(This is the latest in an on-going series. Here is Part 1).
As 2019 wraps up, I have some good news and some not-so-good news to report.
First, the good news: in November we got paid $213.32 for the 4 SRECs we generated in the 3rd quarter (July – Sep). These were SRECs 4 – 7. (1 SREC = 1 Megawatt Hour of electricity generated. )
Now, the not-so-good news: in the 4th quarter (Oct – Dec), production dropped off drastically. It took us until Dec 21, 84 days, to generate our 8th SREC.
| Megawatt (SREC) History | |||
| Date | MWh | Days | Cumulative |
| 3/26/2019 | 0 | ||
| 4/21/2019 | 1 | 27 | 27 |
| 5/21/2019 | 2 | 30 | 57 |
| 6/14/2019 | 3 | 24 | 81 |
| 7/6/2019 | 4 | 22 | 103 |
| 7/30/2019 | 5 | 24 | 127 |
| 8/26/2019 | 6 | 27 | 154 |
| 9/28/2019 | 7 | 33 | 187 |
| 12/21/2019 | 8 | 84 | 271 |
From the table above, you can see that the time to generate each of the first 7 SRECs ranged from 22 to 33 days. Comparatively speaking, that 8th SREC took forever.
So, what happened? As mentioned in Part 9, the sun got much lower in the sky and the days got shorter. The oak trees on the south side of my house (some of which are in my neighbor’s yard) did not drop their leaves until early December. Finally, we had a lot of cloudy days. These factors all combined to lower power production greatly. Shown below in picture form:
Through the end of September’s billing period, we had built up a surplus of almost 600 KWh. By the end of November’s billing period we had used it all up, and then some. We owed our electric company about $5 above the $8.22 charge for the meter. So in December, we were billed for all of the electricity we used, less the 255 KWh that we generated. See the chart:
| Date Due | Billing Period | Current Reading | Previous Reading | Metered Usage | Carryover Applied | Accrued Carryover | Amount Owed |
| 5/20/2019 | 3/26 – 4/24 | 99566 | 12 | -446 | 0 | -446 | 8.26 |
| 6/20/2019 | 4/24 – 5/23 | 99265 | 99566 | -300 | 0 | -300 | 8.26 |
| 7/24/2019 | 5/23 – 6/26 | 98971 | 99265 | -295 | 0 | -595 | 8.22 |
| 22-Aug | 6/26 – 7/26 | 98982 | 98971 | 11 | 11 | -584 | 8.22 |
| 9/23/2019 | 7/26 – 8/26 | 99009 | 98982 | 27 | 27 | -557 | 8.22 |
| 10/21/2019 | 8/26 – 9/25 | 98967 | 99009 | -42 | 0 | -599 | 8.22 |
| 11/22/2019 | 9/25 – 10/28 | 99262 | 98967 | 295 | 295 | -304 | 8.22 |
| 12/19/2019 | 10/28 – 11/25 | 99608 | 99262 | 346 | 304 | 0 | 13.21 |
| 1/22/2020 | 11/25 – 12/27 | 83 | 99608 | 475 | 0 | 0 | 65.86 |
In picture form, here is our electricity usage (from our utility) – solar panels went live 3/26. Our billing cycle begins about the 26th of each month (varies slightly).
Agreeing with the Judy Collins’ song, I really don’t like clouds, at all. Here is what cloudy/rainy days in December look like compared to more normal days:
The really short lines around the 1st and the 15th of the month (and a few others) are examples of very low production on cloudy/rainy days. On good days in December, production tops 10 KWh. Compare that to the summer months, where a good day produces over 50 KWh. Big difference!
So what is the take away from this post? When we went live on March 26 our meter read 00012. When they read the meter for our Dec 27 billing, it read 00083. So in 9 months, we have used a net 71 KWh from our utility. In other words we have produced all of the electricity we need to run our house from our solar panels over this 9 month period, less about 3 days. Not too shabby.
As the days get longer and the sun gets higher, here are my predictions for the next 3 months:
- January we will still be in the red, using more than we produce, but less than December. I am hoping we cut the December overage (475 KWh) in half.
- February we will do even better, and I hope we cut the overage in half again.
- That would mean we get billed for about 240 KWh in January and 120 KWh in February, or 360 KWh total.
- In March I expect we will generate a surplus.
I will let you know how it turned out in future posts.
If you enjoy reading these updates, please drop me a note. I will be happy to respond to questions as well.