2021 Solar Generation and Energy Use Report
January 20, 2022
I already have some bad news. We were not net zero in 2021. Which means we used more electricity than our solar panels produced in the year. Ugh.
The Details
Total 2021 solar generation: 8,569 kWh
Additional energy we bought from ConEd: 1,304 kWh (used in Jan, Feb, and March)
Total net metering credits remaining at the end of 2021: 831 kWh
Total electric energy use in 2021: 9,042 kWh
Excess energy demand: 473 kWh - BOO!
The excess solar energy we "banked" in the summer was NOT equivelent to the excess energy demand we needed last winter. (We did NOT start 2021 with any credits, even though the panels went up in July 2020.)
Future Net Zero Implications
Is it possible to reduce our electricity consumption by 5%?? I'm optimistic. In our current set up, absolutely! Turn off all the lights!
One caveat: We travelled for all of July 2021. Usually, that would be a high demand energy month due to our mini split air conditioner usage. But we didn't run it at all that month and contributed a lot to our kWh "bank."
Here is the real challenge of our Brooklyn Net Zero Home:
We are making big changes this year which will dramatically change our energy use profile. We are removing natural gas from our home, which currently powers our radiator heat boiler, our gas laundry dryer, our water heater, and our cooking. That is ton of energy usage! 999 therms in 2021 to be exact. NooooOoo!! So much fossil fuel carbon being released into our atmosphere! Terrible.
If you convert 999 therms to kWh, it would be 29,270 kWh. More than THREE TIMES our yearly solar generation! AHHHHH! How do we bridge this gap and have any hope of becoming net zero??
It will not be easy, but I am holding out hope. We plan to switch to all electric appliances: an electric heat pump HVAC system, electric heat pump water heater, heat pump laundry dryer, and an electric induction range. All of these appliances will be significantly more energy efficient than their fossil fuel powered counterparts.
For example: Our current gas water heater takes an estimated 258 therms per year to operate. 258 therms roughly equals 7,559kwh of electricity - nearly our full solar production! Not good. BUT but but but! The electric heat pump water heater of the same size (50 gallon) that we are looking at getting requires only 866 kWh to operate for the year!
The Department of Energy says that water heating accounts for about 20% of a home's energy. In theory, based on this rough math, our new water heater should only consume 10% of our yearly solar energy generation. (Less if we all learn to love cold showers?!)
If our new HVAC system can be similarly efficient (I'll try to run those numbers in a future post), if we reduce our electricity consumption, improve insulation, monitor and optimize our usage, and perhaps even add some cool, new energy generation projects, net zero energy living MIGHT be a possibility!
Follow along to see if we can do it....