Install diary
From quote to commissioning to a battery that runs itself, written as it happened, including the bits that didn't go to plan.
16 June 2026
Tonight the battery ran its first paid grid event: a steady 5.5 kW out for an hour, £4.27 of help to the grid at £1/kWh. It also taught us that once a VPP event starts there's no touching the battery, so we rewired Predbat to prepare for events in advance instead of scrambling during them.
axlevpprevenuehome-assistantpredbat
10 June 2026
Same day as the inverter swap, we joined Axle's virtual power plant in events-only mode. It pays £1/kWh when the grid needs the battery, and because it settles through the smart meter, it earns even though our export still isn't certified.
axlevpprevenuehome-assistantpredbat
10 June 2026
Five days after we found the wrong unit had been fitted, the installer came back and swapped the 6 kW EC 6.0 SP for the EC 8.0 SP we actually ordered. The race against export certification is won.
hardwareinverterinstall
7 June 2026
Three days in, we audited the whole automation stack against what's actually running on the box. Predbat is still in training, but the review caught a subtle automation bug and two settings worth changing before it takes control.
home-assistantpredbatsoftwaretuning
5 June 2026
One day after install, the automation stack is running. Sigenergy, Octopus, Solcast and Predbat are all talking to each other on a £50 Dell.
home-assistantpredbatsoftware
5 June 2026
We paid for a Sigenergy EC 8.0 SP. The installer has just told us the unit fitted is the 6 kW model. Here's what that actually costs us while we wait for the fix.
installhardwaresigenergy
4 June 2026
The system went in on 4 June, and the installers squeezed a 22nd panel onto the roof. We went from 9.98 to 10.45 kWp for free.
installhardware