Thomas shares makes

Virtual Solar/Grid power meters

block diagram

I want to keep counters for how much solar panel energy and grid energy my car uses. I have power meters for the Solar, Grid and the car. The power the rest of the house uses is however unknown, and measured by the grid meter. Determining the car's part of grid and solar power requires some calculations.


I created home assistant template sensors to come up with these power numbers, and added integrators to obtain energy meters. The energy flow plus card can show these in real time on the Home assistant dashboard.

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Solar Matched Electric Heating


A heater power-controlled to consume all excess solar production!

I built a prototype test setup that makes sure every Watt produced by our solar panels is used by an electric heater. It uses an industrial power controller and some code to match the heater's power usage to whatever power is not used by the house.

This would make it possible to maximize our solar self consumption, which is required to get a decent return on your solar investment.

For us, injecting to the electricity grid is giving away power, we have to pay about 6x as much compared to what the utility pays us for returning energy to the grid.

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