The real fix here is to have more residential customers either knowing the minute by minute pricing, or paying extra for the privilege of an "unlimited plan" or something.
That could be achieved for example by instead of setting your space heater to "low heat", "Mid heat" or "high heat", you could just hit the "$1/hour of heat", "$2/hour of heat", or "$3/hour of heat" settings. The heater itself can look at the minute by minute pricing to decide how much heat to output, and the user can decide to turn it up if they want to pay.
Electronics to connect to wifi and check a server for pricing cost under a dollar now (ESP8266).
That could be achieved for example by instead of setting your space heater to "low heat", "Mid heat" or "high heat", you could just hit the "$1/hour of heat", "$2/hour of heat", or "$3/hour of heat" settings. The heater itself can look at the minute by minute pricing to decide how much heat to output, and the user can decide to turn it up if they want to pay.
Electronics to connect to wifi and check a server for pricing cost under a dollar now (ESP8266).