Taxpayers may have been forced to invest in solar panels, but private investors with a choice aren’t quite so foolish. From today’s Motley Fool column titled “Here are some American eco-investments to avoid” including thin-filmed solar:

I’m dogging (oo-er! — Ed) one of my own investments here, First Solar (NASDAQ: FSLR.US), but outside of that one success story, it’s hard to find anyone who has made any real progress in thin-film solar. Ascent Solar and Energy Conversion Devices at least made it to the public markets before running into problems, and likely an eventual bankruptcy. Solyndra, which was based on thin-film technology, was a colossal failure, and the CIGS technology it used has failed to live up to industry expectations.

But the biggest reason thin-film solar is a money pit is that there are too many higher-efficiency modules on the market at attractive prices making thin-film uncompetitive. Thin-film solar is lower efficiency requiring more land, and other installation costs versus competitors. For a look at how important these balance of system costs are becoming, check out my article about these costs here.

Ouch! Right now Ascent Solar‘s stock is sitting at .63 cents, and Energy Conversion Devices’ stock price is up to .36 cents. ECD is where you’ll find former Abound Solar VP Julian Hawkins. Abound, which also makes thin-filmed solar modules, isn’t listed because its not a publicly traded company. Based on what Motley Fool said above, Abound likely would be a foolish investment too.