Naslov
Technical status of Micro-Cogeneration Units with Hydrogen Fuel Cells

Autori
Firak, Mihajlo

Izvornik
Strojarstvo : časopis za teoriju i praksu u strojarstvu (0562-1887) 49 (2007), 3; 193-205

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Fuel cell; Micro-cogeneration; Hydrogen; Solar energy; Solar photovoltaic/thermal

Sažetak
Development trend of the energy sector nowadays are more and more under the strong influence of three kinds of problems: security of energy supply, unpredictability of energy market and influence of production and consumption of energy on the environment. In such conditions decentralized production of usable form of energy using primary renewable and unrenewable energy sources appears as one of the most important direction in the future. Regarding that in developed contries around 40 % of energy is used in households, 30% in transport and 30% in production, micro-cogeneration unit for households become more important. Micro-cogeneration unit is in fact made up of an assembly for production of usable form of heat (for example warm water or warm air) and an assembly for production of electric energy. Here, electric energy can be produced in different ways, for example by using a microturbine generator, Stirling´s engine generators, fuel cell systems etc. In this work there are two directions of the development of micro-cogeneration units shown, which comply with the definition of micro-CHP unit according to European cogeneration directive 2004/8/ES (electric power < 50 kW). The difference between described directions are made regarding primary energy, ie. CO2 emission: the first direction uses natural gas and during the work emits CO2, and the second direction uses solar energy and does not emit CO2 during the work. Within the first direction, only systems with fuel cells as generators of electric energy are considered. Concerning the type of fuel cell used, only PEMFC (polymer electrolyte fuel cell) and SOFC (solid oxide fuel cell) systems are considered. Within the second direction solar photovoltaic systems with cogeneration of heat are considered (solar photovoltaic/thermal or PV/T) which have the ability of using electrolyser/hydrogen storage/fuel cell subsystem as energy storage. A new concept of micro-cogeneration unit is also shown, the one which, besides the heat and electric energy for household usage, covers energy for driving the personel car, i.e. personal transport, so it should be called "micro-combined heat and power and transport unit". A review of efficiency of units of some leading producers according to mentioned directions is given. It is concluded that in transition period, when the prices of hydrocarbon fuels are still relatively low, efficiency of solar cells small, and lack of respect on restriction of CO2 emission is not sanctioned enough, development of micro-cogeneration units, based on fuel cells with natural gas as a fuel, dominates.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

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