We’ve had our home solar energy system for just over six months, and have now experienced both the best and the worst the sun has to offer homeowners.

Our system was installed just before the Summer Solstice in June. During the summer months there were a handful of long and sunny days when our system generated over 50 kWh of energy, which helped us build up a nice bank of solar credits to offset future bills.

In recent weeks, however, our energy production has plunged as we neared the Winter Solstice. In late December, a combination of limited sunlight and snowy weather meant we produced less than 1 kWh of power on six of seven days.

Not surprisingly, our energy production for December declined from the modest results we generated in November. Consequently, we once again had to make a withdrawal from our bank of solar energy credits to minimize our electric bill.

As the new year begins, our stockpile of solar energy credits has been cut in half from its peak after we produced less energy than we used in both November and December. My expectation is that January will also be a poor month for our energy production, especially since some of our weak production days from late December will be included on our January bill. We’ll likely be making another large withdrawal of solar energy credits a month from now.

The good news is that using solar energy credits to offset our actual energy usage last month resulted in another small electric bill for the ROMT family. Our December bill dropped by 70% from a year earlier. While this was the smallest year over year decline we have experienced to date, our bill was still as small as it could be given the rules governing net metering in our state.

Our hope is that minimal bills continue for the next few months while our energy production is constrained by relatively short days and solar panels that are occasionally covered in snow and ice. Since our home solar energy system wasn’t installed until mid-June, we missed out on a couple of months of potentially strong energy production in the late spring of 2017. Because of this, if there’s ever a year when we won’t have enough credits built up to minimize our electric bill all winter long, this will probably be it. In future years, we’d expect to have a larger bank of credits built up heading into the winter, which should help keep our electric bill as low as possible as we continue on our path towards financial independence and early retirement.

For readers who already use solar power, how dramatically has your energy production declined during the winter months?