ABSTRACT
In 1999, Staatsbosbeheer, the Dutch National Forest Service, commissioned a redesign of the nature reserve "De Steendert" which had to content with severe drought. A 5ha storage pond was made for irrigating the area. Accepted fluctuations in the pond allow for several day's water buffer. Ecofys supervised the construction by VOPO of a dual photovoltaic pumping system, which controls the water level in the pond. The system consists of two 45m3/h pumps, one powered by an 1kWp photovoltaic array with 230 Ah battery bank and one direct powered by an 1 kWp photovoltaic array. Measurement equipment is installed in order to measure and compare both systems characteristics. The aim of this research is to compare the technical and economical feasibility of both pumping systems. Expected achievements are: reduction of BOS and maintenance costs and ecological friendly system design by elimination of the battery bank. The energy generated by the photovoltaic modules covers the demand of the pumping system during a reference year. Direct-coupled pumping systems are expected to be both economically and technically competitive with their battery-backed counter parts.
