Enerji ve Çevre Dünyası 26. Sayı (Mayıs-Haziran 2004) / Energy & Cogeneration World - Enerji & Kojenerasyon Dünyası

Market Potential The potential scale of CHP development depends on the size of the heat demand accessible for supply by CHP plants. it is often argued that the potential for CHP is limited due to scarcity of adequate heat demand. This claim is generally substantiated by focusing on l arge district heating systems, whose further expansion may be inhibited by penetration of natural gas supplies into housing areas. But gas may also fuel CHP installations. The introduction of internal combustion engines and small gas turbines as CHP generators made a large variety of heat demands accessible to gas-fired CHP. On this basis, various market studies carried out in the 1990s concluded that, in Europe, CHP plants could generale 40%-50% of the total electricity demand. in fact, this level has already been exceeded in Denmark and the Netherl ands. This market potential for CHP may even be increased by the development of micro-CHP technology. lnternal combustion engines supplying CHP at electrical capacities of only a few kilowatts are already on the market. Quite a number of manufacturers are engaged in the development of fuel cells or Stirling engines with electrical capacities down to one kilowatt. They aim at repl acing conventional gas heating systems for individual houses. Market surveys have suggested annual sales of many millions of micro-CHP generators. Such prospects may come true if a real technological breakthrough is achieved, making micro-CHP devices as simple, reliable and cheap as current conventional gas heating devices. The medium-term potential for CHP penetration may be enlarged by the development of micro-CHP. However, will the expansion of power production from renewable energy sources (RES) restrict the potential for CHP? Both CHP and RES production reduces consumption of fossil fuels and thus avoid emissions. in the energy supply sector, their development is by far the most important contribution to climate protection and conservation of resources. Furthermore, except for l arge hydro plants and offshore wind parks, RES power in general is decentralized production that also, like CHP, relieves the load on electrical transmission s R y E s S te m s . power based on biomass, geothermal and sol ar thermal energy should be produced in combination with production of useful heat -that is, in CHP plants. in this ARTICLE / MAKALE sector, expansion of RES will not restrict the potential for CHP. However, RES power generated by photovoltaic, wind and hydro power constitutes an area of power production obviously not accessible to CHP. Will the expansion ofpowerproductionfroın renewable energy sources restrict thepotentialfor CHP? The concentration of large hydro power capacity has already limited the use of CHP. in Norway, for example, where almost 100% of electricity is generated by hydro power, CHP does not exist. in principle, the further expansion of power generated by photovoltaic, wind and hydro power may limit the potential for CHP. But there is little potential for expansion of hydro power from rivers in Europe; exploitation of wave and tidal power is stili far away; and photovoltaic power will not contribute an important proportion of power generation in the short and medium term since considerable development emfefodrtiuims stetilrimre, qthueired to cut down its high cost. Thus, in the potential for CHP could only be restricted by the expansion of wind power capacity. Until now, this has been a real problem only in Denmark, where the share of both CHP and wind power in the total power generation is higher than anywhere else. in the long term, energysupply will have to be based predominantly on RES. But in the short and medium terms, the potential to replace conventional power will be higher for fossil-fuelled CHP than for RES. CHP capacity may be developed rather rapidly once adequate market conditions are established - as demonstrated by the examples of Finland and the Netherl ands. Eventually, the infrastructure now installed for fossil-fuelled CHP may, at least partly, be converted to CHP based on biomass, geothermal energy or, in southern areas, solar thermal plants. Conclusions The expansion of renewables-sourced power in the wind, photovoltaic and hydro power sectors may substantially diminish the potential for CHP in the long term, but not in the short and medium terms. The technical potential for CHP development is huge compared to the current market penetration in most countries. in Europe, the state of the current power plant fleet is now favourable for penetration of CHP. After a long period of over-capacity in most of Europe, existing plants are now degrading due to ageing. in some countries, the phasing out of nuclear power is also planned. Therefore, a large proportion of the European power plant capacity has to be replaced in the period 2010-20. Decisions to be made on the allocation of emissions for power plants in the European emissions trading system will exert an important influence on the choices for the next generation of power plants. it seems probable that CHP will benefit from emissions trading in most, but not ali, of Europe. The rising trend in electricity prices is also favourable for CHP but this effect is partly offset by high prices for natura! gas. The CHP Directive will create not much support, but some. Ali in ali, the prospects for future CHP development in Europe seem to be brighter than in the recent paEN s E ı R . Ji & KOJENERASYON DÜNYASI 63

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