SOLARWORLD Africa unpacks options for households and small businesses

Eskom has announced the start of loadshedding again and the reality of ongoing blackouts remains ever-present for South Africans. Households and businesses, in particular smaller businesses who do not have the luxury of large generators in an office or warehouse environment, continue to seek alternative power sources to keep the lights on.

According to Gregor Kuepper, Managing Director of SOLARWORLD Africa, there has been a marked uptake in renewable energy solutions as consumers start preparing for the worst – ongoing stage 6 loadshedding. “Solar used to be only a solution for large scale businesses or those with adequate space to house enough panels to support electricity consumption. Fortunately, and thanks to innovation in this space, homes and small businesses now have several options available to either provide temporary support when there is a power cut, and potentially, long term relief as the preferred ongoing power source.”

The SOLARWORLD Africa team have almost 40 years’ experience and a proven track record in Sub-Saharan Africa. Kuepper explains how the following solutions will keep the lights on - or the kettle boiling - and machines running during loadshedding ultimately becoming more self-sufficient or grid independent.

There are different types of energy systems: on-grid (grid-tied), off-grid, and on-grid with backup. “Grid-tied solar PV systems are most common in South Africa, as these are the most affordable and have the best business case. However, this does not necessarily ensure that you will be able to enjoy that cup of coffee during loadshedding. Grid-tied solar PV systems will generally be programmed to switch off during load shedding.”

Why is this? It comes down to international safety standards. However, it does not mean South Africans have to remain in the dark.

If you’ll pardon the pun, Kuepper ‘sheds some light’ on the different solutions:

Solution 1 – Grid-tied Photovoltaic (PV) system

A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. The two main components are PV panels (DC power) and a grid-tied PV inverter (DC to AC).

Why do you need a grid-tied PV inverter? It converts the varying DC power, from the PV panels, into AC power and feeds it to your household equipment and possibly into the grid.
What is meant by “grid-tied”? The inverter synchronizes the frequency and the output voltage to its connected grid. If solar energy is insufficient, a grid-tied PV inverter switches and starts drawing power from the grid into your home. It ensures there is a seamless power supply.

“This option saves electricity in the long run, no backup required. The pure PV inverters are grid-tied, this means they require the grid to switch on and convert the direct current (PV) into alternating current power which is required by appliances in your home.”

Solution 2 - On-Grid with Backup

2.1 PV and Battery

This is a backup and later self-consumption optimization (SCO) option. Self-consumption contributes to the distribution grid stability by avoiding voltage rise during peak PV generation periods such as the middle of the day, and helps to reach higher shares of installed PV in the electricity mix.

“When it comes to PV and battery, this can be served by either a hybrid (meaning PV and battery) inverter or separate battery and PV inverter. Your batteries act as backup power when the grid has failed e.g. loadshedding or a power outage. During a normal day, PV can provide power in a house and charge these batteries. This stored power can then be used during the night which is what we call SCO.”

2.2 Battery Backup

This is purely a backup solution and usually sized to make sure that your essential loads are up and running during loadshedding/power failure. Under the banner of pure battery backup, you also have various options. Such as a UPS, battery together with a charge controller and then of course battery and battery inverter. Of these, a battery with a good and reliable battery inverter is the most reliable solution.   

2.3 Battery and hybrid inverter

This is the same as the battery and battery inverter option except consumer have an opportunity to install PV panels at a later stage and do not have to add the extra cost of a PV inverter, as it would be PV-ready.

Solution 3 - Off-grid

In the current South African energy climate, this option sounds very enticing. It does however require careful planning and sizing of your system. You would require a large enough PV array to serve your daily loads and charge the batteries for use at night. And in turn, a large enough battery bank to serve the loads during the evenings and possibly during daytime, when there is not enough PV generation. There is of course the option to add a generator or to use the grid as backup.

Kuepper advises that a tailored approach will see various renewable energy solutions and products being recommended and made available. “Consult the experts, weigh up the options and also find a solution that not only meets your electricity consumption needs, but that is also financially viable - and always consider the long term benefits as certain products are designed to go the extra mile.”

For assistance finding the right solution, contact SOLARWORLD Africa via their website or call 021 421-8001. We have an extensive network of installer partners across South Africa and we would be happy to put you in contact with one of them.