A guy who calls himself “Grant Thompson” used a Fresnel lens from a dismantled old Toshiba projection TV and shows the world on Youtube how his DIY solar concentrator can scorch nearly anything from pennies and concrete to eggs.
In this video Grant shows how he made the wooden frame. Of course, the guy has the tools you need for shaping wood: a saw, a grinder, and proper self-training, so this project is not for everyone. However, you can theoretically have someone doing the woodwork for you and all you need to do then is put the lens in there, after which you can use the 2,000 °F for your own renewable energy projects.
The second video actually scorches stuff. Notice the kids and wife that are playing around, which I consider not to be safe, but with a little training they can handle the DIY solar concentrator, too.
This Treehugger article, quoting Wikipedia, says that “The total solar energy absorbed by Earth’s atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year. In 2002, this was more energy in one hour than the world used in one year.” Which means solar power really is powerful and in the hands of anyone who wishes to use it.
I also made a solar concentrator these days from hundreds of small mirrors (haven’t counted them) that I put on a satellite dish and I’m now having a hard time deciding on a way to harness the power to actually produce electricity with a Peltier unit, (water-cooled) solar cell or steam turbine. And I’m still waiting for a sunnier day. I’ll post the results after something useful comes out of the project.
All I can say right now is that I’ve made this on a partially cloudy sky today: