Another busy week, and I completely missed Earth Day. I’ll make this a smaller post and call it good enough for Earth Week. Last year, I did a ten-year solar review, and there isn’t too much new to report.
In 2025, our solar panels have produced 8.3MWh. It looks like our average price per kilowatt hour was $0.28 last year. That’s down a couple of cents from the 30 cents last year. Overall, that means our bill would have been $2324. That’s an oversimplification, because the price changes in some seasons. I just used the AI answer because it’s good enough for these rough estimates.
Many people will have cheaper energy than we do in Rhode Island. Around 90% of our energy comes from natural gas, and the vast majority of that is pumped from Pennsylvania. The only way to control our energy costs is with green sources such as solar and wind. So while no one thinks of RI as a sunny state that would be good for solar, the math works out quite well.
Over the eleven-year lifetime, we’ve generated 98.2MWh. I have a dashboard that says it is worth $16,700, but there is no explanation of how it arrives at that number. It looks like electricity was 17.5 cents per kWh in 2015. With that growing over the years to 30 kWh, we can grab a rough estimate of around 24 cents kWh. If we do 98,200 * $0.24 we get $23,568 of value in that time. We had to pay $16,000 to get them installed. It seems we would have come ahead (as of now) if we had invested the money at around 3.5%.
The financial case doesn’t look great in hindsight. The markets have grown 12% annually. Our panels are still guaranteed for another 14 years, but that alternative universe has a huge head start. I don’t think it will catch up. Still, there’s also the fact that buying solar panels was a forced investment. We could have spent the $16,000 on frivolous stuff with no financial return. Instead, we locked in the savings for a long time and removed temptation from the equation. It’s also great not having to think about energy costs.
Finally, there’s the whole aspect that I’m writing this article for Earth Day. A financial break-even is still a win for Mother Earth.
That’s it for this week—more updates next time.
