Powerbeat Today
Learnings & Assumptions
My learnings as solar owner:
- Daily Production - It’s all about the daily solar production. Even though the monthly and yearly solar production numbers look impressive, what’s important is to charge your car and the home battery for the night on a daily basis. As a result, I started categorizing each day into 0-20 kWh, 20-40 kWh, 40-60 kWh, 60-100 kWh and 100+ kWh buckets.
- Summer Mode vs Winter Mode - A typical solar system in Germany is oversized during the summer and undersized during the winter. So the HEMS needs to run in different modes.
- Usage is not predictable - At least for me, my usage is not predictable. Mainly the car usage (because it’s the biggest consumer), but also smaller energy consumers like the washing machine and so on.
| Day Category | Daily Production | Label |
|---|---|---|
| Too low | < 20 kWh | Red |
| House only | 20+ kWh | Orange |
| House plus | 40+ kWh | Blue |
| Charge car | 60+ kWh | Green |
| Full charge | 100+ kWh | Yellow |
Today
As mentioned above, the daily solar production is key. I’m categorizing each day into 0-20 kWh, 20-40 kWh, 40-60 kWh, 60-100 kWh and 100+ kWh buckets. The main goal of the Today section is to determine which bucket today’s production falls into.
As a reference, the Tesla app is only showing today’s generated kWh:
The mobile app of the SMA inverter even shows a forecast of the next hours and days, but unfortunately the app does not update the forecast data during the day:
A better way to visualize forecasts will be this diagram with a range between best and worst case:
