Sustainable small-scale CHP technologies for buildings: the basis for multi-perspective decision-making

Generally speaking, the concept "small-scale CHP" (combined heat and power) means combined heat and power generation systems with electrical power less than 200 kW. The significant benefit of CHP is its overall efficiency, which can be as much as 85-90%. One of the most promising targets in the application of CHP lies in energy production for buildings. The most important competing technologies in this regard are reciprocating engines, micro-turbines, Stirling engines, and fuel cells. The benefit of these technologies is their ability to utilize sustainable fuels, like regenerative biomass, which makes them attractive. In spite of many technical and economic obstacles limiting the availability and feasibility of these technologies at the moment, the literature is optimistic about their future. The breakthrough of new technology is often regarded simply as a matter of decision-making. This article is a general review of issues that can be supposed to influence decisions when considering small-scale CHP as an alternative energy source for buildings. Firstly, a brief review is presented concerning the political, economic, social, and technological environment of small-scale energy production. Obstacles limiting the market potential of the new technologies are then listed, and solutions are suggested to improve their potential in Europe's liberalizing energy market. The relevant interest groups influencing decisions both for and against the introduction of the new technologies, as well as their status are recognized. Finally, the advantages and disadvantages of relevant small-scale CHP technologies are briefly discussed, with respect to building energy generation. Finland's role in this study is emphasized, but the international perspective is also dealt with.