OPINION: GETTING OFF THE GRID: Energy security crisis affects all South Africans

BY TERRY BILLSON - MARCH 17, 2015

Historically South Africans have enjoyed unquestionable energy security with Eskom being able to supply reliable electricity to industry and household at a relatively low price.

In recent years the cost of electricity has escalated significantly and the ability to supply has been severely compromised for a number reasons including lack of maintenance, political interference, increased demand on the grid and aging infrastructure. In addition to this South Africa has had to decommission some of its old technology generators (i.e. dirty coal-fired power station).

Whilst this pressure on Eskom’s ability to "keep the lights on” continues, the cost of renewables utilising solar photovoltaic has seen an evolution in technology as well as a reduction in cost. Getting off the grid is now a real possibility, while previously it was just too expensive to even be a consideration.

Effectively, getting off the grid means not being reliant on Eskom or any energy utility for electricity supply. It entails generating your own electricity when the sun is shining and storing it in batteries for consumption when the sun is not shining.

There are various degrees of reducing your dependence or reliance on the grid where going completely off the grid is the most expensive due to the requirement of electricity storage in batteries, and installing a net metering on-grid system can effectively reduce your electricity consumption, but this solution will not give you energy security because when the grid is down so will your photovoltaic system.

Another option, and what seems to be the most popular option, is installing generators.  From an environmental and operating cost perspective, this is certainly not ideal. The running cost of a fossil-fuel driven generators can be as high as R8, 00 per kWh, which is exceptionally high considering it is five times more than the average domestic electricity tariff. Generators also require constant maintenance and need to be started regularly.

If you wish to go off the grid you need to make sure that the building or house is as energy efficient as possible. Lighting, hot water, pumps, appliances, cooking etc. should all be converted first as this will ensure that you can specify a smaller photovoltaic generation system.

A typical home in Port Elizabeth will have a total installed capacity between 15 kW and 25 kW; this includes all major appliances such as kettles, geysers, refrigeration, lights etc. After energy efficiency initiatives this can be brought down to around 3-5 kilowatts, which will subsequently reduce the size of your photovoltaic system requirements.

Going off the grid should not be a simple exercise, there are a multitude of factors that can influence system design and the sizing of back-up required so make sure to use a reputable company for your photovoltaic requirements