Super awesome and would totally buy it, but
I'll add this to the list of awesome ideas/invention that will never pay itself out. Would make sense to get this for people that are slightly above middle class and higher, otherwise, the cost / saving ratio does not justify it, at least not for decades.
We'll see where the technology will be in 15 years on this. But even if it was affordable, somewhere, someone would impose a hidden tax or fee, or delay the application of that technology. Understand that all these invention that save all this power and energy will NEVER be affordable over night to the general public, it would cause a catastrophic impact to the economy. Every major invention has to slowly integrate itself within our system for that reason.
Can you imagine if tomorrow half the population didn't need to go fill up on gas, or need to have a hydro account or hydro's services, etc etc.