A couple of years ago, Dr William Moomaw of Tufts mentioned a regional scale experiment with an all-renewable grid in Germany.  I’ve been curious about that project since then.  Today, I did a little googling and found a seven-minute youtube called “Fully renewable: biogas + wind + solar”

Dr Jurgen Schmid at the University of Kassel, Department of Efficient Energy Conversion is the spokesperson from this December 2007 video.  The system described is wind with pumped hydro storage and grid scale solar with methane from biomass (corn biofuels).  When the sun isn’t out in the South, the wind may be blowing in the North.  When there’s too much wind, it can be used to pump water into reservoirs that will provide hydroelectricity days or weeks later.  When the sun isn’t shining and the wind isn’t blowing, biomass can be burned or converted to methane.  They say Germany can have a 100% renewable grid by 2050.  Dr Schmid, along with John Sievers, Stefan Faulstich, Mathias Puchta, Ingo Stadler, is the co-author of “Long-term perspectives for balancing fluctuating renewable energy sources” (pdf alert:  http://desire.iwes.fraunhofer…. details the steps necessary to get to a fully renewable grid.