A question many businesses are asking in 2020, particularly with the onslaught of load shedding, is the possibility of going entirely off grid. This is unsurprising – grid reliability has been severely reduced over the past few years and Eskom tariffs are substantially higher than the costs of solar on an average lifetime basis. As such, many companies are looking at the possibility of severing ties with the grid and managing their energy needs independently.
Historically, solar has not been viable as an alternative primary electricity supply to the grid primarily because of its variability. Because the sun only shines during the day, the deployment of solar has often been limited to partial offset of daytime electricity demand – a solution which tends to save companies significantly on their electricity bill. But for solar to be a ‘dispatchable’, 24-hour alternative to the grid, it needs to be coupled with storage, or with other flexible sources of demand or generation, which has often made it an expensive choice.
This, however, is changing. In South Africa, overall costs of solar-plus-storage have historically compared unfavourably to most grid tariffs, limiting off-grid projects to areas with no grid access or grid capacity constraints. However, there are already several industrial and commercial grid tariff structures that make off-grid solutions a cheaper and more reliable alternative than remaining on grid, particularly for industrial operations that have high power requirements and tend to supplement their supply frequently with diesel generators to keep their electricity supply consistent.
How do you know if it is viable for your company to go off grid? One of the key questions to ask is how much your business currently relies on diesel generators. If you use them around 15 – 20% of the time, it is almost certain that a solar + storage solution will save your business money. Secondly, if your facility has large power (kVA) requirements and is on a high industrial tariff, the business case of going off grid could be advantageous.
Cost reductions and improved efficiency in energy storage technology have major implications for the future of South Africa’s power system: it means that some electricity consumers on expensive tariff structures can already choose an alternative to Eskom or their local municipality. Even those on cheaper tariffs are likely to follow as grid tariffs rise and solar and battery equipment gets cheaper.
Of course, large-scale grid defection might not be the ideal outcome for all South Africans. It will erode the economies of the national grid and increase costs for many segments of society. This is why power sector reform must urgently facilitate an efficient and equitable transition to renewable energy.