Solar PV – 1st Year’s data

Our 4.9kW solar system has performed well we think. Based on 1 year’s data the average figures per day are:

Produced 17.51 kWh

Used 8.26kWh

Sold 15.47kWh

Monthly data can be seen in the following graph.

2014 solar data

January and December figures are high because of Christmas and New Year family social gatherings and entertainment – additional cooking (all electric) and hot water usage.

I will also need to try an identify why in October, so much electricity was used.

As mentioned in a post last year entitled energy use, according to the avarage household electricity use in Japan (so excluding gas energy use) is around 15kWh.

To help in getting our average down to 8.26kWh, the most electricity hungry activities (washing machine and the air-source heat pump for the hot water) are set to work only at night. All other heating is from the wood stove, and cooling in the summer simply by the house insulation (earlier post insulation for more details), and natural air flow.

To help improve the figures for 2015, I hope to work out how to use the hot water system better (all the instructions are in Japanese) to control more closely when and how much water is produced.

Any comments or questions on these results most welcome.


About ifd66

From UK and living in Japan. I am very interested in sustainable development and in general ecology and conservation issues and solutions. Finished building a low impact family house in Shiga, Japan in 2013 and am now focused on using permaculture to develop our plot of land into a more sustainable, productive, and attractive space. My hope is that this blog is useful to those interested in similar issues and way of life.
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