This week we fired up the third inverter and so the full three arrays of our library solar project (click link to read more about our unique Power Purchase Agreement (PPA) with our partners at ReVision Energy). Installed in September, the 144-panel, 37.44 kW solar photo-voltaic system was just big enough to require some unforeseen upgrades — namely the utility company’s replacement of the transformer and pole that feed into (and out of!) the library. We were approved to energize two-thirds of the system in April before that work was completed, but it wasn’t until the transformer replacement this past Monday that we had the go-ahead to energize the full system, and just in time for the summer solstice.
We’re in peak solar season right now, with the longest sunlight days of the year and a great recent run of clear days. In fact, on its first day of full operation this week, our system produced 254.5 kilowatt hours (kWh) of electricity — which would meet about half the monthly average electricity consumption for a Maine household. Yes, we made more electricity on one day than you and your family likely use in two weeks. The excess electricity that we produce during these peak months earns us a credit from the utility company which will be applied in our favor during the less productive times of the year. Over the course of the year, we expect the system to generate about 80% of the library’s total annual electricity usage.
The image below shows you the system production for May, when only two-thirds of the system was up and running. Production in May totaled 3,529 kWh, while electricity use in the library was only 3,040 kWh. Welcome solar summer!