How feasible would it to set up, your presumable hot water heater, to only run when there is an excess of solar energy, rather then all the time? Although this could leave you with cold water in the morning, maybe just restrict the lower element, so the upper can still heat a smaller amount of water.

In other word, without resorting to batteries and other means of storing energy, is there a way we can automatically consume the excess PV energy when it is available, rather then sell it to the grid at a low price, only to buy it back later for double.

I have my own selfish reasons for asking, there is a housing development going in the next town over, that we may buy into in two years time. The houses are HERS 55 rated (24" stud spacing, 6" insulation + R12 sheathing, triple glazing, etc), all electric, and PV ready. I expect at some point, that National Grid will push a similar plan to yours, so I'm curious what options exist to balance things short of battery, or a Tesla.