09-07-2013, 05:21 AM
The main takeaway I have from the ABC article is that Germany is heavily dependent on wind and solar for alternative energy as they are heavily subsidized there. The problem they are running into is that those sources are quite variable and the timing of power availability actually collides with other, more conventional, sources of power. For instance, the article cites a pumped storage hydroelectric plant that has become almost unused because it is designed to produce power during the day and pump water to a higher reservoir during the night when electricity supplies are unused and cheaper. Now with so much solar on line during the day competing as power sources there is little reason to release the water to power the hydro generators. Additionally, because of the unreliability of wind and solar, their "brown coal" (soft coal, a very polluting form) power plants have seen an increase in production!
This problem has been discussed by Pahoated and others as the clear benefit of the steady state nature of geothermal generation compared to the variability of wind or solar. The major traditional cost of electricity (other than hydroelectric) has always been the energy cost of heating fluids to produce steam to drive turbines. The energy sources are usually coal, oil or nuclear energy, all expensive to produce and with significant waste consequences (CO2 and radioactivity). Here in Puna we have essentially an endless source of free geothermal heat for the cost of constructing a power station. The article provides very strong support for geothermal in Puna and elsewhere as the primary source of electricity for Hawaii Island. It would even seem that, unless you are completely off grid, solar and wind electrical production would be largely irrelevant.
This problem has been discussed by Pahoated and others as the clear benefit of the steady state nature of geothermal generation compared to the variability of wind or solar. The major traditional cost of electricity (other than hydroelectric) has always been the energy cost of heating fluids to produce steam to drive turbines. The energy sources are usually coal, oil or nuclear energy, all expensive to produce and with significant waste consequences (CO2 and radioactivity). Here in Puna we have essentially an endless source of free geothermal heat for the cost of constructing a power station. The article provides very strong support for geothermal in Puna and elsewhere as the primary source of electricity for Hawaii Island. It would even seem that, unless you are completely off grid, solar and wind electrical production would be largely irrelevant.