I agree Invest now and dont say you will do it later, i have oil running underfloor heating and i cant wait to change to somthing else
Looking at a solar / wind immersion option backed up with a wood pellet stove with boiler to back it up and provide space heating in a big open plan area, my big mistake is i did not do something like this from the start.
That said oil was cheaper then and none of these options were as available then. also the water is mixed so it is only going through the floor at 40 degrees, so whats the point heating it any higher?
Just one thing about using electricty as a heat source is the prices seem to go up and up, just like oil and you cant ring around and see who you will get it cheaper from, worth keeping in mind