Every October, I’ve been writing an annual update blog post to keep readers up to date on how my solar array is working out. Here’s yet another, with some interesting details.
The graph above compares the production for each month of the year since the full solar array came online. You can see here that production was lower almost every month compared to the prior year, although a little bit of catching up was done in August and September. And, of course, last June is pretty hard to beat! Total production for my 2015-16 solar year was 14,275 kWh, compared to 15,526 kWh in 2014-15. The predicted average is 14,752 kWh, so it’s not really doing too bad.
In last year’s update I noted that my energy bank, which accumulates during the summer when I produce more energy than I use, peaked on October 7th at 3,880 kWh and lasted until January 2nd. This time, it peaked on October 5th at 3,827 kWh and lasted until December 30th, which is remarkably similar. For the upcoming season, the situation will be much different, however.
Those of you who have been following this blog for some time may notice a change in pronouns; I used to refer to “our” solar array, but now call it “mine”. Earlier this year, Trish and I split up, on good terms. She may still post on this blog from time to time, but I have kept the house and solar array, so I’ll continue to write about that. A benefit of her moving out, though, is that my energy usage has decreased (mostly from now only having one electric car instead of two); this means my banked energy through the summer is much higher than it was the prior year, and will carry over longer into the winter as a result. As of mid-October, it looks like the peak was similar, on October 6th, but at that time it was at 4,733 kWh — about 900 kWh higher than the prior years. Since my usage will continue to be lower, this should last somewhat longer into the winter than previously, perhaps through the end of January. Only time will tell!
Unfortunately, we were unable to convince the Washington State Legislature to pass changes to the law regarding production incentives, which I had posted about in January. As a result, our utility, Puget Sound Energy, had to reduce production incentive payments in order to not exceed their state-defined limit on total payouts, due to the large number of solar installations recently. Luckily the reduction for 2016’s payout was pretty small, as I had predicted, but it will get worse as the years go on if we don’t get a change to the legislation.
Despite that, as of the end of September, I will now forever be cashflow-positive on my solar installation! In total, I have received $29,104 in incentives and saved $4,430 on my power bill as a result of having the solar array. I have paid out a total of $30,692 in loan payments and other costs. So today, I have $2,842 that I would not have if I didn’t have a solar array — and every year from now on, that number will increase,as you can see in the following graph.
By the way, the three big spikes you can see in that graph are:
- Receipt of the federal tax credit from the first phase, followed by the spending of that on the second phase
- Receipt of the federal tax credit from the second phase, followed by the paying down of a loan
- Receipt of the 2014-15 production incentive check, followed by some paying down of a loan
The last major increase is the 2015-16 production incentive check. Since I have refinanced and rolled my solar loan into my mortgage, and the rate is incredibly low, I’m no longer choosing to pay down the loan with the incentives. You may also notice in the graph that I am predicting decreases in the incentive payment amounts until they end in 2020. Nevertheless, the solar array at this point is easily profitable and should continue to be for the rest of its lifetime, which is outstanding! It took just short of three years to get to that point.
You might be interested to know that my total power bill for this 12 month period was $345. This is higher than the prior year, which was $173, due to the production being lower and more car usage, prior to Trish leaving. The household energy usage has actually continued to decrease, even prior to Trish leaving. Here you can see the total energy use for the house and cars for each year ending September 30th:
In fact, the total usage for the house and the cars in 2015 and 2016 is less than the total usage for the house alone in 2012. This is a combination of many factors, including closing off the chimney, switching to LED lighting, and getting a smarter thermostat.
At this point I’m generating almost as much power as I’m using; probably at least 90%, with just me and my pets. If I didn’t have an electric car, the array would be producing over 125% of my electric needs.
Last year I provided a rather complex graph showing my monthly usage and generation since Trish and I bought the house. Here’s an updated version. There’s a lot to see here, so if you’re not a data-hungry person, you can skip over it.
If the trends continue, I expect to see still lower power usage over the next year and reasonable production. I’m hopeful that we can get the state legislature to pass a bill that will prevent our incentives from dropping off as they are predicted to do, but I’m not optimistic about it at this point.
Thanks for following along. Feel free to comment below and let me know if you have any questions.