How Genie knows the home has surplus

Every decision Genie makes comes down to a comparison: are the panels making more than the home is using right now? If the answer is yes, there is surplus, and Genie may draw on it. If the answer is no, Genie waits. There is no in-between.

The question Genie asks

A solar home has power flowing in from the roof and power flowing out to the lights, the fridge, the heat pump, and whatever else is switched on. The difference between those flows is what Genie cares about. When the roof is ahead, the difference is surplus. When the house is ahead, there is no surplus, and the gap is being covered by the grid or by whatever else the home has.

Genie watches that flow continuously. It is not reading a weather service or a calendar. It is reading the home, and it responds to what the home is doing rather than to what a model expected it to do. The precise way it takes that reading, and which home setups it can read, will be part of the full specifications published before anyone confirms a place.

Home first, by construction

The rule that Genie draws only from surplus is enforced in the machine itself, not in fine print. That matters because the home's own demand is not steady. An oven preheats, a car plugs in, a cloud crosses the sun. Each of those shrinks the margin, sometimes to nothing, in a moment.

When that happens Genie backs off. It does not negotiate, it does not finish the current step first, and it does not dip into the grid to cover the difference. The home is served first, always. Then, when the margin reopens, Genie resumes.

Why not a forecast

A forecast would let Genie plan a day's work in advance, and it would also let Genie be wrong. A machine working from a forecast would sometimes draw when the surplus had already gone, which means drawing from the grid, which is the thing Genie is built never to do.

So Genie works from the live reading. It is the less clever design and the more honest design, and Element 31 has chosen it on purpose. The cost of honesty is that Genie's work is bursty: it follows the sun and the household moment to moment, and a cloudy afternoon with the washing machine running produces very little. Genie is designed to accept that trade without complaint.

What the app shows

The household does not have to trust any of this on faith. The app shows energy used, which is to say how much surplus Genie actually drew, alongside work performed, work sold, and money owed. On a day when the home kept most of its own power, the energy figure is low, and the app shows it low.

That is the whole point of the display. It is a record of what happened, not a projection of what might. A quiet day is shown as a quiet day. More on the sequence from surplus to payment is in Surplus in, work out, and the appliance's full set of rules is on the principles page.