2025 Energy Retrospective

Julien ARNAUD

Notable events

  • Mid-july, my Mazda MX-30, parked, got totaled by a Tesla driver (obstacle avoidance? go figure...). Replacement is my trusty Twizy. The twizy is not used to go for long drives and is slightly more efficient. 

This is a followup to the 2024 Energy Retrospective.

Overall solar production

Solar production is fairly similar to last year's. We reach 450kWh in June 26 where the maximum was 360kWh August 24. Mostly due to temperatures and intensive use of the air conditionning. The minimum monthly production during winter are now around 140kWh (up from 60kWh last january with solar panel partially installed on the floor instead of the roof).

Key numbers
  • 4.100 kWh (4.1MWh) consummed. down 180kWh from 2024.
    • 520 kWh (0.5MWh) by the car/wallbox. down 400kWh from 2024
    • 900 kWh (0.9MWh) by the sockets of the house. strictly identical
    • 225 kWh (0.2MWh) by the hot water tank. down 75kWh from 2024
    • 907 kWh (0.9MWh) by the heatpump. up 200kWh from 2024
      • 475 kWh (0.5MWh) for heating. down 25kWh from 2024
      • 430 kWh (0.4MWh) for cooling. up 200kWh from 2024
  • 3 580 kWh (3.6MWh) produced. up 800kWh from 2024
  • 1 700 kWh (1.7MWh) injected in the batteries. up 400kWh from 2024
  • 1 300 kWh (1.3MWh) recovered from the batteries. up 200kWh from 2024
  • 1 020 kWh (1.0MWh) drawn from the grid. down 800kWh from 2024
  • 120 kWh (0.1MWh) accidentally re-injected in the grid. strictly identical
  • 75% overall self-sufficiency over the whole year. up 17% from 2024
  • 24 kWh maximum daily production during the longest day of the year. identical
  • 10 kWh maximum daily production during the shortest day of the year. identical
Blue is the grid, green is battery discharge, pink is battery charge, purple in re-injection to the grid, orange is direct solar consumption.
Cooktop is not properly tracked yet
House's batteries SoC min/max daily. Anything above 100% and below 20% are monitoring anomalies.

Hot water production

As a reminder, it uses a 20~70W fluid circulation pump with two large thermal solar panels and a 2.6kW backup resistive element.

Weekly

Heating

Seeing how last winter's strategy of cutting of the heatpump at night worked, I did the same this year. With a reserve temperature of about 14°. It only kicked in during the harshest nights at -2°.

The green curve is the outdoor temperature. The three other curves are each floors of the house.
Humidity levels, per floor

We've had some very cold days (for our region) this winter. January 2026 actually. With a 0° average on 24h (and -2° dips), the average power draw of the heatpump was 450W over 24h.

You can take a look at the sizing of the heatpump for initial projections.

Heatpump consumption, weekly.

EV car

A tesla driver crashed into my MX-30 (EV), it was totaled. We can see a blackout until I retrieved my Twizy from a family member. I'm extremely happy to have gotten the Twizy back, since we had two snow days and drifting it on open roads was a treat.

EV Wallbox, weekly

Despite being a very light car with fairly narrow wheels, the Twizy is not efficient at all. Considering the MX-30 is about 1750Kg (the Twizy is only 475Kg), we would expect better efficiency numbers. 

EDF (electricity provider) bill

Energy drawn from the grid, weekly.

This year we had a much more gradual transition from full solar to grid powered in autumn.

Below is our actual billing from the provider. This is our only utility bill, as electricity covers our needs for heating, cooking and transportation. 440€ for the calendar year. Looks like EDF increased the subscriptions fees, because we went from 17€ to 19€ for months with zero power drawn from the grid.

  • Jan: 108€
  • Feb: 63€
  • Mar: 26€
  • Apr: 19€
  • May: 18€
  • Jun: 19€
  • Jul: 19€
  • Aug: 20€
  • Sep: 20€
  • Oct: 23€
  • Nov: 39€
  • Dec: 79€

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