Review Paper: Solar-assisted heat pump research and development

The main findings of a detailed literature search on solar-assisted heat pumps (SAHP) are presented. The various system types are described and the relevant performance criteria by which systems can be assessed are defined. Where possible different system performances are compared and specific conclusions drawn. While most work in the literature has focused on series systems there is no evidence that these can compete with parallel systems, either in non-purchased energy delivery or, more significantly, in cost. Efforts to improve control strategies for series systems are unable to achieve better performance. Technology is sufficiently advanced to exploit the best of these systems if the economic climate becomes favourable. Some suggestions are advanced as to where future research effort can make a useful contribution.