They will continue to save money on his monthly power bill, to a lesser extent. They will still have the warm fuzzy feeling that their existence is putting less of a drain on the planet's resources than they otherwise would have. And they may have captured a great deal of surplus value, possibly even enough to pay for the system before these changes are implemented.

In the past 25 years, electricity rates in CA have seen a 3-4x increase. If this continues, then even as some of the advantages drop away, the comparison function (monthly electric bill) will also increase, likely offsetting a lot of lost value.