The chart above shows the Greeny Flat’s energy use and production for last week. And the little box shows that on Sunday, Oct 19th, we used 4.18kWh of electricity and we produced 17.76kWh. That’s a production of just over 4 TIMES as much as we used!
But then the next two days were cloudy and cold so our production dropped way off. And on Tuesday, Oct 21st, our usage jumped up dramatically. That’s because we had to run the electric booster for the solar hot water system because there wasn’t enough sunlight to heat all the water we needed for the day.
The chart below shows our actual power production and usage for the Sunday. The big green lump is the production from our solar panels. The red line is what we used. The three spikes in the red line correspond to breakfast, lunch, and dinner when we were using electricity to heat our food.
The next chart shows the power production and usage for the worst day last week, Tuesday, Oct 21st. As you can see, our production (the green line) was feeble that day because it was cloudy and rainy all day. And the big red mountain in the evening was due to us running out of hot water, switching on the electric booster on the solar hot water system, and cooking dinner at the same time.
All of the above goes to show just how much energy is used by things that use electricity to make heat. The spikes in the red lines were due to cooking and the big red peak was due to heating water. So, in order to limit the amount of energy that we use, we have to minimise the amount of electricity that we use to heat anything, be it boiling a kettle, making toast, cooking food on the stove, heating water, or heating the air in the house.
The great news is that we just passed the half-way point in our first year of monitoring and so far we have exported (to the grid) over TWO AND A HALF TIMES as much power as we have imported (from the grid).
Check out the table on our RESULTS page for more details and read our next newsletter for thoughts on what we plan to do next.