DIY Solar Water Heating Using Fresnel Lenses

by Tim Fulton on November 29, 2008

The people over at Green Power Science have whipped up this great video showing how to use Fresnel lenses to heat water. As they mention at the end of the video, your lens pointing at a black object will generate as much heat as a black object the same size as the lens, but I imagine this could make for some very interesting solar heating options.

Has anyone experimented with Fresnel lenses or any solar heating projects that could benefit from the ability to concentrate light like this? I’d be interested to hear! Feel free to post in the comments or on the forum.


1 Andrew DeGaust November 19, 2009 at 9:38 pm

Where can I get a fresnal lens to heat my pool? Thanks Andy

2 coulson December 15, 2009 at 12:34 pm

well i hate to tell u this andy but im fourteen and i just recently tried to get a fresnel lense to heat a tea kettle and un fortunatley it does work now im not sure if it would help to apply directly to water to get one big enough to heat a pool im not sure well to answer your question i actually ordered mine over th internet

3 james wilkerson November 5, 2011 at 12:12 pm

the lenses on old projection big screen tvs include a fresnel lens. most times you can get the old tvs for free when they are ready to discard but we have the obligatory responsibility to dispose of the rest. its still MUCH cheaper than buying from suppliers. this is the only way i know to afford to get enough of them to do the trick. maybe you would want to focus them on a type of ‘solar collecter’ and then use a slow moving pump. a 4 by 8 collector should handle 720 gallons by itself.

4 Mark April 17, 2010 at 8:03 am

There are plans in the Utah desert to use Fresnel lenses to heat water and run steam turbines:

The same thing has been done by Joe Holden who is working with a green energy living project:

This heat could also be used to run a sterling engine.

5 Gerald September 26, 2011 at 11:06 am

Rear projection TV’s use a huge fresnel lens to display their picture. If you keep an eye on craigslist under “free stuff”, people are giving away their old ones all the time. Just a thought.

6 prashant kapurkar January 24, 2012 at 3:45 am

i am student of ME(RES) MPUAT, Udaipur, India. i am doing project on fresnel lens concentrated solar water heater cum distillation unit. i need some review literature related to this. can u help me about that.

7 prakash t October 16, 2012 at 12:27 am

i am me student doing project on fresnel lense water heater system plz inform me abt the piping mtrl which can sustain that heat

8 Justin December 6, 2012 at 6:24 pm

Maybe build a black, external, heater tank – using the lens – for the pool. The water would flow into and out of the tank constantly so that the tank doesn’t get hot enough to burn. You could use a passive design that some home water heaters use.

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