Lu Aye, Fuller, R. J. and Charters, W. W. S., 2005 (in press) 'Ambient energy fraction of a heat pump', Solar 2005, Renewable Energy for a Sustainable Future - A challenge for a post carbon world, Proceedings of the 43rd Annual conference of Australian and New Zealand Solar Energy Society, 28-30 November 2005, Dunedin.

Abstract

Heat pumps are renewable energy systems which offer the possibility of reducing energy consumption significantly. This paper presents fundamental principles and applications of heat pumps in general. A new term "ambient energy fraction" for heat pump energy analyses is introduced for comparing an electric heat pump system with other systems for the same thermal output. The concept and the use of this term are discussed with numerical examples. The ambient energy fraction of an electric heat pump depends on the coefficient of performance (COP) of the heat pump and the power plant efficiency based on the primary energy used. It is highly dependent on the type of power plant used to generate the electricity to drive the heat pump compressor.

Keywords: Heat pumps; performance parameters; ambient energy fraction; primary energy ratio; COP