Solar Water Heating in South Africa
To practically demonstrate our commitment to renewable energy we chose to install a solar water heating system on the house in South Africa.
With the current low cost of electricity (R0.504/kWhr (about 4p/kWhr)) this is unlikely to achieve a payback. However, it was installed with the construction of the house and so the installation cost was 'lost' in the overall build.
This active open loop solar water heating system is made up of the collector, the storage tank or geyser, and the electric pump.
The collection system is three flatplate collectors each being an insulated in weather-proofed box containing a dark absorber plate under a translucent cover.
The geyser is a standard South African geyser with immersion heater as a standby. There are ample connections for the additional solar heating loop and it is well insulated.
The system now uses a 12 volt brass pump to recirculate warm water from storage tank through the collectors and piping. The pump is powered by a small solar panel and so operates when their is solar energy available. It was originally fitted with a mains electricity cast iron centrifugal pump controlled via a differential temperature controller. After 12 months operation the domestic hot water was showing signs of discolouration so we decided to replace the pumping system with the simpler (but more expensive) solar pump.
Benefits of Solar Water Heaters
We have ample hot water at all times and the system controls itself. It operates 24hrs per day 365 days per year without interference. Since the installation of the solar pump it has been maintenance free.
For more information contact Mearsecroft
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