The Days My Solar Beat the Grid — 2025

Not once in 2025 did the ground-level solar panels in my garden make more electricity across a day than the grid spent running my flat. Not a single day — an honest zero, and worth owning as the baseline.

The strongest month was August, at 24 kWh of sun, but the grid stayed ahead every day of it. The data only starts in August and runs into the dark half of the year, well before the long days that tip the balance — a story the next year would tell very differently.

Two things about the table. The Solar and Grid figures are the win-days only — the sun and the grid on just the days the panels came out ahead. And the grid figure is what actually ran the flat: I set aside the cheap power I bank in the battery for later, since stockpiling is not the mains doing the day's work.

One deliberate exclusion. I set 18 plunge days aside entirely — days when Agile prices fell to zero or below and it made no sense not to gorge on grid. Racing the sun against a grid column I've deliberately inflated would be rigged, so those days count neither way. Of the 144 kWh I pulled in on them, 57 came in plunge half-hours priced at or below zero — free, or paid to me, not by me.

Back then, deciding when to pull from the grid was a manual job. There was no planner yet — each afternoon I read the day-ahead Agile prices and set the charges myself, each one fired by a Home Assistant diary entry acting as the trigger. A daily chore I am glad is long behind me: the charge planner that runs it all now came later.

I was not off-grid, and the year in full keeps it honest: across every fair-race day (plunge days set aside), about 61 kWh of sun against 260 the grid spent running the flat. The panels bided their time — the win-days were coming, just not in these months.

The months, side by side