Sunday, March 26, 2023

Solar Update: It's Not Even April and My Meter Is Running Backward

In my last update on the performance of my solar power system, I had several open questions concerning what to expect during the winter months, and also about what to expect in the new year. Both have been answered in terms that are pretty clear. 

First off, production versus consumption in November continued along the same lines of September and October, though in a somewhat diminished fashion. The system produced 616 kWh against overall consumption of 544 kWh for a ratio of 1.13.

Of that production, I directly consumed 200 kWh, or about 32 percent, directly from solar and exported about 416 kWh to the CenHud grid. The level of production fell from slightly north of 1 mWh in September and 812 kWh in October. 

As you might expect for the season, the trend reversed itself in December and in January. For December I consumed 602 kWh and produced 428 kWh. In January consumption was 592 kWh and production was 396 kWh. And while in both of those months, I consumed more than I produced, they were nevertheless a victory of sorts. I mean who would have expected that I'd produce more than two-thirds of my power from solar during a Hudson Valley winter? 

February reversed the trend once again — I produced 114 percent of what my house consumed that month. And March is on track to repeat that feat, but only higher. As of today, the number is 154 percent.

The explanation is simple. It's been an unusually mild winter, with lots of cold sunny days. Consider the graph below from Dec. 21, the shortest day of the year, when the sun rose at 7:18 AM and set at 4:28 PM. I'd like to show this graph to the doubters who thought I'd never get good solar production in the Northeast.

This brings me to another point about the trend of my power production and consumption for the calendar year. Put simply, production for the full year to date is well ahead of consumption and it's not yet April. As of today, I've produced 1.79 mWh against 1.64 mWh worth of consumption which works out to 109 percent. 

I've been tracking this trend elsewhere via the figures displayed on my net meter. I take a picture of it with my phone and send it on to CenHud every month or so in order to create a reliable record of my consumption and to head off its often inaccurate billing estimates. As luck would have it I took a picture of the meter on Jan. 1 when it was displaying 2104. Today that figure was 1969. That implies that for the calendar year so far I've got a credit of about 135 kWh which given the average price of about 17 cents per watt-hour works out to about $23. 

At first glance that amount isn't much to write home about, but had I consumed the same amount of power without the solar system, I would have owed the power company more than $277 plus delivery fees, which would boost the cost to well above $300. 

I suspect that by the time summer hits that credit will grow considerably. My hope is that it's enough to offset the increase in consumption and cost from running the air conditioner and pool heater.

Another issue has come up: The gas portion of our utility bill remains stubbornly high. I've started wondering if it's worth the effort and investment of replacing the gas cooktop with an electrical induction cooktop. When we remodeled the kitchen last year, we kept the existing gas range in order to keep the project cost under control. Secondly, we're due for a new water heater. I'm thinking tankless electric. 

Meanwhile, there are a few other things I wish I knew: Snow rolls off solar panels really easily and tends to accumulate in greater amounts near the panels than other sections of the roof. The main batch of south-facing panels on the house is mounted above the back deck. At various times of the day and night, we'd hear violent-sounding bumps as sections of snow would melt off and hit the deck or other sections of the roof. The first time times it was a little jarring. Matt Ferrell discussed this and a few other things in his Undecided video series, of which I have become a recent fan. If you're thinking about going solar, you should be a fan too. 

( Graphics are from my SolarEdge dashboard. The sun photo above is by Razvan Dumitrasconiu via Unsplash.)

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