Hi everyone,
I would like to share a project/product I developed called the PEEC (PV Electric Energy Converter).
The idea behind the PEEC is simple:
instead of feeding excess solar power back into the grid, the PEEC automatically diverts surplus PV energy to a standard electric boiler or heater.
You can basically think of it as a smart dimmer for a boiler, controlled by your real-time solar surplus.
The system works with:
- Home Assistant
- ESPHome
- Dynamic power control (0–3600W)
- No cloud
- No subscriptions
Home Assistant entities
Features
- Works with existing electric boilers
- Fully configurable through Home Assistant
- Designed to increase solar self-consumption
- Uses thermal storage instead of chemical battery storage
- Supports priority-based automations within Home Assistant
- Can easily be combined with home battery systems using automations
Typical use case
On sunny days, instead of exporting excess solar energy back to the grid, the PEEC converts that surplus into hot water.
This effectively turns a standard boiler into a simple thermal battery — without using chemical energy storage.
The system was originally developed for the Dutch and European residential market, where feed-in tariffs and net metering conditions are rapidly changing.
The goal is not to replace battery storage completely, but to offer a simpler and lower-cost way to increase self-consumption using existing heating systems.
I attached some photos/screenshots below of the hardware and Home Assistant integration.
I would love to hear your thoughts and feedback 
More information (in Dutch 
):