While we all look at those awesome looking wind turbines and shiny solar panels, let's also give some thought to the simple but the workshorse-like solar water heater. Humble, reliable and useful, the SWH has needed little subsidies and incentives from governments and has been providing hot water and process heat for over three decades all over the world.

SWH have some real benefits. Here's a post explaining the benefits of solar water heaters for India.

"Some of the salient points about solar water heating in India

1. The payback period is less than 4 years.

2. Typically, for an Indian make system with single BIS approved flat plate collector of 2 sq. m area (required for an average household), the current market costs are reported to be in the range of Rs. 15,000-20,000 ($500)

3. Based on the price of electricity and the region in India where it is installed, the savings per year for a typical Indian household through the use of solar water is in the range of Rs. 4000-7000 ($100-175)

4. Solar water heaters last 15-20 years. This implies that beyond the breakeven period of 4 years, you get hot water at no cost at all.

"

How many renewable energy concepts can you name that have payback periods of 4 years with little or no government subsidy?

China has realized the important of solar water heaters, and as a result, over 25 million Chinese households have these on them. Isn't time that the rest of the world followed China in this?

Here is a link that might be useful: Solar Water Heaters