Jun 7, 2009

Methane Could Be Storage Solution for Solar and Wind Power

In a surprising find, scientists have discovered a microbe that can efficiently convert direct electrical current into methane.

That may be good news for wind and solar power enthusiasts, who have long been faced with the dilemma of how to store energy when the wind isn't blowing and the sun isn't shining. This discovery opens the door for generating methane from those renewable power sources; the energy could then be stored as fuel for later use.

But is storing renewable energy in the form of a greenhouse gas like methane a solution, or just another problem?

The remarkable microbe, Methanobacterium palustre, is the first to be found which can biochemically synthesize methane using electrons directly from current in combination with hydrogen gas. Most significantly, it appears to transform the energy at 80% efficiency. That's pretty darn good, according to researchers.

Before this discovery, the options were limited regarding how to store energy generated from wind or solar sources. Storing it in large capacitors and batteries offered the most practical solution, since converting the energy into a fuel like hydrogen made it difficult to compress and store. But that problem doesn't exist for methane, which is the main component for natural gas. Natural gas is already carried around the world in pipelines, and it's used in conventional engines.

Though despite the good news, utilizing this process may overlook some of the bigger reasons for switching to renewable energy. Specifically, if the primary benefit for using wind and solar energy is to reduce greenhouse gas emissions, then wouldn't converting that energy into methane miss the point?

Yes and no. Methane is a very clean burning fuel, and compared to other hydrocarbons, burning methane produces less carbon dioxide for each unit of heat released. In other words, if the choice is between storing excess wind or solar energy as methane or having to use traditional, dirtier fuels like gas or coal to pick up the leftover energy burden, then converting clean energy into methane- while perhaps not the ideal solution- is still a significant step forward.

More research needs to be conducted to determine the exact molecular mechanism of the biochemical process, and practical means for employing the technology have yet to be worked out. But the exciting discovery does shed some creative light on the potential for renewable sources to supply all of our energy needs.

Reprinted with permission from Cleantechnica

By Bryan Nelson

6-4-09

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