Combined heat and power systems: always suitable? The Portuguese case

Abstract

The energy markets are currently under tremendous pressure caused by instability in fuel prices and environmental issues. Thecitizens are affected by the constant increase in fuel prices, threat to the security of energy supply and by climate change resultingfrom an environmental policy neglectedSo, cogeneration systems arise as a way of producing high efficiency energy, lower environmental impacts, and a decrease in theconsumption of primary energy. However, cogeneration, to date recognized as one of the most efficient ways of producingelectricity and thermal energy, has seen its future in jeopardy because of the recent austerity policies which have decreased theremuneration regarding the electricity produced.The objective of this work is the approach to the new legal framework applicable to the cogeneration activity in Portugal. In thatway, an energy audit was done based on an existing cogeneration plant. A comparison of the results obtained by applying the newlegal framework with the results obtained by previous legislation was carried out. The avoided CO2 emissions were comparedwith separate heat and electricity production. A sensitive economic analysis was carried out in function of the prices of electricity,fuel and cost investment.