The grid is good

We’ve had an Egauge monitor that tracks our home’s solar production on for about a month now. It’s fabulous. For the last week, it’s also been tracking our whole-home electricity usage. Here’s a graph of hourly average power (in kW) from production and consumption.

weekofsolarconsumptionThe solar installers are still adjusting breakers, so output is down, but here are a few things I’ve learned mostly based on our usage.

  • Our house is never using less than 100 watts. We do a pretty good job with power strips, turning off lights, etc. But even at night, even when the refrigerator is cycled off, we’re using around 100 – 200 watts. There are a few things constantly plugged in (battery chargers, sleeping computers, clocks, etc), and I’ll be tracking them down. I’m curious how close to zero watts we can get during the night.
  • Our weekday usage peaks do not match solar production peaks. In the morning, the coffee pot and the hair dryer are running before the sun rises above the trees. The microwave, dishwasher and washing machine often run in the evening on weekdays. On sunny weekdays, we’re sending a lot more energy to the grid than the house is using (since we’re at work). Weekend usage and production peaks match better (see the last to days on the chart). For many reasons, the grid is good.
  • I’m now more obsessed with finding out how much energy things use, and switching them off. The little red line moving in real time on the screen is a great motivator.
  • Our peak demand is probably about 4 kW. The above graph doesn’t show it, because it’s an hourly average, but we hit about 3.5 kW on a very hot weekend day when a number of window air conditioners were running. This is above our peak solar output, which is probably 2.8 kW under optimal conditions. This is also important for a future post I hope to write exploring what it might cost to actually take our house fully off-grid (at least on the electric side).