Off-grid in Laos

The house used to be connected to the public grid. But the local grid was too weak: the voltage dropped below 180 volts, the inverters shut down to protect themselves, and exporting didn’t work. So since 2025 the house has run off-grid – as a pure island system that supplies itself entirely.

Off-grid means: what the roof delivers is all there is. 21.4 kWp are split between the east and west sides, three Growatt inverters work in parallel, and four battery modules hold 41 kWh between them. This battery is the power plant for the night – and it has a lot to carry: air conditioning running flat out and, in the monsoon season, days when hardly any sun gets through.

On sunny days the opposite happens. The battery is already full by mid-morning, and because there is no grid to take the rest, the inverters curtail the modules. The sun would be there – it just has nowhere to go. That is why there is an Antminer S19k Pro in the house: when it runs, it takes the power the full battery can no longer absorb.

Here the MINEOMAT controller runs in island mode. It reads all three inverters and the battery via Solar Assistant and runs the miner in three stages between 1,500 and 2,755 watts. The battery should be full by sunset – that takes priority. And the most important rule is island protection: if the battery drops to 30 per cent, the box stops the miner, well clear of the 20 per cent at which the inverters would shut down. Only from 35 per cent may it start again.

The operator sets the limits: never more than 2,760 watts for the miner, and in the evening it may keep running from the full battery for a while. The box sticks to that. Everything was set up remotely, some 8,700 kilometres from Austria. A second S19k Pro has since been ordered – it arrives in Laos in November.