Salt melts?

This was news to me -- news that defense contracting conglomerate United Technologies (NYSE: UTX) intends to use to ride the same wave of solar fever that has lifted firms like First Solar (Nasdaq: FSLR) and Suntech (NYSE: STP), Trina (NYSE: TSL) and SunPower (Nasdaq: SPWR) to prominence ... and profits. According to a press release, United Tech has stumbled upon a new way to profit from "free" energy: It's not going to compete with the solar panel makers, but complement them.

As you probably know, the second-biggest knock against solar (second to the fact that it costs more than most alternatives) is that when the sun goes out, so too does the power source. United Tech's solution: Store the energy. The firm's Hamilton Sundstrand subsidiary aims to partner with private equity shop "US Renewables Group" to establish a new company called "SolarReserve."

The aim of the new company: Commercializing a new form of solar power generation that can fill the gaps between sunrise and sunset left by the solar panel makers.

Power how?
With sun ... and salt. SolarReserve aims to construct concentrated solar power towers filled with a mixture of sodium and potassium nitrate salts. Details on this project, which is at least three years from viability, are scarce. But apparently, the towers will somehow gather and concentrate enough sunlight to sufficiently melt the salts and then store them and their retained energy until it is needed. Once that need materializes, the molten salt will be used to heat water to operate a steam turbine, which will in turn generate electric power.

How much power?
According to United Tech's press release, one tower can produce as much as 500 megawatts of power per year -- enough to meet the electricity needs of a small city of 250,000 households (about the size of Baltimore).

Pastry power
I know what you're thinking. And yes, promises of "free and inexhaustible" energy sources with "zero ... environmental impact" -- if you'll just wait three or four years -- sound a little pie in the sky-ish to me, too. But if anyone has the expertise to make something like this work, it's United Tech. The firm's products power jets for Boeing (NYSE: BA) and Embraer (NYSE: ERJ), and even the International Space Station.

These guys know how to bake stratospheric pastries.

As Foolanthropy enters its second decade, join us in working to bring financial education to the world's youth. Learn more about Foolanthropy's new direction.

Fool contributor Rich Smith does not own shares of any company named above. Suntech is a Motley Fool Rule Breakers selection and Embraer is a Stock Advisor pick. The Motley Fool has a disclosure policy.