I’ve tried for a number of years to move onto a sustainable energy path. I’ve been driving an electric car since 2018, we’ve been signed up for Portland General Electric’s green energy plan (which costs more) since I was aware of it (10+ years, I think), and we’ve heavily insulated every wall in the house we’ve opened.
On Wednesday, we activated a new 6.8 kWh solar array for the house. It is projected to handle at least 42% of our energy needs. (Actual figure is likely to be 5-10% higher.) The system carries a 25 year warranty, adds to the value of the house, and of course increases our use of sustainable energy.
Given carbon emissions, climate change, and the rest, I’m going to assume we all agree that using sustainable energy sources is good. What I want to talk about then is the financial aspect of this decision.
We have an oak grove in our backyard. We get almost no morning sun to the house as a result. It’s 10 am on a cloudless day in late September as I write this, and our system has generated only .5 kW today. Like 70% of homes in Oregon, we are limited in our sun-powered energy generation because of trees. In fact, my long-time assumption was that this precluded solar panels as a viable option. I was wrong.
The front of the house is exposed to excellent sunshine from roughly noon to 4 PM, enough that we generated 15 kW of power yesterday (our first full day of use). We’re not going to get 15 kW every day. Winter is coming, some days are cloudy in the afternoon, and so forth. But it’s not nothing, and it’s sufficient that it will likely drop our monthly energy costs considerably.
Those costs average around $180 a month. We’re on a PGE plan that promotes off-peak energy use. That means per kW we pay 7.43 cents for off-peak use (9 PM to 7 AM), 11.9 cents for mid-peak use (7 AM to 5 PM), and 32.8 cents for on-peak (5 PM to 9 PM). Notably, if we go over 1000 kWh for the month, we start to pay 72 cents per kWh. Staying under 1000 kWh makes a big difference.
Do we stay under 1000 kWh? June through October, the answer is typically yes. These are also among the best solar months, so we anticipate doing well here. May and November historically depend on the weather. If they’re rainy or cold, we’ll likely be above 1000 kWh. But climate change likely means we’re going to get more sunny days here in the mid-Willamette Valley, not fewer. So the global bad news actually makes things trend well for us in this case.
The winter months of December through March have outrageous energy use (between 1600 and 2200 kWh). Heating a home, using an indoor dryer (instead of line drying), and just being indoors more all add up. I’m going to be interested to see what I can do this winter to improve on all this. (I suspect I’ll be doing more insulating in the attic.)
Our monthly cost for the solar array is $61 for the first five years. After that, it will jump to $120. The $61 cost will likely by offset by PGE savings, at least during the non-winter months. Even the $120 won’t be onerous comparatively because PGE prices are projected to rise by about 6% annually. You do not want to see the math on what this means for a monthly bill in 20 years. It’s a massive monthly cost.
The solar system itself was $37k. It required no money down, and with a loan at a 1.99% interest rate we did not put any down. Helpfully, President Biden (with a hat tip to Senator Manchin) passed the Inflation Reduction Act of 2022. It has almost nothing to do with inflation. Instead, it’s the most important climate action legislation of my lifetime, and it includes a 30% tax credit for new solar systems. That means our cost is only $26k. The system likely improves the home’s value by at least that much, something rather unusual for home improvement projects.
We used Blue Raven Solar for the install, and it was a painless process. If you’re considering a solar install with them, feel free to use me as a referral. You’ll save $500 and I’ll get $500 as well. (Win-win!)