Talk of the Town, March 25 2011

Are you tired of windmills that break, and unhappy about the ever-escalating price of Eskom electricity to extract water from boreholes? Then there’s good news. An entrepreneur from Alexandria, Hennie Hancox, believes he has a cheaper alternative.

While the use of solar power to pump water from borehole is nothing new, Hancox’s system is different in where the controller is located. It works on alternating current meaning any 3-phase pump motor can be used.

Hancox said a typical borehole of 130 metres depth and 2.2 kW pump (used during the 5.5 hours of sunshine per day) will deliver about 3 300 litres per hour or 18 000 litres per day. In this case 3.2 kW of solar panels will be required (32x100W panels)

Most solar pumps commercially available provide only about 1.1 kW.  This limits the depth that can be used effectively.  “With the controller I designed, there is no limit of the water withdrawn and the volume of water required.  It is simply the size of the pump and some solar panels that should be adjusted accordingly.” said Hancox.  He added that the further the borehole is located from a power point, the more expensive it is to extract the water with electric pumps.  For farmers, such an application would normally involve erecting windmills or wind turbines in order to pump the water.

Hancox’s system is far less to repair because a borehole pump and motor is normal 3 phase borehole system whereas the solar pump and motor system varies from R12 000 to R20 000 to replace.

Alex Pump’s Hennie hancox with the pump controller which works with any 3 phase motor.

The solar panels installed on a farm at Canon Rocks, provided enough power to pump water from a depth of 130 meters, and with a 2.2kW motor, at 3 300 litres per hour.