Mark Twain's hard lesson for solar energy investors

Conventional wisdom holds that the right time to invest in something is on "pullbacks," when the sector you want is beaten down.

Based on that conventional wisdom now is the time to invest in solar energy stocks.

A sudden glut of polysilicon, used to make solar panels, has hurt industry earnings. Despite fears of a shakeout and even lay-offs, growth remains solid and $2.3 billion in stimulus is coming.

Of course, as Mark Twain learned, just because a technology is ripe for investment doesn't mean you have the right horse. This is especially true in the area of solar energy. (To the right, Twain's investment, the Paige Compositor. From the Mark Twain House & Museum in Hartford, Conn.)

While some investors insist breakthroughs are not necessary, they are happening nonetheless.

Bio-Solar says it can make cells without plastic, Bill Gross' eSolar says it can cut production costs dramatically with software, and the University of Arizona is working on a film that can generate solar power from clothing and window shades.

Solar cell efficiency is another promising avenue of research. Or just add a middleman, algae, and produce fuel directly from it, as Joule Biotechnologies promises.

This is great for consumers, great for the future, but bad for businesses in the short-term, because they have to commit to producing something and convincing the market it's worth buying now. Some 46 Energy Frontier Research Centers have just been funded, to the tune of $377 million. Any one could turn the market upside down.

In terms of investment options, in other words, this remains a place for venture capitalists who can evaluate a ton of deals, place a lot of bets, and come up a winner if one in 10 comes up trumps.

Unless you are prepared to take losses, this is not the time for ordinary investors to take a plunge.

This post was originally published on Smartplanet.com