Generation, of the energy carrier HYDROGEN In context ... - needs

NyOrka Page 19 12/18/20084 Electrolysis technology development pathwaysThe drivers for using hydrogen as energy carrier or buffer for grids are:• Distributed production i.e. near the customer• Diversification of energy sources and availability of water supply• Clean operation, - important in cities to lower sooth• Good integration possibilities with established electric systems and modules• Buffering opportunities to meet fluctuations between production and demand withrenewable energy systems• Stand alone applications in remote areas possible• Benign environmental effects during use phase• High energy quality characteristics• Combined heat and power production with use of certain Fuel Cells• Easy integration with upcoming transport schemesDuring the first stages of introduction, hydrogen from industry and central gas reformingis seen as the main source. Hydrogen will be foremost used as fuel for transport withelectric vehicles, and in figure 8 Hydrogen is placed as fuel at the future end fordecarbonised fuel types, but hydrogen technology has been used in viable energy systemsfor decades Two main pathways are predicted for electrolysis when demand rises in thesecond and third decade of the 21 st century; Electrolysis using PEM electrolysers on onehand and high heat, high pressure lye electrolysis on the other. The PEM technology isforeseen as a small module for specific applications while bulk production may requirelye electrolysis, which is proven technology. High heat and pressure electrolysis shouldoccur at temperatures near500°C (supercritical heat) ormore and is foreseen in contextwith solar thermal towertechnologies, high geothermalheat and nuclear power coolingfacilities.Figure 8 Energy road-maps for thenew century predict that fuel typesfor transport, will containgradually less carbon. 14 .Due to purity demands, theselected hydrogen deploymenttechnology will influencewhich production pathway isused. The PEM fuel celldemands high purity while other types of fuel cells can use hydrogen mixed with othergaseous fuel. The PEM is promoted in context with transport drive trains as they arecompact and operate at temperatures below 100°C. Recent developments have shown14 Minns David (editor) 2005, APEC 2030 Integrated Fuel technology roadmap