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

NyOrka Page 41 12/18/2008example of the trends but comments have been sought from developmental experts inorder to ground the realistic possibilities.This is the essence of the hydrogen handling chain; it is likely to be produced locallyfrom various sources, transported minimally unless it is generated as a by-product inindustry or produced centrally from gas or other carbon sources where the carbon dioxidecan be sequestrated as well. All extra handling poses extra costs because of the lowenergy density pr volume hydrogen. Large electrolytic centers will therefore beconnected to nuclear power stations and gasification, but smaller units, even local (home,office buildings, and community centers) power stations may be coupled to off gridrenewable energy conversion equipment.As of yet, the hydrogen technology is in rapid development and therefore investments inlarge systems has not occurred; investors are waiting for more mature components. Pricefor petrol and decreased cost of an entire new infrastructure must give added value to theinvestors and the public before major changes will occur. The bio-fuel chain still has astronger stand on the world market as a newcomer in the environmental technologysector.Usually electricity is the only source of energy used in electrolysis. But the process isexothermic. It has been shown that the electrical energy can at least partially be replacedby heat. 52 Research is ongoing on high heat electrolysis, but when electrolysis is carriedout in temperatures above 700°C 10 – 20% of the electricity can be saved. Currently thecost and efficiency of electrolysis is not competitive to using steam reforming fromcarbon containing fuel.A reversible fuel cell /electrolyser has been demonstrated as an experimental unit.6 Specification of future technology configurationsTable 17 Hydrogen production technology datasheet: Electrolysis 53ELECTROLYSIS (30 BAR OUT) 2020 UnitSpecific hydrogen capacity (out) 2.500 kW(H 2 )Specific investment cost 500 €/kWTotal investment 1.250.000 €Annual operating hours 8.000 h/aLifetime 20 aAnnual hydrogen production 20.000.000 kWh(H 2 )/aOperation and Maintenance 1,5 % of investmentAnnual Operation and maintenance 100.000 €/aAnnuity 127.315 €/aTotal annual cost 146.065 €/aEfficiency (electricity-hydrogen) 70 %Input electricity 1,4286kWh(El.)/kWh(H2)Output hydrogen 1 kWh52Mansilla1 Christine, Jon Sigurvinsson1, André Bontemps, Alain Maréchal, François Werkoff: Heat management forhydrogen production by high temperature steam electrolysis, CEA, 200553 HySociety, 2003, Basic table of carriers and barriers, edited and updated by FhG-ISI, 2005 and Icelandic NewEnergy 2006