Background, we have a home in Eastern Japan with a 12kw solar panel system installed. We are a family of 2 with one of the two staying at home almost always during COVID. The excess (beyond what we use) power generated goes toward the company who built our solar panels, in exchange for building it for free. The house is all-electric. We have an electric car we charge as well with the power which will add to the costs, but I am pretty good about only charging during sunny days. The air conditioner/heater is always on (zenkankuuchou) We are not allowed to install V2H or a solar battery in excess of 1kw, or it will break the contract and saddle us with all sorts of penalties.
I will provide the data below in the hope others find it useful when comparing their own use and doing there own calculations. I did minor rounding to protect private information.
**I also would like to ask if anyone with experience knows how much energy/money I am looking at saving over a year/month if I install a 1kw solar battery system (they are pretty hard to find, but exist,) so I can make a semi-informed decision regarding the ROI.**
FY2022 non-solar energy use (pulling from city grid, cloudy days/nighttime etc) Kwh
May- 350 June 300 July 350 Aug 310 Sept 360 Oct 420 Nov 340 Dec 350 Jan 630 Feb 930 Mar 980 April 712
FY2023 non-solar energy use (pulling from city grid, cloudy days/nighttime etc) Kwh
May- 490 June 310 July 320 Aug 270 Sept 320 Oct 320 Nov 280 Dec 380 Jan 490 Feb 740 Mar 700 April 480
Due to the energy price increases over the year both years were around the same cost per year even though the first year was more energy used. *Total energy bill per year 200000JPY*
by yagerau