We do a lot with hot water, it's what keeps us sanitary; I'm a plumber, I know what I'm talking about, I have the privilege and the responsibility of delivering that hot water to my community. We use it in a huge variety of applications, from dairy farmers, to wine makers, spas and hotels, to everyday showers. We drink it in our tea and pipe it through our warm floors. And we are all concerned about the energy costs we incur in it's production, be it propane, natural gas or electricity, hydro, coal or wind and solar thermal and photo-voltaic.
  The fact is, many people all across the world do get their hot water for free. A simple black box integrated within or on the structure is a basic example all that's needed, simple but effective. We have similar units available today in the USA that could by lowering our personal and community energy usage by twenty to thirty percent folks, because that's about what percentage dhw takes out of the total building energy budget pie. Could you use a twenty percent energy reduction on your power bill right now? Take that and do a thirty or forty year cost projection with increases included and you'll have tens of thousands of dollars saved. I believe every new home built from now on have passive or active solar thermal water heating integrated to supply 60 to 100 percent of the dhw load.
  I work on a solar water heating collector called the Copper Crickett,  invented and produced in 1985. This percolating system has  no pumps or controls and has been operating flawlessly for thirty plus years, and they are still in operation today.
Let's all "Go Solar Thermal"