Farmers are making increasing use of photovoltaic solar panels and variable speed drives (VSDs) to get clean and continuous power to their boreholes in remote locations, cutting out the need for costly infrastructure and cables to link with the main grid.

Zest WEG Group, a subsidiary of leading Brazilian motors and controls manufacturer WEG, supplies these stand-alone electrical solutions so that users in the agricultural sector can immediately benefit from ‘free’ solar power for pumping water.

As a key element of this arrangement, the VSD protects the motor from the fluctuating energy flow of the solar panel, allowing the motor speed to vary as the strength of the sun’s rays changes with weather and times of day. This ensures maximum system operation during the day while protecting the motor and VSD. In addition to this, the VSD also offers a variety of other motor protection features such as over voltage, under voltage, phase imbalance, phase loss and over current which would normally have had to be done by other external equipment.

The appropriate model of VSD is selected from the range of WEG units, to suit the size of motor and pumping capacity required. Typically, the photovoltaic option is chosen for motor sizes up to approximately 5,5 kW, but larger motors can also be catered for by installing more solar power capacity.

The added value in WEG’s VSD includes the company’s in-house software that allows its highly skilled technicians to optimise the performance of the motor and pump, according to the application.

The solar powered option also eliminates the potential voltage drop over extended lengths of electrical copper cable between the source and the motor, as well as the possible theft of this cable and the resulting disruption and added cost.

Supporting customers is key to Zest WEG Group’s operating philosophy, and the Group operates a network of strategically situated branches and distributors across South Africa and the continent.

Experienced technical staff is available countrywide to advise customers, as well as to set up and commission this innovative, renewables-based solution.