I was listening today to guys telling me about software (and presumably there is related hardware) that controls electrical usage. It does this by analysing usage and switches geysers and fridges on and off (I assume again as did not get details). They also talk about remote controlling switches.

It works on the db (does not require rewiring a home or installation?) and has a cost per phase coming in. There is a monthly cost to this installation which supposedly can cut your electricity usage from 10 to 30%

Does anybody know anything about this - like how it works, does it work etc?