Is thermal storage a serious potential contributor to electricity supply flattening?

In managing electricity demand, we are normally concerned with avoiding peak demand, in order to reduce strain on total capacity.
But with intermittent renewables, we also have a potential excess supply problem, when output from wind and solar is high, and demand is low.
Large industrial users are good at taking advantage of such situations, but the domestic sector, where peaky demand is now most prevalent, is not.
In Canada, the electricity supply companies are known to supply large water heaters to domestic consumers. The suppliers control when electricity is used to heat these stores.
Would it be worth doing the same in UK?

• Heat generally has a lower value than electricity per kWh - except in times of potential overgeneration.
•  Creating solar and wind capacity at a level to minimise gas generation rather than to fit within existing capacity constraints would mean long periods of oversupply, requiring storage, supply constraint,or dumping
• ESCO's are now looking at thermal storage as a way to manage renewables, particularly in SME's.

Can it happen at scale before we have a substantially strengthened grid?