On Mar 17 and 18, the first "International Summit for the Storage of Renewable Energy" took place in Duesseldorf, Germany. Their web site
http://www.energy-storage-online.de has a number of interesting YouTube interviews, unfortunately all in German. My email here also draws on the following three sources, again in German. http://www.energynet.de/2012/03/07/warum-die-energiewende-dringend-energiespeicher-benotigt/ http://www.youtube.com/watch?v=AMSI_n6cxbw http://www.lichtblick.de/uf/Studie_2050_Die_Zukunft_der_Energie.pdf and the following report in English: http://www.umweltrat.de/SharedDocs/Downloads/EN/02_Special_Reports/2011_10_Special_Report_Pathways_renewables.pdf Germany's goal is to have 50% of all electricity from renewable sources by 2020, and 100% by 2050 or earlier. In order to achieve this along with the necessary infrastructural transformation, renewable energy (mainly wind and solar) is given absolute priority in the merit order. Whenever the renewable energy sources are able to generate electricity, they are turned on and their electricity is fed into the grid. The existing merit order rules do not privilege them specifically but they go by marginal cost and renewables have the lowest marginal cost. If there is excess energy in the grid, then the power stations using coal and gas must be turned off, not the windmills. In this way, the existing fossil power stations serve as backup for the renewable energy. Of course the owners of these power stations do not like this, and they recently scored a victory by gutting the successful German Feed-In Tariff program, see http://cleantechnica.com/2012/03/01/german-utilities-fight-solars-cost-cutting-merit-order-effect/ You might say it makes no sense to gut the feed-in program exactly at the time when nuclear power has been phased out. But this is exactly the point. Fossil fuel companies want to take the place of the nuclear power stations, and therefore they have to hinder renewable energy. Since fossil fuel generators are forced to adjust, storage is not important right now -- instead storing energy it is cheaper to adjust the ouput of fossil fuel power plants. But storage will play an increasingly important role starting around 2020 or 2025. What kind of storage are the Europeans thinking of? (1) pumped storage. Few possible locations are left in Germany, but Norway could become the pumped storage provider for the whole continent. Efficiency is 80% or higher, but capacity is limited. (2) Electrolytic conversion of electricity to Hydrogen and then use the hydrogen for vehicles. This is the product line of the British firm ITM power. I am speculating this might be useful for a farm in the US off the grid with windmills, so that they can replace some of their diesel trucks by a hydrogen-powered truck? See http://www.itm-power.com/ (3) The Austrian firm SolarFuel GmbH turns the hydrogen into methane (preferably using CO2 from the air!) for feeding it into the natural gas pipelines or for natural gas vehicles. The efficiency of the natural gas process is much lower than pumped storage, they don't even say how low it is, other than saying it is below 50%, and its theoretical maximum attainable efficiency seems to be 60%, but the big advantage is that it has unlimited capacity and the natural gas pipeline network already exists. Therefore this system can be built up gradually starting right now, and productivity improvements will happen as more and more systems are produced. http://www.solar-fuel.net/en/solarfuel-gmbh/ (4) Thermal storage associated with Concentrating Solar power plants. (5) Thermal storage associated with micro-CHP swarm generators. The firm Lichtblick wants to install 100,000 micro CHP units produced by Volkswagen in large one-family homes or similar. They are owned and controlled by Lichtblick and they produce electricity for the residual demand when the sun does not shine or the wind does not blow. The waste heat is stored and the home owner can heat his home from this stored heat. The home owner pays Lichtblick for the heat withdrawn from this storage, while maintenance of the unit and the natural gas bill for the unit is paid by Lichtblick, from the receipts Lichtblick receives from the electricity generated by the unit. The following web site is unfortunately only in German, if you understand German you should watch the video about ZuhauseKraftwerk. http://www.lichtblick.de/ Hans thinks this is good for old buildings of historical value which cannot easily be insulated, etc., but new homes will not have enough heating needs for this to be feasible. It would also not work for air conditioning, it only works in a northern climate. This shows how much these ideas depend on the local conditions. (6) Battery storage if there will be a cost breakthrough in batteries, or in a vehicle-to-grid scheme. Hans. _______________________________________________ pen-l mailing list [email protected] https://lists.csuchico.edu/mailman/listinfo/pen-l
