Balcony solar on the garden shed
I’ve been thinking about getting some solar for a while. In Germany, “balcony solar” has gotten very popular in recent years - for a good reason: you can offset a ton of your power use with reasonably priced hardware, and grid power is expensive here, so a setup re-pays the investment after only a year or two in many cases. And within certain limitations it’s all DIY doable, with no permits or electrician work necessary, the inverters are plug-in via a normal Schuko wall outlet.
In my old apartment, the balcony was facing north-east and there was a ton of tree shade, so the installation made no sense. But as soon as we moved into the new house, I started planning a setup on one of the garden sheds. And this past weekend, it’s finally complete:
Hardware I went with:
- Zendure SolarFlow 800 Pro - all-in-one 2,6 kWp inverter + 1,92 kWh built-in storage, with up to 800 W of grid output (max for a permit-less “balcony solar” install)
- 4x 500 Wp Sonnex bifacial modules (total of 2 kWp - again, maximum for permit-less)
- Shingle roof mount kit + replacement metal shingles for where the mounting hooks come through (surprisingly expensive, but basically adult Lego and solid af, so probably good investment there)
- Some 45-ish meters of 6mm^2 solar cable, a bunch of MC4 crimped connectors, and an industrial amount of zip ties
The Zendure system is awesome. Super easy to set up, and integrated storage is great. It’s also extendable - could buy up to 4 extra packs with 1,92 kWh each and stack them. Thinking about actually adding one.
Of course the whole thing is integrated into Home Assistant. Works pretty much out of the box, even reads the existing HA electricity meter sensor and makes sure to only feed as much into the grid as necessary to keep the grid import at zero (“Nulleinspeisung”). Any over-production beyond that goes into the battery, and is then used up over night. Very neat imo.
First day usage stats. Top chart shows self-utilized solar production (yellow), battery charging (pink), and then battery use (teal).
Blue and dark blue are the grid imports from our two meters - not fully zero, since one meter is completely separate from the system, and the other also occasionally sees higher peak loads than the 800W the system can provide, so needs some extra grid power to compensate.
But 47% autonomy on a very overcast day - I’ll take that. And there was some over-production in the afternoon when the battery was already full even - which is why I’m thinking about extending it right from the start :)