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How large a PV system do I need?

Q:

How large a PV system do I need?

A:

There are a number of factors that influence the size of a PV system required for powering a pump.

The first is the size of the pump itself. The larger the pump, the more solar panel area it takes to operate it well. The Lorentz CS17-1 requires a minimum of 700 watts of South facing panel. The larger Lorentz CS37-1 requires at least 1600 watts to work well.

Ideally somewhat larger PV arrays would be used for better early and late day performance.

In terms of physical size, right now with good solar PV panels being about 16% to 18% efficient, a 750 watt array will be about 4.9 square metres (50 sq.ft.) in area and an 1800 watt array will be about 11.8 square metres (126 sq. ft.).

If the PV panels are facing more than 30 degrees of of due South, or are partially shaded between 8am and 6pm, The array must be made larger to compensate for reduced performance during part of the day. How much larger the PV array must be, can only be determined by an on-site visit.