Impact of combined heat and power plant on thermal and electrical energy supply for small and medium size enterprises

Combined Heat and Power (CHP) plants serving Small and Medium Size Enterprises (SMEs), form the back bone of on-site generation capacity, replacing existing on-site thermal energy plant and substituting, to a large extent, the commercial electricity supply. Other benefits of CHP projects include: reduction of greenhouse gas emission, increase in SME business reliability, improved electrical power quality, increased energy efficiency, resulting in significant financial and environmental benefits. The generation and supply of electricity from power stations is generally at an efficiency in the range 25%-50% based on the Gross Calorific Value (GCV) of the fuel and including transmission and distribution losses. When employing recovery of waste exhaust heat, CHP schemes typically achieve overall efficiency of 60%-80% and sometimes more, as well as achieving a reduction in harmful gas emissions. The case study for the paper was undertaken at a large hotel. The paper discusses findings and results based on one year´s data collection (2006) in order to give an insight on CHP impact on electrical and thermal energy supply as well as on the emission of greenhouse gases, particularly CO₂. Also the paper gives an insight on the operational performance of the CHP plant such as: effective electrical efficiency, effective thermal efficiency, total CHP efficiency, percentage fuel savings and CO₂ emission savings.