Objective Work has been carried out in order to incorporate a photovoltaic motor pump set within an existing solar water heating scheme. The match between a high performance direct current motor pump, the photovoltaic array and the solar water heating scheme has been investigated and the performance of the system has been monitored.2 different types of direct current motor were tested, a printed armature permanent magnet motor of lightweight construction and a standard direct current permanent magnet motor of heavy duty construction. There was a performance advantage to using the heavy duty motor which also suffered less in the humid conditions of the preheat tank room. The increased performance of the heavy duty motor was attributed to its greater inertia which made it more closely matched to the temperature inertia of the evacuated tube array.The principle of the photovoltaic powered pump to save power and provide independence from mains power supplies proved easy to implement. The best overall option for cost and performance was a combination of a standard motor and a cheap moulded plastic pump.A photovoltaic pumping system for advanced solar heating of domestic hot water has been monitored.The evacuated tube array revealed a greater than expected number of vacuum failures. Calculations, based on a comparison of manufacturer's data with temperature and flow data, reveal that the array performance is reduced by around 61%.Inspection of the printed armature motor showed brush wear consistent with nonarduous duty, although some armature wear had occurred and some corrosion of end plates and bearings was detected. Data was also collected for a heavy duty motor pump combination and a direct relationship can be shown between the motor speed and the array flow and the insolation level. Fields of science engineering and technologyenvironmental engineeringenergy and fuelsrenewable energysolar energyphotovoltaic Programme(s) FP1-ENNONUC 3C - Research and development programme (EEC) in the field of Non-Nuclear Energy, 1985-1988 Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator GEC Marconi Ltd EU contribution No data Address Elstree Way WD6 1RX Borehamwood United Kingdom See on map Total cost No data