In 2026, the time has finally come: You can buy small batteries with built-in intelligence, allowing you to use significantly more of the solar energy you generate yourself instead of giving it away. And unlike a year ago, they really work well now!  

When the hype about balcony power plants started more than five years ago, I became curious, installed one, and also wrote about it in Elektor. For some time now, it has been possible to feed a maximum of 800 W from balcony power plants into a house or apartment grid via a socket. This can reduce one’s own electricity consumption recorded by the meter. If electricity production exceeds personal consumption, the surplus ends up in the public grid and is simply given away, as there is no feed-in compensation from the electricity supplier. In addition, so-called bidirectional meters, which could record the feed-in to the public grid, are not economical for balcony power plants.

For over a year now, a new trend has been visible. Prev...