Scientists at MIT have figured out a way to harness the sun’s energy much more efficiently than the photovoltaic panels that you may be more familiar with. The researchers have focused on using the sun’s heat to boil water, and to use the resulting steam to drive turbines. This approach, called solar thermal, isn’t a new one, but the group at MIT may have found a way to make it much more efficient. As the Economist reports, the team drew inspiration for their new method from wet roads:
[A] group of researchers at the Massachusetts Institute of Technology (MIT) has come up with an…approach that borrows from the wet road. Steam is generated at the surface of water, but the mass of liquid below acts as a heat-sink that conspires against steam generation. This is why sunshine can readily turn a thin layer of water on a road into steam but cannot do the same for a lake.The MIT researchers sought to address this in a laboratory set-up that consists of a double-layered black disc floating on the surface of water in an insulated beaker…This simple disc turns out to be a very efficient steam generator. For one thing, it produces steam when sunlight is magnified by a factor of just ten. This requires little more than cheap lenses and it increases the efficiency of using solar energy to make steam to 85%. With some refinement of the graphite layer, thinks Dr Chen, the technique could be made to work with sunlight that is concentrated as little as three times.
This is an excellent example of the kinds of research governments and green groups interested in sustainably powering the future ought to be funding. Instead, countries like Germany have thrown massive amounts of money behind current-generation photovoltaic panels, a solar technology that is incapable of competing with fossil fuels on its own merit. Not only is this kind of short-sighted subsidization a drain on government coffers, it carries with it a hefty opportunity cost. Who knows where we’d be if policymakers had taken all of the money with which they’ve been propping up today’s solar technologies and invested it in the research and development of cost-effective and more efficient methods of capturing the sun’s energy.More of this, please.