Electricity and Control September 2025

Renewable energy + industrial sustainability

Moving away from grid dependence Solar and battery systems have become so inexpensive that many private individuals, farmers and companies are recognising that in many locations in South Africa it is now less costly to be o the electrical grid than to be on it. Frank Spencer, spokesperson for SAPVIA, outlines the cost benefits of switching to solar, and highlights some concerns.

T he move away from the grid has been driven by two key factors. First is the rapidly rising cost of electricity supplied by Eskom and municipalities in South Africa, where tariffs have increased above inflation every year for the past 17 years. Second has been the rapidly declining cost of photovoltaic (PV) solar panels and lithium batteries over the same period, with manufacturing quantities growing exponentially each year and consistently

batteries + generator + fuel could still be less than the cost to buy electricity from the grid. The other is to switch to an electric vehicle, which can act as the backup to the solar battery system, and be recharged on the grid if necessary. The sunnier the location, and the higher the electricity tari•, the better the economics of grid defection can be, which is why this growing trend is more predominant in the northern part of South Africa. The big questions This raises the important question of: ‘Where does this leave Eskom?’, which, arguably, is too big to fail, and on which many who cannot a•ord solar battery systems are completely dependent. Those who leave Eskom raise the costs of electricity for others. Hence, another corollary question could be: ‘Is leaving the grid the right thing to do?’. At the South African Photovoltaic Industry Association (SAPVIA), we believe that the primary source of Africa’s and South Africa’s energy will be the sun (which also drives the wind and water systems that provide energy), including low cost solar and battery systems. However, it is also clear that the optimal delivery of low-cost power across South Africa should be done by a combination of solar, wind and battery systems, of all scales, and linked together by a modern transmission grid network. Such a distributed smart-grid can deliver reliable, a•ordable, clean electricity across the country. Private o•-grid systems are, in some senses, ine•icient,

Frank Spencer, SAPVIA.

exceeding even the most optimistic projections. Until recently installing solar and battery systems was done generally to save money during the daytime (due to the super cheap solar electricity production), and to protect against load shedding (through the battery component). However, for many locations in South Africa, it is now possible to generate electricity from such systems to cover the user’s daytime as well as nighttime demand, to the extent that remaining on the grid is no longer necessary. This is further being driven by the fact that the fixed costs to bring the wires to properties are now rising significantly faster than the energy charges to bring you electricity over those same wires. So why have the wires at all? It is true that to cover 100% of your electricity supply with solar and battery storage can be challenging. There are two cost-e•ective ways to mitigate the challenges. One is to install a backup petrol/diesel generator, where its occasional use may be expensive, but the combined cost of the solar +

In many parts of South Africa, it is now possible to generate su icient electricity from solar and battery energy storage systems to cover a user’s needs, so remaining on the grid is no longer necessary.

12 Electricity + Control SEPTEMBER 2025