Water heater power usually use gas or electric. Did you know there are also bio energy that can used as their fuel. The energy come from cow poop. With proper extraction and fermentation this poop has a lot energy like atom bomb.
The research compiled on this tankless water heater reviews page. You can get the journal with downloading the pdf file there.
More information for this can be found on another blog, like this best tankless water heater and many more on the net.
This can be helpful and reduce huge cost of electricity and gas bill for everybody. You can have a multi point tankless water heater in the house without worrying your bills anymore