Can "green tech" have a dark cloud?

This New York Time Magazine article on green venture capital makes me simultaneously hopeful and nervous.

Kleiner Perkins is one of the giants of venture capital, having scored with some far-sighted early bets on high-tech firms such as Google.  Now, the firm is setting its sights on "green tech" -- technologies that can save energy, produce renewable power, or reduce pollution and emissions. 

Having such deep pockets turning their attention to clean energy seems like a very good thing.  And to my eyes, Kleiner seems to have gotten one important point right:  much of the technology we need to transform the energy system is already out there.   Says Kleiner elder statesman Bill Joy:

"Our overarching thesis...was that a lot of stuff had already been developed, but there were things that were not yet commercialized because thy had been frozen by the low price of oil.  The innovation had occurred, but they hadn't been deployed."

This is a point that greenies have been making for decades:  cleaner tech is already on the shelf, but structural impediments (including the subsidies we lavish on fossil fuels) have prevented them from taking off.  And it's wonderful to see that idea going mainstream.

Still, I do get a bit nervous about some of the energy technologies that the article touts as "green."

Take, for instance, the "Bloom Box," a squat, refrigerator-sized fuel cell that can turn natural gas or other fuels into electricity with remarkable efficiency.  Kleiner has made a big bet on Bloom, but there's a flipside:

The company's ambitions are indeed breathtaking in scope...."Two billion people have no access to electricity.  And of the four billion people with access, probably two billion are actually getting below their demands."  That makes a lot of potential users of his product.

Obviously, the Bloom Box could do good things for global economic equity, by giving more people access to reliable electricity. But more than anything else, the Bloom Box is a technology that makes fossil fuels more useful.  Spreading natural gas-powered Bloom Boxes across the less-developed world will likely make global climate and energy problems worse, not better -- it will make even more of the world's population dependent on an unstable resource with frightening impacts on the climate.

I'm not arguing that the Bloom box is a bad idea:  I'm sure it's got some great potential.  Still, I think it's worth being cautious about what technologies people tout as "green." Sometimes, even a super-efficient technology might not do much good for the planet.

This piece originally appeared on The Sightline Institute's blog, The Daily Score.