What has kept the non-business users off spot priced contracts? It would seem like a good setup if you have some kind of backup power and own eg solar generatio

What has kept the non-business users off spot priced contracts? It would seem like a good setup if you have some kind of backup power and own eg solar generation. And in a situation like this you could benefit from selling generated power. In some other parts of the world private end-users semi commonly have spot contracts.