Remember I installed a passive solar water heater in July, then I gave the electric bill update? Well, here’s the winter update. I’m thankful the installer talked me into installing a relief valve on the roof, intended to open as the temperature drops. Even in our climate, we had a light freeze a few weeks ago that caused the water heater valve to open up and begin dripping. There were icicles on the roof, a rare event (I’ll get pics next time). This is a good thing since it keeps the exposed pipes from bursting. As far as efficiency is concerned, it has dropped drastically in the winter months (Nov. – Feb.) I have trees on the south of my property that block the sun in the winter – not good solar design I’ve discovered. Unfortunately, I wasn’t thinking about passive solar at the time of design, so maybe others can learn from my mistakes. Some sunlight does reach over the trees, but it’s only for about 2-3 hours, not enough to sustain a descent temperature. The installation contractor did warn me about this. As far as the electric bill is concerned, it’s gone down to about $77 since the air conditioning has been off and the heat has been minimal. In fact, the heat hasn’t been on for a week or two. I keep the thermostat on about 66 degrees F and purchased a little space heater to put under my desk if I need it. Since I’m in my office all day, there is no need to heat the rest of the house. That hardly matters when it’s 75 outside like today.