Which means what, exactly? Operating your refrigerator is not marginal usage. Heating your house is only marginal usage to the extent that it’s somewhat optional and its cost depends on the weather. It’s certainly not marginal in the sense that people are looking at the price tag for one hour of heater operating and deciding accordingly.
If you know ahead of time that you are going to use your refrigerator throughout the next 12 months _and_ you want peace of mind, perhaps you shouldn't buy spot electricity for that?
There's a futures market for that. As a retail customer, you probably wouldn't want to use it directly. But companies can offer that as a service for you, and give you a long running contract that they hedge via the futures market.
To the retail customer that looks pretty much like a regular old contract, but with lighter regulation on prices on the backend.
Btw, my comment was meant in the sense that from the point of view of the market, one individual household's electricity consumption wouldn't move prices too much. Thus it's at the margin.
