Electrify Everything
Surprises along the way - Is it valuable?
I have to admit, I have been on a journey to electrify everything for a while. I didn’t realize it at first! What I realized was that we were increasing the amount of Green House Gases in the atmosphere and that I ought to do what I could to not contribute to that.
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.