From Raspberry Pi to micro-grid: ten years at Fruittuin van West

Ten years ago I hung a Raspberry Pi in a meter cabinet in Amsterdam. No product plan, no roadmap — there was a business with a practical problem, and I wanted to solve it with what was at hand: relays and wiring on a wooden panel, a small computer as a web server next to it.

That business is Fruittuin van West: an organic fruit farm on the edge of Amsterdam where a café, a shop, cooling, chicory growing and a home share a single yard. On paper those are five separate consumers. In practice it is one energy system: where the cooling rejects heat, the chicory grows on that residual heat, and what one building has left over, another can use.

You only see that coherence when you have all the layers in your own hands. Over the years I laid the pipework there, built the distribution manifolds, wired the electrics and wrote the controls. Not because it all has to be done by one person, but because the interesting problems sit exactly on the seams: between mechanical and electrical, between installation and software. Whoever works only one layer never sees the seam.

The wooden board with relays has since been replaced. What hangs there now is the Homer EMS: self-designed circuit boards that measure and switch, software that runs entirely locally. The system charges the farm's forklift and golf carts during the cheapest hours of the day — electricity prices differ per hour, and a forklift doesn't care when it charges, as long as it is ready the moment work starts.

The next step is lined up: four hundred solar panels and large batteries, directed by the same system. Then the yard is no longer a collection of grid connections, but a micro-grid that generates, stores and consumes intelligently.

Ten years of daily operation is a stricter test than any demo. Over those years things have broken, been tuned wrongly and been rebuilt — and that is exactly where a system comes from that you dare to trust. Proof instead of promises.