Awesome project OP! Especially the power comparison. Who would have thought that you can achieve 1kW of energy from 1m2.
On a side note and in a similar direction. Would it be feasible to make a solar concentrator that heats a molten-salt reactor that powers a turbine engine? On a small-ish scale though, such that it'd be achievable as a back-yard reactor?
Could be a semi-viable alternative to solar, perhaps? Though cost-wise, it's probably quite high now that solar-panels and their auxillary hardware have been commoditized so much.
1kw/m^2 is the "standard" rule of thumb for heat energy from solar irradiation. I'm unsure whether OP has done the calculation (in which case, credit to a well built system) or simply cited the standard rule.
There are some large Stirling engines out there that operate on hot oil. With a large diameter piston, quite a bit of torque can be generated with even small ∆T. Oil can be heated as with traditional solar water heaters (i.e., with no concentration), though concentration doesn't hurt.
My undergrad senior year thesis project was exactly this, back in 2011 - to use a solar concentrator to generate electricity. When we started the project, we thought the economics were cheaper than solar PV. At the end of the year, solar PV had already halved in price (this was when Germany and China were doing subsidy wars on solar).
Solar concentrator electricity must be super expensive compared to PV by now.
A 15cm x 15cm mirror used in this project cost 1€.
That's 48€/m2, I couldn't find a photovoltaic panel at that price.
Add to that:
- photovoltaic efficiency is about 20%, while such mirrors reflect 90% of the energy
- photovoltaic panels have an average lifespan of 20 years, while mirrors do not wear out.
Anyway, we're comparing apples and oranges, because we have to add the mechanical installations, which are very different depending on the specific application.
I'm not against photovoltaic in general, I just think that for some applications there are some interesting alternatives.
Which would make the cost of each mirror higher, right? Additional processing will naturally increase the cost per unit.
By the way, super cool project and thank you for sharing. My experiments with concentrating sun power when I was a child were directly related to the spontaneous combustion of insects. Still making amends for the number of ant hills my brother and I cooked with the sun.
On a side note and in a similar direction. Would it be feasible to make a solar concentrator that heats a molten-salt reactor that powers a turbine engine? On a small-ish scale though, such that it'd be achievable as a back-yard reactor?
So the description I used above was my memory-driven understanding of it. But here is what I actually meant: https://en.wikipedia.org/wiki/Solar_power_tower
Edit. I went down a little rabbit-hole, HN. This is what I eventually found about small-scale energy generation using solar-concentration.
https://en.wikipedia.org/wiki/Solar-powered_Stirling_engine
https://en.wikipedia.org/wiki/File:Dish-stirling-at-odeillo....
Could be a semi-viable alternative to solar, perhaps? Though cost-wise, it's probably quite high now that solar-panels and their auxillary hardware have been commoditized so much.