the battery storage capacity. Though 12.5 kWh of storage and 8kW of peak power available would cover our average electric usage, it did not capture all the energy that the solar system was generating. Throughout the year, at sometime during the day we were sending energy back to the grid even though we would need it later in the day.

More battery, more load coverage, more collection; I needed all of these especially if we continued to expand our way to an all-electric family.

Refining the System

In 2023, two things got me even deeper into thinking about solar and energy. First, we continued to expand our electrification effort. We replaced our last gas powered vehicle buying an additional EV, a 320 mile Kia EV6. Shortly before we built an all-electric studio apartment over our garage, and we finally replaced the remaining gas furnace with a second heat pump for the house. At this point our home and transportation were entirely electric.

The second thing that impacted my thinking resulted from what I learned as a number of us worked to make a pitch to PG&E. We proposed PG&E expand its business and offer a new product. If PG&E provided controllable onsite storage in front of the meter, PG&E could become the premier provider of DERM (a topic covered in a number of my other posts.) After all, PG&E primarily makes its profit from delivery of the energy, not the energy itself.

Now with the two EVs and driving 16,000 miles a year, I realized that we needed more electricity to support the growing demand from the second car. So, additional panels were scheduled for installation and my work on the proposal to PG&E gave me an idea of how I wanted my home system to function. When the utility is up, I wanted my home storage system to support not just the critical loads panel, but to discharge and reduce utility costs for any load from the house (cars, garage, dryer, stove, oven) It turned out, once I described this to my solar installer, he said Sonnen had a product to do just that. It was called the Whole Home option on my existing Sonnen system. With this option, the Sonnen system gets two sets of input. One set tells it how energy is flowing through the utility meter (how fast and in what direction). The second is monitoring the protected loads.

Once the Whole Home option was installed, I started seeing the entire load my home is experiencing every second, how much energy the panels are generating, how much energy is being supplement each instant by utility power, and how much energy is flowing back to the utility when the panels are generating more than we are consuming or can store.

After 2 full years of history with this configuration, the two EV, and basically an all-electric home, I can understand the factors that need to be considered as a home electrifies and introduces solar and storage.

I think about our electric profile like this for 2025:

• we drive 15,000 miles/year and consume 4,000kWh in the cars,

• Our home uses besides the cars consume about 6,100kWh /year

• Our 20 solar panels collect and deliver 7,400 kWh/year

• We sent 4,000 kWh to PG&E

• We bought 7,400 kWh from PG&E

I think you can see part of the problem. Besides the losses of not consuming directly what we produce, we are paying for the cost of moving the 4,000 kWh energy back and forth. Lucky for us, we are under a tariff that penalizes this very little. For new solar installations, this is not the case. There is a larger penalty if you have the utility store your energy for you (even if it is just for a few minutes.)

I am not convinced it is our responsibility to collect as much energy over the year as we will consume. Clearly if you plan to go off-grid, you would need to size your system appropriately. But regardless, larger battery sizes are required than what is your average daily usage. Heck, there are days with little sunlight and curiously they seem to correspond with the times when you need your battery to support you.

Maybe the simplest axiom is design your system so that you don’t need to export energy back to the grid. That is not as simple as it sounds. Unless you drive a lot every day, try figuring out how you might consume 32 kWh a day during the summer (about 120 miles of driving). That is not hard to use in the winter, but in the summer that consumption can drop to 8 kWh.

The Next Phase

At this point, I need to take some of my own advice. Add more storage! The question is how?

I can upgrade the Sonnen system, but because of some physical constraints that could be both disruptive and costly.

I have been exploring attaching an IP65 rated battery system to outside of the studio wall. The part I don’t understand is how it would recognize when it can discharge and ideally I would want it to charge only when solar energy is being collected. This is an option I have been seeing in many of the new integrated systems. Obviously, it requires the solar to communicate with the battery system. But with the Sonnen battery how would it know they were both taxing the one system.

The other option is to leverage the 100 kWh of battery storage sitting in my garage; the EVs. That is my current investigation. It will likely be pricey, but it will be interesting to learn how a system 120 ft away from the meter can work intelligently to optimize our energy system.

Yo que tú

My lessons learned might be summarized with these points:

• Figure how to reduce the costs paid to the utility. Install a solar array sized to match home needs. Too large an array is as bad as too small an array

• No matter what you decide - it will not be perfect year round. In my climate zone, I will be getting too little return for the energy produced in the summer, or will be paying too much to the utility in the winter. You need to find a goldilocks solution.

• Send as little of the energy back to the grid as possible. Size the storage based on the solar capacity, not the home requirements. This often means larger than the solar will typically generate, as you will want to keep some buffer for the occasions during utility power outages (that seem to occur just as your battery is discharged the most.)

• Cover the entire home with the battery storage when the utility is up. This increases the benefit you get from arbitration.

• Find a smart installer you can trust that takes the time to understand what you want to accomplish; and who will be there as long as the warranty on your equipment.

• Be energy efficient and rely on electric appliances! Insulate and use heat pumps, modern lighting, inductive ranges. In doing this, we reduced our energy consumption by 60% and gained a much more comfortable home.

If you start on this journey and have new lessons to share, let me know.

Appendix: Arbitration thoughts

If you made it through my story and learning process and you still want to dig in and start “electrifying” your self, I am providing this section with some of the terms and explanations of how the money works out when you consider how to use your system to arbitrate costs.

If arbitration is a foreign term to you, in the financial world it means to buy low and sell high. That is what we are trying to do with our home energy system. We want to buy energy when it is cheap and avoid buying when it is expensive. We do that by filling our batteries with low cost energy from either solar or from the grid at off-peak periods and discharging it for our home loads when the utility energy is at its peak price.

This is a short section, there is obviously a lot more could be covered, but I hope this gives you a starting place.

Tariffs

If you are trying to manage your energy costs, then education on the tariffs and tariff options is important. Our local utility, PG&E, used to give day long classes on this at their Energy Center in San Francisco. You probably don’t need that much education, but you do need to understand Time-of-use (TOU) vs Tiered tariffs.

Tiered tariffs were predominant until about 10 years ago. They were designed to incentivize customers to be more efficient. As you use more energy, at certain total consumption thresholds each month, the per unit cost would go up to a more expensive tier. (Some areas with municipal utilities still use this method and natural gas is still priced this way.)

With TOU there are normally 3 periods defined; off-peak, partial-peak, peak. The per unit price is different for each. Each tariff has specific hours when these rates apply and the rates for each may change depending on the time of year and specific climate zone you are in.

I was surprised to learn recently that though the structure of the tariff (when periods are and how they are adjusted) is stable, the actual price in each period can change based on adjustments the CPUC authorizes.

In California, the regulated utilities are being forced to convert all customers to TOU by 2027. Originally it was solar and EV customers who took advantage of TOU schedules. But over the years, with changes in the tariffs you might change the word from advantage to deal with as the peak cost periods no longer align with the peak solar periods.

Battery Schedule

The system I have, Shell’s Sonnen Battery system, has three distinct modes it can run in. A fourth is being added, but my old manual does not describe how it functions.

Though other systems might have different names or slightly different behavior, you can assume any system will provide at least these options.

• BACKUP - basically the battery gets fully charged and only discharges if the grid becomes disabled. Curiously, this is the mode most people use, because they think of the storage as a guarantee of energy. It is something the local CCA is trying to train people out of.

• TIME OF USE - here we configure the storage so it knows the utility Tariff. It attempts to shave the cost by discharging only during the peak or partial peak periods where the cost is higher. The rest of the time it is either filling up or just lazing around. The real value of battery storage both to the consumer and the grid operators every day is when it is used to do arbitrage during peak periods.

• SELF_CONSUMPTION - In this mode, the storage system is always willing to discharge in order to stop consuming grid energy. It does not know about peak expense periods, but treats all periods the same. This was the mode we were advised to NOT use since you might run out of energy when prices are expensive.

  This summer since my battery was not ever discharging more than 12% and I was sending all my solar energy back to the grid, I decided to try using SELF_CONSUMPTION. and yep, my self-sufficiency went up.

Successful arbitration using the Time Of Use is one way to reduce the cost of your energy. As an example, the current tariff at my home has a peak rate of 62 cents/kWh and an off-peak rate of 32 cents/kWh. So, my goal is to avoid paying the higher rate.

When I calculate my full cost over a year’s time for the 10,000+kWh our home consumes, the average cost comes to just 16 cents/kWh.

I had expected to quickly answer that question, but as I thought more about it I considered it deserved a deeper answer than I was prepared to post at the time and questioned whether what I propose has legs. So, I am hoping as you read and review this you might offer your opinion and ideas.

How did I get interested in this?

In 2023 friends and I created a small team to respond to a solicitation by our local utility, Northern California’s PG&E. As I mentioned in previous posts, the utility posed a number of problems during their July 2023 Innovation Summit. They asked attendees to offer solutions to each of 70 problem statements that they organized into 6 general categories.

We decided to respond with a solution that we felt addressed a number of the problem statements in three of those categories; Supply and Load Management, Integrated Grid Planning, and Electric Vehicles. Our focus was in restructuring the existing grid assets in such a way that it could more easily accept Distributed Energy Resources (DER). In doing the research, we tripped over a new term to us, DERM, Distributed Resource Energy Management.

I don’t want to argue here that our specific solution was THE right one. (If you want to see our pitch, you can find our Smart-Stor solution posted on scalablepower.net.) However, our specific solution relied on a general direction that I believe to be the most productive approach. It might be summarized by this:

That’s a very short statement and it doesn’t cover the depth of what it means. But it does suggest that as DERM replaces our model that relies on centralized energy supply, that the utilities themselves become the primary DERM provider.

Utilities are actively adjusting

Curiously, California’s utilities have been following parallel paths. Many of the new power contracts that utilities execute call for Virtual Power Plants (VPPs). One form of VPP is done using home solar and battery installations. The power provider signs a contract with building owners when they install the system. Once the system is live, the supplier retains the right and ability to either curtail utility power or to discharge the battery storage to the grid for a certain number of hours per year at a limited power level (kW level). When the utility conveys to the contract holder that the grid needs support, a signal is sent to a number of building systems that triggers them to perform. In this regard the VPP very much provides the same function as natural gas peaker plants operating today, but instead of being in a single location, the VPP power may come from hundreds of building installations.

The other method of leveraging DERM which utilities are just initiating is by tapping the energy in Electric Vehicle batteries. In this case, they are financially supporting installation of Vehicle to Grid (V2G) charging stations in hopes that in the future they will be able control both the charging and discharging of these large EV battery systems on demand.

In both of these cases, the strategy is to replace the existing need for peaker plants power and to affect simple demand moderation.

Utilities are also attempting to minimize the impact on the grid of those uncontrolled behind-the-meter sources of power (in the form of solar arrays) have on the grid. By using tariffs as negative incentives, the hope is that the impact of these systems can be isolated from the grid by promoting new systems to always include storage in their design.

If you look closely at what features that utility-supplied distributed energy-storage could include, it becomes obvious why a solution that integrates tightly with the utility’s distribution grid and the utility’s mission would be a superior approach.

Why are we suddenly talking about this?

Over the past 30 years we have developed cost-effective methods of producing electricity near the consumer. It comes as no surprise that capture of solar energy and converting it to electricity is the primary method of doing this. (And solar energy after all, with the exception of nuclear and geothermal, is ultimately the source of all the other forms of energy that we tap.) The dramatic drop in cost of solar is making this a compelling solution.

The typical solar panel cost in 1990 was 10 dollars/watt. Today that typical cost is 10 cents/watt. Adjusting that value for inflation, there has been 250 fold reduction in panel cost over a 35-year period. With the typical system lifetime of 25 years, installed in my climate zone in Northern California, that results in a delivered cost around 13 cents/kWh. If I review rates around the country, the lowest delivered utility provided energy averages 12.7 cents/kWh and the highest is 52 cents/kWh.

It is often hard to understand these costs when we learn that wholesale electric energy cost can be as low as 4 cents/kWh. It seems like quite an unreasonable markup! That’s where we start to understand the impact of the cost of delivering the energy to our homes. The benefit of distributed energy resources is the delivery cost is already included since ideally it would never use the distribution grid.

I went down this rabbit hole just to explain that the real reason for considering Distributed Energy Resources is cost reduction. But at the same time the real problem with distributed energy is the lack of control. It is that control of supply which has guaranteed us the 99.999% uptime we take for granted.

One might argue that we should centralize the generation and still rely on these more efficient and lower climate-impacting direct solar sources. Why? We are finding ways to reduce the losses from transforming primary energy resources into usable electric energy, but we have not found ways to reduce and simplify delivery to the ultimate consumer.

Implementation of Distributed Energy Resources can deliver more than simple cost reduction. It can simplify and balance the grid without requiring that the existing transmission and distribution grid be renovated. However, in order to do that predictably, positive control that balances supply and demand is required.

It is time to think differently (or as André Schwager would say, think orthogonally).

Centralized Control

In an earlier post, I explained why I believe the utility requires such extensive review of the solar and storage systems we install on our buildings. It has to do with ensuring the controls are in place so that the electric energy shape and stability is not compromised; and that the wires and transformers in the neighborhood that comprise the distribution grid are sized for these changing demands. After all the utility has given up the one thing that gave them a chance of providing reliable power; control over the supply.

Recent tariffs here in California that support solar installations are under NEM3. This series of tariffs pay very little for feed-in energy (the surplus our home solar systems send back to the grid when we cannot consume it all at a particular instant in time.) The rationale (I believe) for this tariff change was NOT to slow down the rate of new solar system installations. Rather it was to incentivize new installations to always include storage in the system. Basically, the utility and the California Public Utility Commission are attempting to employ tariffs to restore control over the supply. I think this is not the most successful approach for a number of reasons.

The first of these is Control. Historically, the utilities could send signals to plants to increase supply on demand. For gas-powered peaker plants bringing this power online could occur in as little as 5 minutes. Contrast this to a solar system. How does the utility tell the sun to move to a good position or make the clouds evaporate?

You could take this and use it as an argument against relying on solar at all. And I would agree. As I discovered with my first experience installing a solar system, a solar array without a storage system to handle the timing of the delivery of the power is a losing proposition. But even with storage, if the system is designed and configured to support the goals of the system owner, it cannot be relied upon to support the instantaneous needs of the distribution grid.

The second reason the solutions are being employed today to support DERM is Scope. As I am writing that sentence, I am challenged to explain why I think this is significant and indeed what I mean.

Today a fairly limited number of households in PG&E territory (our local utility) have solar and storage installed. The PG&E contract with Sunrun for VPP covers 8500 homes and offers 34 MW of power. In that same territory it is estimated that there is between 2200 and 4400 MWh of storage. That 34 MW is quite a bit smaller than the smallest gas peaker plants which offer 50 MW on demand.

But there are 5,000,000 households in the PG&E territory. If the scope of the solution extended to all those households as part of the utility offering, the utility would have up to 20,000MW of power it could call up.

Scope makes a difference when you are relying on a primary energy resource that itself can’t be controlled.

The Solution

The onsite utility energy storage should be able to actively participate in balancing the distribution grid. To do this, the proposal we sent to PG&E suggested the utility should have the ability to directly increase demand when a distribution branch is experiencing excess power; and increase supply and decrease demand when that distribution branch power is sagging.

Distribution of Supply paired with Fine-Grained Control

By having controls throughout the distribution network, fine-grained control of power on the line at any point in any neighborhood could be instantaneously maintained. Even during a grid outage, the neighborhood could be assured that power would continue to be available.

The key is to eliminate peaks in both demand and now in supply. Intelligent storage systems that are filled both from the grid and from local solar can be used to maintain that neighborhood grid. This would be provided in the in the form of a device installed by the utility in front of each customer’s meter. Key is how the device functions.

The device would function based on GOALS. These could be in the form of voltage levels to be maintained, energy capacity buffers, and constraints on how much management is permitted. And the device would need to provide value to both the utility and to the customer.

It is obvious what some of the components of this system might need. Certainly, storage is the primary component. But as any family living with a behind-the-meter battery storage today learns, it is not just having the energy when the grid goes down. The battery is used whenever you have demand in the building in order to reduce what is needed from the grid. And the battery has to have headroom (space) to storage energy when the home is using little and the solar panel are generating surplus. Again, this is to reduce the amount of energy flowing onto the grid. But the battery, as utility resource could also be used when your neighbor has too much or too little energy available.

With that last example, you might recognize the other dimension of SCOPE that the utility controlled storage satisfies. A neighborhood solution starts to evolve and replace the single home solution.

There are other components the system needs. There is a power module. This ensures the power is delivered at the right time, has the right frequency, and is in phase with what the grid expresses.

A logic engine is in place to determine the best way the device can function to satisfy the grid and home power and energy goals. This needs to be pretty intelligent as it considers weather patterns, solar performance over time, and the household’s typical demand pattern. Completing much of this analysis would require recording and storing past patterns, so a place to store that data and insuring it is secure on the property is required

A full system could be paired with a wifi connection that might control high sustained demand. With the transition to Electric Vehicles, which typically get refueled at home, it will be necessary at times to limit the number of vehicles drawing power in the neighborhood at one time. Either signals to devices or now emerging wifi-controlled circuit breakers make this level of control easy to install.

And finally, communication that allows the utility to both monitor the system, send software updates, and to periodically when needed modify the goals the devices follow in a neighborhood

Summary and Soapbox

I recognize that I am a bit locked onto a typical solution. There is a lot of sentiment against our monopoly utilities and assumptions of their motives (profit). But I question if the behavior they express is strictly driven by profit. I believe most of the tariffs and business direction is in driven by a need to get CONTROL. And the rationale for that is not to increase profits so much as it is to provide a reliable service.

When I describe this DERM solution, most people object to it because I suggest the utility should be the one to implement it. Admittedly, it is an expansion of their business. But for me it is an expansion that would benefit each of its customers, those with solar, and those that don’t have it.

A neighborhood solution….

Leave a comment

So the last of these, A.I., recently has led to a lot of reading and arguments with my friends. I realize how much I rely on my calculator, my phone (actually mini-PC), and all the other modern electronic helpers we take for granted now. I am disappointed in how much less I process between my ears, instead relying on my fingers to do so many calculations and retrievals.

One of my best friends insists I have a bad attitude about this. He is using A.I. engines to improve his firm’s service products. He subscribes to my Electrify post and decided to ask his engine (Claude, no last name) what was wrong with my post.

Well I will relieve you of having to read the specific criticisms of my research and writing, and will simply offer you Claude’s version of that same 21st Century Grid Challenges post for fun.

21st Century Grid Challenges: Beyond Simple Electrification

Gerald Glaser as rewritten by Claude
Nov 16

In my previous post, I explored how the electric grid functions and why its operation is remarkable. Now I want to examine why yesterday’s solutions won’t solve tomorrow’s distribution challenges—and propose a more nuanced path forward.

The Scale of Change

From 1900 to 2000, world population grew 3.8-fold while energy use grew 8.5-fold. In the United States specifically, energy consumption increased from 2,700 tWh to 28,633 tWh—a tenfold increase—while population only tripled. This disproportionate growth in energy intensity has defined modern life.

The transformation wasn’t just in quantity but in form. In 1900, primary energy sources were coal and wood, burned directly for heat. By 2000, our energy mix included nuclear (8%), coal, natural gas, petroleum (40%), and renewables (7%, primarily biomass and hydro). But this shift in sources masks a more fundamental transformation: the conversion from primary heat energy to electricity.

The Efficiency Paradox

Throughout the 20th century, when energy primarily meant burning fuel for heat, direct combustion made sense. But as we needed energy for transportation, lighting, and complex machinery, electricity became essential despite its conversion losses.

Converting fossil fuels to electricity wastes substantial energy at each transformation step: chemical bonds to heat, heat to mechanical motion, mechanical to electrical. According to Lawrence Livermore National Lab’s 2023 data, of 93.6 quads of primary energy harvested in the U.S., 61.5 quads (66%) were rejected as waste heat before doing any useful work.

When electricity was a luxury, this inefficiency was tolerable. Today, electricity consumes 22% of primary energy, up from 0.1% a century ago. With building electrification, electric vehicles, and new industrial processes like electric steel production, this percentage will continue rising sharply.

What the Numbers Actually Tell Us

We’ve achieved remarkable efficiency gains: buildings are better insulated, LED lighting is 90% efficient versus 5% for incandescent bulbs, hybrid cars achieve 50 mpg, and aircraft have dramatically improved fuel economy in just twenty years.

Yet total energy consumption—and especially electricity demand—continues growing. This isn’t a failure of efficiency; it’s the Jevons paradox in action: as energy use becomes more efficient and cheaper, we find more applications for it.

Here’s where the scale becomes clear. My household provides one data point: after insulating our home, reducing appliance loads, and converting to all-electric systems including two EVs, our total energy consumption dropped 62%. But our electricity consumption nearly tripled. If this pattern holds broadly—and early data suggests similar trends—the distribution grid faces an unprecedented challenge.

To put this in context: PG&E serves approximately 16 million people. If even a quarter of households follow similar electrification patterns over the next decade, the distribution system would need to handle roughly 50-75% more peak capacity in many neighborhoods. The current grid wasn’t designed for this.

The Supply Question: Largely Solved

Several years ago, I attended a board meeting where our local electric utility presented load forecasts to the California Public Utilities Commission. Their model projected minimal demand growth, assuming efficiency gains would offset new electric applications. That assumption is being rapidly reconsidered.

But can we actually generate enough clean electricity?

The answer appears to be yes. In 2024, the EIA reported that new generating capacity broke down as: 58% solar, 13% wind, with nuclear beginning to ramp up again, while fossil fuel plants represented only 4% of additions. In my region, advanced geothermal facilities are being developed that can be built almost anywhere by tapping deep earth heat.

Total new capacity in 2024 was projected at 62.8 GW—55% more than the 40.4 GW added in 2023. For context, total U.S. generating capacity is approximately 1,200 GW, so we’re adding roughly 5% annually, with renewables dominating. At current growth rates, generation capacity should keep pace with electrification, though regional bottlenecks and timing mismatches will create challenges.

The generation problem has technical and economic solutions. The distribution problem is more complex.

The Cost Question: More Nuanced Than It Appears

A builder I spoke with recently questioned whether the grid can handle growing electric demand. His concern: “Where is all that energy coming from? It’s really expensive compared to existing fossil fuel options.”

Let’s examine this carefully.

California has the second-highest residential electricity rates in the nation at 30.72¢/kWh (after Hawaii), compared to North Dakota’s 7.42¢/kWh and a national average of 15.59¢/kWh. This disparity requires explanation.

Natural gas prices are highly volatile: $9.33/MMBTU in 2022, $1.63/MMBTU in 2024, currently $4.31/MMBTU. PG&E charges $6.70/MMBTU for the gas itself, plus $22.20/MMBTU for delivery. This means delivery costs represent 77% of what consumers pay.

Even if gas prices double, consumers only see a 23% bill increase because delivery dominates the cost structure.

Electricity pricing is more complex, with Time-of-Use schedules, seasonal variations, and zone-based rates. During winter peak periods, 67% of electricity cost is delivery infrastructure; in summer it drops below 50%. California’s high rates stem largely from aging infrastructure and wildfire damage liability—costs that should decrease as utilities underground lines and improve safety systems. PG&E has already reduced residential rates in the past year while promising further reductions.

However, this cost comparison misses critical factors:

Equipment efficiency matters. A heat pump with a coefficient of performance of 3.0 delivers three units of heat per unit of electricity consumed. Even at California’s high rates (30¢/kWh), that’s effectively 10¢ per kWh-equivalent of heat. Natural gas at PG&E’s total delivered price of $28.90/MMBTU, burned in a 95% efficient furnace, costs roughly 10¢ per kWh-equivalent. The economics are already comparable in high-cost electricity markets, and favor heat pumps in most other states.

Total cost of ownership varies dramatically. Installing residential solar and batteries requires $20,000-$40,000 upfront. Not everyone can afford this, and renters, apartment dwellers, and those with poor solar exposure have no access to these solutions. Natural gas infrastructure already exists in many homes.

Long-term price trajectories are uncertain. I claim electricity will become cheaper relative to gas, but this assumes continued renewable deployment, stable policy support, and resolution of grid integration challenges. Gas prices could remain low if fracking continues, or spike if exports increase or regulations tighten. Making 25-year predictions about either fuel’s relative cost is speculative.

My fundamental position: over the 15-25 year lifespan of HVAC equipment and appliances being installed today, electricity will likely be cost-competitive or cheaper than fossil alternatives in most markets. But this isn’t guaranteed—it depends on policy, technology learning curves, and infrastructure investment.

The Question Everyone Should Be Asking

The real challenge isn’t energy generation or even long-term costs. It’s the distribution grid—that final mile from substation to home.

As I explained in my previous post, peak demand determines grid design: conductor sizing, transformer capacity, and branch circuit extent. If households triple their electricity consumption while also changing the nature of peak demand—EVs charging for hours instead of air conditioners spiking for minutes—the distribution system becomes a bottleneck.

Utilities face three options:

1. Massive infrastructure replacement - Upgrade transformers, conductors, and substations across entire service territories. Cost: hundreds of billions nationally. Timeline: decades. This is economically prohibitive.

2. Managed demand - Smart thermostats, dynamic pricing, vehicle-to-grid technology, and direct load control can flatten peaks. This helps but requires coordination, customer acceptance, and sophisticated control systems. It’s part of the solution but not sufficient alone.

3. Distributed generation and storage - Rooftop solar and home batteries can meet local demand, reducing distribution requirements. This is promising but excludes many customers and requires new regulatory frameworks for grid integration.

The realistic path forward combines all three: strategic infrastructure upgrades where needed, aggressive demand management, and distributed resources where feasible.

But here’s what’s missing from most discussions: who pays, and how do we ensure equity?

Wealthy homeowners can install solar and batteries, insulating themselves from high rates and grid constraints. Renters and apartment dwellers cannot. If utilities raise rates to fund infrastructure upgrades, they disproportionately burden those who can’t invest in self-generation. If we rely too heavily on distributed resources, we create a two-tier system.

What Comes Next

We cannot produce or store natural gas at home. We can collect solar energy and store it in batteries. This asymmetry suggests a path forward that utilities and regulators are still grappling with: a hybrid grid model where distribution serves as backup and balancing rather than primary supply for many customers.

In my next post, I’ll examine one approach to this transformation—how residential solar, batteries, and smart controls could reshape the distribution system while addressing both cost and equity concerns. The solution isn’t purely technical; it requires rethinking the utility business model, rate structures, and our definition of grid reliability.

The question isn’t whether we can electrify everything. We can. The question is whether we can do it affordably and equitably, without stranding those who can’t participate in the distributed energy transition.

!!OK, I fold!!

From 1900 to 2000 the world population grew 3.8 fold, while at the same time its energy use grew 8.5 fold. Considering these are worldwide statistics, and much of the world has not had the benefit of the energy use explosion, this is quite a change. From the U.S. EIA the energy change over that same period in the USA was from 2,700 tWh to a whopping 28,633 tWh while its population only grew 3 fold.

Over that same period a major transformation in the primary sources of energy occurred. Primary energy is the harvested source of the energy. For much of the beginning of the 20th century little transformation occurred from the primary energy form to a usable form. In 1900 the primary source forms were coal and wood. In the 1950s we were promised that nuclear power plants would provide us virtually free electricity. (It didn’t happen.) By the year 2000 what nuclear (8%) we had was supplemented by coal, natural gas, and with 40% being petroleum. Renewables (7%) at that time (primarily biomass and large hydro) were a relatively small portion of the energy mix. However, that is not the whole picture.

So throughout the 20th century coal, wood, natural gas, and petroleum were the predominant forms of primary energy. They were simply burned, converting their physical chemical bonds to heat.

If you are relying on the energy to heat and cook - that seems reasonable. However, as we started to use this energy to power transportation, provide light, and run modern machines, heat simply was not the most efficient form of energy to use. Electricity provided a more convenient and effective form. It seems obvious that rather than focusing on the primary source of energy, planning for the future we needed to focus on how the energy is distributed and consumed to do work.

Following our established pattern, we began converting those 20th century sources of primary energy to electricity. In most cases this was done by transitioning from chemical bonds, to heat, from that to mechanical engines, and finally to electricity. Each transformation step resulted in waste energy being released. From the Lawrence Livermore National Lab’s 2023 USA Energy Consumption diagram we see that of the 93.6 quads of primary energy sources tapped that year, 61.5 quads were rejected and never utilized to complete useful work.

When electricity was “nice to have” this was an inefficiency that could be tolerated. But today, even with us continuing to consume enormous amounts of fossil fuels for transportation and heating, electric energy has grown from consuming 0.1% of the primary energy to now consuming 22% of it. You can guess as buildings are electrified, with the introduction of electric vehicles, and even new processes for making steel; this transition is just the beginning.

So what’s the point?

We have been achieving amazing results in improving our efficiency in the use of energy. Our buildings are better insulated, lighting has moved from being 5% efficient to over 90% efficient, hybrid fueled cars are driving 50 mpg, and even aircraft and ships have made enormous improvements in efficiency in just the past 20 years. Yet our consumption of energy for all the things we want to do, and especially the intensity of electric energy use, continues to grow.

Several years ago I attended a board meeting of our local electric power provider. Each year here in California, load servicing entities (providers of electric energy and power) are required to report to the California Public Utilities Commission (CPUC) how they will ensure sufficient energy will be available for their future customer needs. At that meeting their model showed, as a result of efficiency measures, even with a growing population, that there was little growth in demand forecast in the future. Their assumption was that the savings achieved from more efficient technologies would keep up with the expansion of the number of applications that would rely on electricity as its usable energy source.

I believe that is now being rethought.

After improving our own home by insulating, reducing the appliance loads, and converting to an all-electric home, our electric energy consumption had doubled. Then we replaced our remaining car with another electric vehicle for our longer trips. At this point, as I reported in earlier posts, we had reduced our family energy use by 62%. That sounds great! But at the same time, our electric energy consumption increased close to 3 fold.

So what does this all mean?

In the past week, I met with someone in the building trade that questioned whether the grid can keep up with the growing demand for electric energy. In construction of new buildings and remodels, they are encouraged to use heat pumps and all electric appliances. His question was. “Where is all that energy coming from? It is really expensive compared to the existing [fossil fuel] options.”

I did have answers to that question and concern.

Where is all that energy coming from?

In 2024 the EIA identified of the energy proved from new production facilities some 58% were solar fields and 13% came from wind turbines. Nuclear is once again beginning to ramp while fossil fueled plants only amounted to 4% of new energy sources. In my local area new facilities are being built to tap advanced geothermal energy. These are facilities that can be basically constructed anyplace in the world and rely on the hotter temperatures found as you drill deep below the earth’s surface.

The above are just the utility scale additions to the energy portfolio. Again from the EIA, 62.8 gigawatts were projected to be added in 2024; this was 55% more additional capacity than the 40.4 GW added in 2023.

Basically, we are already starting to find ways to address the raw need to harvest energy sources that will not rely on burning materials. So the answer to the question of raw capacity seems to be being answered.

It is really expensive compared to the existing options.

This was an interesting comment and I kind of understand where it is coming from.

Electric energy costs in California are extremely high. After Hawaii, California has the second highest residential average cost at 30.72 cents/kWh. Contrast that with North Dakota at 7.42 cents/kWh and an average of states’ averages of 15.59 cents/kWh.

So how should I address this comment? Well there are two factors that say this long term will not be an issue.

The first factor is the forecast price change for the conventional alternatives to electricity. Primarily this is natural gas (methane).

I tried to find a source for projections for where natural gas prices might go over the next 25 years. I couldn’t find any. So I looked at the prices over the past 5 years and I learned how volatile natural gas prices are. In 2022, it was as high as $9.33/MMBTU (million BTU) and in 2024 it dropped to $1.63/MMBTU. Today it is at $4.31/MMBTU. But our local utility, PG&E, is charging us $6.70/MMBTU as of December 2024. Likely this up-charge is to address the basic volatility of the gas price.

But utility rates are broken down into a number of general parts; the energy, fees and taxes, and a delivery cost. Of the total cost to the consumer, our local utility also charges an additional $22.20/MMBTU to deliver the gas.

This brings up a point so often lost as we discuss utility rates. The cost of delivery of the energy most often determines the cost we pay as consumers. With natural gas this is obvious. So even if the gas rate varies by 100%, the consumer would still only see a 23% change in the cost, because the cost of the gas is such a small portion of the delivered price.

With electricity the picture is quite a bit more complicated. There are many different schedule rates; and variations even within them based on where you live. As well California utilities are required to shift their residential customers from tiered rates to Time-of-Use rates. So determining average costs is tricky.

As an example of this complication, the TOU EV-2A schedule has winter and summer rates. Each season has prices for peak, partial peak, and off-peak times. And these are adjusted based on the zone in which the building is located and whether or not the primary heating source is natural gas or electric. During the peak period in the winter, 67% of the cost of the electricity is the delivery cost, while in the summer it is less than 50%. So electric rates can be more sensitive to the energy costs than natural gas is.

I questioned why California electricity rates were so high compared to other states. In a large part it is our aging infrastructure and the cost of damages caused in wildfires triggered by the electric grid.

This was proven out in the past year as resulting from efforts to reduce the risks associated with transmitting electricity, PG&E has been able to reduce residential rates. The letter announcing this reduction included a promise to continue to focus on reducing rates.

So my fundamental response to the statement that electric energy is more expensive is, yes, for now! But looking forward through the life of the equipment being installed in the buildings, that will not be the case.

The question not asked.

I felt that there is a question that is often ignored. We are going to continue to increase the amount of electric energy we consume in our homes and workplaces. But as I suggest above, the challenge is not so much where to harvest that energy, but rather how to deliver it to the consumer (us). This brings the question of the distribution grid, that final mile to get to the consumer.

In The Maligned Grid post I explained how peaks determine the constraints that drive how the distribution grid is designed. It determines both the size of the conductors and the transformers, and I assume, also the extent of how large each branch can be. If each of us begins to triple the electric energy we consume (as my household did, even as it reduced the energy it consumes), the distribution grid will be under capacity to handle the change. As well, as described in previous posts, the definition of peak will need to be modified. Electric vehicles will hold peak levels for hours instead of for minutes.

The question not asked is ,
“How will we address the new distribution grid challenges without having to incur the cost of replacing those grid resources.”

We can’t actually produce natural gas at home. In fact, it is not even practical to store it at home. As we all know, we do have methods to collect energy (from the sun) and store it at our residences (in batteries). So we can mitigate the impact (and arbitrate the Time-of-Use rates) for our growing number of electric appliances.

The subject of the next post will focus on that mitigation. It will review one approach that could be taken transforming the grid, while allowing utilities to avoid expending substantial capital attempting to support our growing electric energy consumption.

Hopefully that post will provide an answer to The Question Not Asked.

I have been away from posting for months now. I kinda missed it, but I was diverted to other things.

Ok, that was actually written almost a year ago… and I never finished that post. 2024 was a rough year. I started to question what is important as result.

I started writing an other post last year that began with, “we are branching from the 20th century into the 21st. “

There was a major transition that occurred in the 20th century that those of us who arrived in the middle of that century might not have recognized.

One might argue that throughout pre-20th century history, major changes have occurred that impacted large populations. Several come to mind; the discovery of the wheel, the utility of fire, the number zero, the printing press, calculus, the steam engine, … They all had major impacts on large populations. But for each, they surfaced far apart in time and took a relatively long time to become pervasive.

As we leave the 20th century behind us, consider what you have seen change during your life. Not one discovery, but dozens of major discoveries, all surfacing during a single lifetime. And each of these impact virtually everyone in the world to some extent. Just consider how you communicate and how you get information ( or how I am communicating with you right now). It is not only the rate of change and the rate of change to those things that changed, but also, the extent to which it has impacted billions of people. (Cell phones that became affordable less than 30 years ago are a good example. There are 74 countries in the world with higher per capita cell phone usage than in the USA. And there are only 195 countries.).

         It IS kind of overwhelming to consider.

There are many topics that could be considered to demonstrate the extent of this revolutionary change, but I will leave those topics for another time (or someone else’s posts) and continue to focus on ENERGY.

Some background - My energy history

As I described in an earlier post, our first home solar installation was in 2006. It was modest in size by today’s standards; just 2.5kW. We did not pair it with batteries. Storage at that time both required extremely high cost and maintenance effort. So we decided that storage was not going to be part of our system.

Along with this solar, we got to leverage features of PG&E’s E9 tariff. This tariff was simple. It was our first time-of-use tariff replacing the tiered tariff that was customary at the time for most homes. It had a special (and simplistic) incentive feature. When we produced energy from our solar array, the meter would simply run backwards. And the meter was interesting. It was designed specifically for that tariff. In the summer, the day rate was 32 cents per kWh and after midnight it was just about 5 cents per kWh. The meter recorded the NET usage for each period and the meter reader came by monthly to record the various period values.

With this E9 tariff and as early EV drivers, we charged the car after midnight. We even scheduled our clothes drying to take advantage of the low nightly rates. The modest array collected energy and either supplemented our usage or sent it back to the utility. As a result, at the end of the first year, we not only reduced our electric bill - we actually didn’t have to pay anything. Though we consumed more energy than our little array produced, we were selling energy to the utility at $0.32/kWh and buying it for much less. Each August PG&E sent us a check for something like $80. They owed us!!!

I have to admit, as a business person I saw this as NOT a very sustainable business model. Here I was, the customer, getting a service from PG&E (reliable power and energy whenever I needed it), and they were paying me for the privilege of doing that! If I thought about it, it was even worse! They were now providing a brand new service to me. Because I had no batteries, they were storing my energy for me. That saved me both cost and bother.

At the time, I thought to leverage this unfairness to my advantage and attempted with some friends to launch a company (Scalablepower) to provide neighborhood energy systems where people could subscribe and own portions of offsite power solar systems. The startup never launched, but that’s when I began my journey in learning more about the grid and the power system we all enjoy.

Electricity? We get it delivered to our homes…

Contrary to many of my fellow utility customers, I have great empathy for the challenges our public utilities face.

When I began this post (a year ago) I characterized a shift from the 20th to the 21st century with a particular focus:

We moved rapidly from an energy light world into an energy heavy world.

My grandmother’s 1915 neighborhood home was initially built no electric connection. Electricity was a luxury. 30 years later it was common to have electricity to provide light and a few other conveniences. But today can you imagine your life without electricity? It powers much of our homes and even more of our businesses and factories. Without it much of our daily routine crumbles.

I have attended a number of forums where there are discussions regarding reductions in renewable energy incentives. Rapidly the group discussion degrades into complaints about how the greedy public utility is just trying to increase profits. Okay, some of that might be correct, but I think we need to recognize the challenges those utilities are facing as our electric grid transitions to address 21st century realities.

My posts thus far have focused on energy; how we use it, where it does come from, and where it should come from. But in a recent neighborhood meeting I realized that very few of us actually recognize how complicated and (quite frankly) fragile is the energy world we live in. AFter talking with my neighbors, I felt I would focus this post on the basics, as I understand them, of how that electricity reaches us.

Our local utility’s published uptime target is 99.999%. I like numbers - how much time does that say they expect that its customers might be without electricity in a year. It comes out to 5 minutes and 15 seconds. I find that quite a high performance goal.

Most of us don’t recognize it, but for utility electricity to be usable it needs satisfy a number of concurrent metrics. It needs to be at a particular frequency (here in the USA that is 60 cycle/second), with a specific voltage (your wall outlet is 120 volts), of sufficient power (we will get to that later), while coming from multiple sources (there are many power plants that feed the grid.)

Our homes receive alternating current (AC) energy. Basically it means the electricity moves back and forth instead of just in one direction. (Easy to understand how that works if you consider that you expend just as much energy running 5 miles in a straight direction versus running 5 miles back and forth in a gym.)

With my handy-dandy graphing calculator I produced this diagram of what our power/energy wave (Voltage on the vertical axis) looks like over time (the horizontal axis.) It shows what voltage change occurs in your outlet during 1/60 of a second. The electricity swings in one direction and then smoothly reverses itself.

Our electrical and electronic devices rely on this electricity to be carefully conditioned. Too small a voltage (the graph flattening out), results in brown outs and our equipment stops working. (Kinda like pulling the plug out of the wall.) Too large a voltage (where those wavy lines get taller) and our equipment can be damaged. (Think what might happen if a lightning bolt hit wires connected to your computer.)

But to be honest, it is much more complicated than that. The energy we use relies both on the voltage (I think of this as the level or speed) and the current (I think of this as the number of electrons moving) of the electricity being delivered. Most people (including me) use the water analogy. Voltage corresponds to how fast the water moves and current is how much water is moving.

We POWER our appliances. Both the current and the voltage levels determine how much power we get. There is a simple formula that describes this:

In most texts you will actually see this as:

Current is measured in Amperes, hence the “A”. And like Voltage, the current also varies over time. (Other equations use “I” to designate current.)

So imagine as Voltage swings to its maximum on the curve that Current is zero at that point. That would result in Power ending up being zero. In that case your appliance simply won’t run. So the first challenge after making sure the Voltage and Frequency are correct is to ensure the Current is synchronized with the Voltage in order to result in positive power.

The very first electric “grids” were pretty small and only had a single power plant. Once the utilities began growing, grids required multiple power plants, and utilities had another challenge. All of the plants would need to produce their power in step with each other, ensuring they were adding power to the grid at the same frequency and voltage. If they did not the resulting wave form would change and be somewhat bumpy.

But even if they did achieve the same frequency and voltage, using simple electrical circuits, they must still ensure they continue to run in phase; that is the zero voltage time and peak voltage times must be synchronized.

Here is a diagram demonstrating what happens when two plants (the red and blue lines) didn’t end up in Phase. Notice how it results in decreasing the grid voltage (green line). That green line would cause a brown-out.

So you can guess, with multiple power sources on an interconnected grid starting in 1921 and throughout the 20th century, that utilities had a complicated problem to solve. However, with complete visibility over the sources of power and delivery, it was possible to put the controls in place to ensure all the power sources feeding the grid complemented each other.

However, they still were challenged as they had virtually no control over the demand. DEMAND is us consuming the power.

The matching Demand Problem

I have to confess, that originally I never considered how the grid functions. I was thinking they produce the electricity and it is there for me to use. But I didn’t consider MY ROLE in the stability of the grid. As I turn on my appliances, I consume some of that power.

Here that water analogy starts to work again. Imagine that my power use corresponds to me pumping some water out of a river that is flowing past me. Well that means there is less water for the folks downstream. If enough of us do that at the same time, then the stream will start to lower and eventually dry up.

And that is exactly what happens on the grid!. As we use the power on the grid to run our appliances, the grid power starts to drop (brown-outs). If the utility responds by pumping more energy out, but we all suddenly stop using power… flooding… The voltage on the grid climbs above that 120V.

In fact that brings us to the next grid complication.

              AT ANY INSTANT IN TIME, THE SUPPLY ON THE GRID 
                  MUST MATCH THAT INSTANTANEOUS DEMAND   

Throughout the 20th century, pretty much the utility had complete control over the supply either through its own facilities or through the agreements they have with power providers. (In California public utilities can only own nuclear and large hydro energy plant. All other power they are required to source from 3rd parties.) So you can imagine what a challenge it is to increase or decrease power on the grid to match precisely a fluctuating demand that you have no control over.

Luckily with millions of us, statistically the hourly demand could be somewhat accurately projected. Heat waves and sudden failures in supply could still cause unexpected excursions. But the utility does a pretty good job of keeping the balance and achieving their uptime goals.

It is quite a balancing act that is supported by studying historical use patterns. But now we move from the 20th century realities to the 21st century expectations.

So let’s throw some more variables into the mix and see what happens.

Renewable energy causes problems

Perhaps you can already guess why I say Renewable energy causes problems from the hints I gave above. Utilities pretty much had control over the electricity supply and they depended on predictability of demand patterns to provide the reliable, high quality power and energy we have come to expect from them. The 21st century is going to not only introduce a change in demand intensity, but because we are introducing renewables quickly as a Distributed Resource Energy (DRE), the supply-side controls and reliability are being compromised.

The nexus of Distributed Resource Energy and Renewable Energy is the supply challenge posed in the 21st century.

With DRE, the utility no longer has control of the supply. In fact, it has little visibility of when the energy comes online or drops off. And the source of Renewable Energy, even if they were centralized, are uncontrolled. The sun shines at specific hours, but the clouds control its intensity. Weather impacts both solar and wind supply. And unlike when one power plant has an interruption, when a neighborhood suddenly is darkened by a storm front, every home’s solar system will curtail production of electricity.

What's the big deal?

So hopefully I left you with an appreciation of how challenging it is to deliver reliable, high quality electric power to us. We take it for granted, but indeed it is a technological marvel.

In this post, I describe how DRE and Renewables will force a change in the way we achieve continuing to have a stable grid. In a previous post (Electrify Everything) I covered my experience that demonstrates how peaks will shift as electric vehicles become the norm. This shift in intensity too will play a large role in determining what grid changes are necessary.

21st century solutions for 21st century challenges

We assume the way things worked in the past is how they will work going forward. But moving from the 20th century needs and constraints into the 21st century needs and opportunities cranks up the degree of difficulty of continuing to accomplish maintaining that 99.999% uptime mark. Changes are already occurring that require fundamental reconsideration of how the grid will need to function.

And that leads us to the target of my next post, The Grid. And more specifically my thoughts about the distribution grid, the 21st century pressures on it, and how it is likely to transform over the next decade.

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At the end of this past summer, our local power utility. Pacific Gas and Electric (PG&E), held an Innovation Day. During that all-day event they identified the challenges the next generation energy grid will present and the problems the utility will face in making the transition.

They documented 70 problem statements and asked innovators to submit solutions. The problems addressed the electric grid, the natural gas infrastructure, and the new power requirements that electrification poses for previous fossil-fueled energy consumers.

A group of us were particularly interested in the problems that focused on the electric grid and expanded electric use. We decided to develop a solution that addressed a number of the utility’s stated problems.

The focus was on transitioning the electric grid from its existing centralized design instead to a Distributed Energy Resource (DER) design. Now we have to admit that DER is not a new concept. It has been around for many years and most recently has become more important as the cost of solar, wind, and consumer energy storage been drops. This has allowed an increasing number of utility customers to install solar and storage solutions on their buildings. PG&E recognizes this trend and that its future depends on incorporating DER into its product portfolio.

Over the past 10 years we have seen the cost of installed residential solar drop 65% as the cost of the equipment dropped 85%. This has been driven by manufacturing efficiencies that result from increased volumes. We see a similar trend occurring with battery storage. Here both changes in chemistries and the efficiencies of volume production have driven the cost of stationary electric storage down. These rapid changes result from the rapidly growing electric vehicle market where battery sales have been increasing at 12%/year. This trend of cost and price reduction shows little sign of slowing down.

PG&E has a process called Integrated Grid Planning (IGP) that has remained virtually unchanged for the past 40 years in a period of minimal load growth. Power flowed in one direction. Expecting a 70% increase in electric load over the next 20 years, the utility needs to increase capacity while at the same time find ways to deliver on its promise to provide a net zero grid by 2040.

So, what does this mean? It suggests that DER will present a large capacity to augment the electric grid and help utilities achieve their goals.

Why Transition to Distributed Energy

In a previous post about Electrify Everything I had the epiphany that the EVs we have been driving will become the major consumer of electric energy. Granted EVs are much more efficient (about 3X) than fossil-fueled vehicles. But adjusting for the simpler design that the EV offers, that gallon of gasoline still carries about 30 times as much energy as the same weight in batteries. We consume LOT OF ENERGY to run our vehicles.

From my personal example, provided in Electrify Everything, I estimated that we will reduce the amount of energy we consume by 60% as we electrify our transportation and the appliances that provide heat by burning fuel. However, the electric energy replacing those fossil-fueled systems will exceed the electric energy that we use in our buildings today. This suggests that the electric grid will need to handle peaks exceeding two times their current design and that likely the loads will shift in time.

That latter thought, that demand for electric power will shift in time, is significant. During the summer at the beginning of this century the peak load period was late afternoon as air conditioners began to tax the grid. That has changed dramatically today resulting from the rapid adoption of residential and commercial solar. Now the high demand period is shifting to the evening hours. Several times a year, California ISO actually has a surplus of power resulting from the solar, the DER, installations during what used to be the highest demand period.

If we look at the pie chart below from the US Energy Institute, we quickly see the impact electrifying our transportation sector will have on the challenges for the electric grid. This is just one of the examples of how the load will shift in time.

Transportation accounts for 41% of our energy demand. Now imagine what the load might look like if we begin fueling our vehicles at home. When a large portion of California’s energy was supplied by nuclear plants which have minimal capacity to change output, there was a surplus of power available after midnight. But today, our most common surpluses are when the sun is brightest. But most vehicles are either in use or parked at work during this time. There is a clear disconnect between the time that energy is available and when it is most needed.

20 years ago, the primary method of storing energy to address the discontinuity between the time when energy supply was available and demand needed it, was by storing water at higher elevations. During periods of excess supply, water was pumped uphill. During periods of excess demand, the water flowed down through generators. This pumped-hydro has the ability to generate 3,960 MW as long as the water lasts. But the peak need in California in 2022 was 52,061 MW., well surpassing that pumped-hydro capacity.

California cars get the best mileage in the nation at 31 mpg. And we sell about 38,000,000 gallons of gasoline per day. That suggests that Californians drive approximately 1,178 million miles a day. If those all are exchanged for EVs getting 4miles/kWh we would need 295,000MWh of electricity delivered each day to fuel vehicles. With the California driver covering and average of 34 miles, it will take almost 5 hours on level 2 for them to recharge. If everyone recharged at the same time, that would demand 58,900MW from the grid. We double our peak as we electrify our travel.

That means we need both twice the supply we have today and twice the transmission capacity (larger wires and transformers) to deliver that electricity than exists today. So the question is not just whether we have the capacity to generate the electricity, but rather do we have a realistic way to deliver it were we to continue to use a centralized model.

Below, I picked a day this year. Not summer, not winter, but near the equinox to demonstrate the California’s sources of energy.

Renewables today represent the lion’s share of our energy source. But much like nuclear, there is little control over when the supply is generated. With over 17,700MW of renewables in the state, where 15,000MW of it is installed rooftop solar, it is clear this growing DER resource should be both a source of the electric energy we need and a solution to the distribution infrastructure problems.

Looking for a solution to harness DER

In my next post, I plan to describe the Scalablepower SmartStor solution that we submitted to PG&E. It does not focus on expanding solar, but rather how local storage and control of demand can be managed such that it provides benefit to the local user as well as the utility grid.

Hey, I’m not a purist - there are things that my friends know I do that simply cannot be reconciled with wanting to reduce my GHGs. So it might be important for all of us to recognize we can’t stop producing GHGs (unless we wanted to stop breathing), but we all could find ways to reduce the amount of energy we employ and rely on more renewable sources.

In 2006, besides recycling and diet changes, we invested in our first solar installation. It was a learning experience.

We selected the most efficient system that we could get and installed 2.5 kW of solar on our then home in Silicon Valley. At the time I was blown away with the check for about $80 we received from Pacific Gas and Electric each year. No electric bills and cash to boot. We were on something called the E9 schedule which rewarded us for having installed a solar system.

After a couple years, it occurred to me that this arrangement didn’t make any sense. How could PG&E afford to send me money for my energy and provide a service to me at the same time. They were both making sure that I didn’t run out of power and if I produced too much that they would essentially deal with storing it for me.

History has proven that indeed PG&E CAN’T afford to do that for everyone! Consequently over the past 17 years, the tariffs have consistently been changing in order to balance the need of incentivizing all of us to participate in collecting energy. while not rely on the utility paying retail prices for what normally they could buy at wholesale.

I also learned from that experience that I should never have paid for the highest performance panels and that just having panels did not make us any more resilient to power outages.

The only reason to get the highest performance panels is if you have a limited amount of space to install them. Well in a home with over 2000 sqft of roof, we certainly had plenty of space for panels. Getting panels with a lower yield and a much lower cost per kW would have made more sense.

And as a university-educated physicist, I should have been able to recognize that the power my panels produced at any instant in time (which varies constantly depending access to the sun) all has to be consumed precisely by my home. We had not installed batteries on that system. The only place the surplus from that system could go would be back to the grid. (If the power has no place to go, the voltage would rise and we damage TVs, computers, heating system,; whatever was plugged in.) Whenever the grid went down, the solar system automatically turned itself off.

OK, so here we are in 2023, 17 years later and quite a bit more informed. Our current home in SF North Bay has 6.7 kW of solar and 12.5kWh of battery storage. As mentioned in a previous post, both our cars are electric, our hot water and HVAC systems are heat pumps, the kitchen is all electric, and even our garden equipment is plugin. We made all of these changes after we had re-insulated the home in order to reduce the energy we use.

Now I am questioning if this was a great move. Are we using less energy? Is this costing us less, or is it costing us more? The later question popped up when last November we received a bill from the utility for over $600. That bill (which all solar-installed customers learn about) is the same annual bill which on my first system sent me the $80 check. It is the true-up bill.

I won’t go into why the bill looks like that. Though I can say I spent a lot of spreadsheet hours loading data in order to figure out how it was possible that we owed that. (It was possible.) But the exercise gave me an opportunity to compare how we used energy 15 years ago and how we use it today.

This leads us to the newest set of surprises.

We use a lot more electricity than we did in the past (about 3 times as much),
but we use about 1/3 the energy that we did in the past.

Our home in Silicon Valley averaged about 11kWh of electric consumption per day. This varied dramatically from day to day, but if you take the entire year’s consumption and divide it by 365, 11kWh is the result.

I was devastated when I completed the same calculation for our current home. After converting to LED lights, wrapping the outside of the home with between R12 and R20 insulation over the existing insulated structure, eliminating all thermal bridges, and replacing all the windows with high performance replacements, I expected to reduce the energy need well below the Silicon Valley home. After all, that Silicon Valley home had 100 linear feet of floor to ceiling window walls.

When I did the same electricity consumption calculation for the current home, adding both the energy we collected through our solar panels and the net electric energy provided to us by PG&E, I found we averaged 33 kWh/day. WOW!!! I had no idea!

How can it be explained?

It is amazing how little we think about the energy content and the volume of fossil fuels we use in our lives. I went back and pulled all the bills from this current home before the full electrification went in place. In that case we had natural gas water heaters and space heating; and we had gasoline powered cars.

Before the home was insulated, in a year’s time we consumed 548 therms. One therm of natural gas is equivalent to 29.3 kWh. Our natural gas consumption meant before electrification we were burning 44kWh/day of natural gas.

Then I considered the cars that we replaced. OK, I don’t have bills for them. We don’t think much about it as we pump the fuel at the station. But I can develop an estimate (remember, trained as a physicist). On average we drive 15,000/year. We are pretty conservative drivers - so our cars averaged around 45 mpg. In round numbers that is 334 gallons of gasoline a year that we burned. One gallon of gas contains roughly 33.7 kWh. That means our gas cars were burning an average of 31kWh/day.

So included in our 33 kWh we are absorbing the 31 kWh/day of driving and 44 kWh/day of heating for the house and water. The electric utility records from before the installation of our first heat pumps has been lost. But if we simply use the values from our previous, less efficient home of 11kWh as the base case, then we are comparing 33kWh to pre-electrification energy consumption of 86 kWh.

After electrification of our household, we are using 62% less energy today than when we were relying on fossil fuels as a heat and mobility source.

This 62% is an interesting number. In the book “Electrify:An Optimist’s Playbook for Our Clean Energy Future” by Saul Griffith, he maintains that by electrifying everything we can reduce our consumption of primary energy by 60%.

OK, here we are! We electrified one home and household and achieved a 62% reduction. Right On!

Additional Thoughts - are we ready?

This post does not explore the concern that the existing grid does not have sufficient capacity. Today I believe PG&E has a capacity to deliver near 94 million kWh/day.

PG&E has 4,800,000 residential accounts. If they exchange their gas cars for EVs and average the same 15,000 miles per year of travel as our household does, that would require 50 million kWh of electricity each day to power their electric cars.

On the home front, heat pumps in California run about 3.5 time more efficiently than gas heaters. Using our home as an example, we can multiply out that the 60% of PG&E customers converting from natural gas to heat pumps will represent an additional 36 million kWh/day of capacity.

There is a challenge ahead of us.

NOTE: A separate topic is the operational and lifetime cost difference between fossil fuels and electric options. This might be a future post or you can watch my short video as I explore this and why electrification is more valuable than meets the eye.

What’s next - dig in and see if we can find a way to get UN-confused.

I have this really nifty app that Sonnen (the Shell company) sent me that explains how my solar and battery system are working. I’ve been trying to see how I can increase our self-sufficiency. (As one REAL critic explained, self-sufficiency is not the only goal one might try to achieve. But that discussion is for another post.)

But as I review the results today I was really confused.

How can I have generated 15.7kWh so far today, and I have only consumed 16.9kWh, be just 53% self-sufficient? And why is there only 8.9kWh applied to my needs (energy world calls needs, demand)?

Looking at this diagram above, we can see the battery is discharging (the green line) throughout the evening. In my attempts to increase my self sufficiency, I have configured the battery to discharge from 4 PM (when the premium utility rates kick in) until 10:30 AM (when the sun usually starts reaching my solar panels.) With the goal through that period of minimizing grid imports, the battery is configured to allow discharge all the way to 30% while the grid is available.

As you follow the green line, today it only discharged to 40% until solar energy began to be collected (the yellow line). At that point the battery began to refill. The battery is a 12.5kWh pack, so with 60% discharged it needs 7.5kWh of energy to be fill back up. The solar array is just under 6.7kW, but this is late October, so that peak we see at 11:45 is just at 4.2kW. Any surplus solar energy not necessary to power the house begins to fill the battery.

The dog and I decided to find a new place to hike this morning and went for a drive. I kinda got lost, so the battery in the EV drained for 48 miles. The way I drive, that equates to about 12kWh of energy. When we returned home we plugged in the car to take advantage of the solar power available.

We see the demand (the blue line) changing dramatically as soon as I plug the car in. But the car doesn’t know about the limits of the solar array and so it begins to pull 7.7kW of energy to refill its battery. Over the time it takes to refill the car battery, the solar array averaged about 2.8kW, so the grid needs to supplement the supply to meet the demand.

Now I am starting to get a hint at why the self-sufficiency is so low. It has to do with the definition of consumption.

SolarEnergy - BatteryRecharge + GridEnergy = Consumption

And yes, the system does measure consumption directly. The ah-ha for me is that recharging the battery is not consumption, nor is the discharge of it supply. The battery’s machinations are nothing except a shift of the energy supply. The battery energy doesn’t care whether it sources from the solar or from grid supply. So it simply does NOT enter into the calculation of Self Sufficiency. But it does drain the supply that is used to calculate self sufficiency since that energy was NOT available to satisfy demand!

Let’s check and see if the numbers confirm this epiphany.

OK, up till now today (about 2PM) The house has been using around 300W/hr (5.2kWh/14hr) and the car took 12kWh. Adding those together (17.2kWh), we are pretty darned close to the 16.9kWh the app has reported. And we know that the car was going to drain at least 7.9kWh from the grid to supplement the solar. That’s where we see most of that grid contribution of 8kWh.

WOW! this all matches well with the self consumption reported.

The curious part to watch for the remainder of the day, up till midnight, is how the Self Sufficiency increases. We should have a little more demand that the battery will continue to offset after we reach 4PM and the battery is allowed to discharge.

But in any case, the 7.9 kWh supplement required to charge the car will keep self sufficiency from reaching to 100%, That is because regardless of the past experience, the battery is not allowed to discharge in excess of the realtime demand.
(It can never catch up. Kinda like the 5 year old can never become older than the 7 year old regardless how long they each live.)

OK, so now I stand Un-confused.

I am at that age of retirement and bored with the thought of not working everyday. (I bet there are a lot of people like that in the world. ) I enjoy thinking. I enjoy making things work. I have to admit I don’t enjoy focusing on just one thing at a time. (That might explain my tendency to lose jobs where people insist that focus is necessary in order to get things done.)

If I listed the positions and jobs I have had, you might consider that I had no consistent career. (Hmmm lack of focus…) But in reality every job had one thing in common. I was a system designer. I kind of think that to be a system designer, and you want to design really useful systems, that you should not be dedicated to focusing. You have see everything around you and how it can fit together.

I found focusing is a bit like looking at the world with just one eye. You can se the things in front of you, but what about the stuff on the other side of your nose? And, unless you are moving around a lot, how far away are things.

So maybe I don’t focus nor do I stay still a lot! I want to see everything, see how far away it all is, and basically see how it all fits together.

Today I am interested in determining how we can reconfigure our lives so that we those things we enjoy while live within the budget this planet has provided us. Weird… Here I am having lived in 2 separate centuries. I find we have 20th century systems trying to solve 21st century problems. It might be possible… but I really doubt it.

The reason for this substack is to explore thinking, ideas, observations, and see if anyone else REALLY wants to criticize those thoughts - and set me straight.

And if I don’t focus on environmental issues, you will have to get over it.

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