Solar operations - Metering

UI has installed meters to record both what is generated, and what is consumed.

With solar installations, you both consume an amount of electricity and generate an amount of electricity at the same time. Some solar installations areas are able to get by with one meter. Consumption tries to move the meter forward (as it normally operates), while generating tries to move the meter backwards. If the solar array generates less electricity than what we consume, the meter's pace toward moving forward is reduced. This is what's called "net-metering".

Connecticut is a "net metering" state under Dept of Public Utility Control regulations. At our location, United Illuminating is the delivery agent for electricity. You can buy your electricity from a number of sources (including UI), but the delivery infrastructure (poles, lines, transformers, meters, etc) are owned by UI. It is UI as the delivery agent that carries out all the metering and billing work.

If over a billing period, we generate more than we consume, the "bill" for electricity "use" will be a negative number, and UI's billing system can not properly address that (UI likely has algorithms that monitor usage patterns to detect fraud). Thus, UI requires 2 meters to be installed. (see above photos) Meter A records how much we consume. Meter B records how much we generate. Meter A minus Meter B is what we are billed upon.

Installing the new meters required co-ordination with IDA's workplace, as the power was required to be shutdown to the building. Before UI would install the 2 meters, the City of Derby electrical inspector was required to close-out our permit with an inspection. Before that could happen, some final housekeeping work had to be completed on the DC side of the system on the roof - which was difficult due to weather. Delays, delays.

So, finally after weather improved and final workmanship was completed, we could schedule the City of Derby inspection (which Derby delayed a week due to scheduling conflicts). When the electrical inspection was done, we scheduled to have the meter work done (which UI delayed for a week due to scheduling conflicts). Now with meters in place - we can schedule a witness test of the entire system.