6 Answers

Read here>>http://www.nrel.gov/docs/fy04osti/34279.pdf

In some areas, the power company gives rebates for energy saving installations.   Check there, also, in US the IRS gives Energy credit as a tax deduction.  I think it is $2000 worth of credit per yr. per household.  I do not know the formula, I think it is 15% of the cost to purchase, as a tax credit. 

Is good for a hot shower when you’re homeless……….

I have had solar hot water for 20 years.It works for me.But then I am living in a sub-tropical climate.We get plenty of sunshine.

My personal requirements  are much more stringent  than what I have seen on the market. I do not accept component failure or planned obsolescence in the design. It must be simple, goof-proof and work without any modifications or adjustments ever.

That is what I like in an appliance and that is what I produce for my own use...and cannot legally market because it is ruinous to a competitive market, based on planned obsolessence (product failure) in order to continue production of inferrior products. I consider this a form of enslavement binding folk into an endless cycle of work to make money to buy what is necessary to live and replace broken appliances. So to answer your question regarding "investing in"...I suggest you learn how to construct and maintain a simple solar hot water heater for your own use. Learning to do this is a step toward your own freedom...rather than just another pile of confusing junk that no one repairs when it fails.      

It only works when the sun is shining .