How electricity generation has changed over the past 10 years – and what it bodes for our future

Alongside the global pandemic, electricity has been on many South African’s minds this year. And rightly so: South Africans can expect a 15% increase in their electricity costs from mid-2021, based on a recent court ruling which grants Eskom the right to recover operating costs through additional tariff escalations. This will mark more than a decade of average annual increases of 14%, relative to average inflation of just under 6%.

These escalations have fundamentally changed South Africa’s economy: the manufacturing and mining sectors have been particularly affected by the rising tariffs, and are doubly affected by the inconsistent supply caused by load shedding. South Africa’s electricity supply from the grid is subject to decreasing reliability, with 2020 already shaping up to be the worst on record for load shedding.

What South Africa is experiencing is not unique, but exposes the global trends that expose the high costs of maintaining an aging and centralised coal fleet. A decade ago, average Eskom tariffs were two times lower than they are today, and the costs of installing solar PV were two to three times higher. That situation is very different today: Eskom and municipal electricity tariffs are now substantially more expensive than solar PV installations on an average, lifetime cost basis. This is driving strong uptake of own-use solar generators, despite persistent policy and regulatory barriers.

This is because the electricity market has fundamentally changed over the last 10 years. The growing cost gap between the grid and solar PV means that the benefits of solar are more economically viable, even if the PV plants generate more power than required (for example on weekends, when a factory does not operate). 

For private electricity consumers, solar electricity is typically used to offset daytime electricity consumption through ‘own-use’ or ‘embedded’ generators that service the electricity needs of the facility on-site. The uptake of embedded solar generation has exploded in South Africa, particularly amongst the retail and manufacturing sectors, because of the cost savings generated by the plants. Despite this, embedded generators are largely restricted from selling power into the grid, although it is looking hopeful that this might change. 

The fact that solar PV is so much more affordable than Eskom’s grid is also changing the way in which solar PV is consumed by large commercial and industrial facilities. For example, some facilities choose to oversize their solar PV system relative to on-site electricity demand in order to increase morning and afternoon solar electricity production, generate more power in winter, save more diesel during load shedding, reduce peak grid demand charges, and achieve higher overall reductions in grid electricity consumption. 

Other commercial and industrial facilities are opting to oversize their solar PV systems and store the excess affordable power in battery banks – something that, 10 years ago, would have been ludicrously expensive. However, with Eskom’s tariffs increasing the way they are, and with the reduction in the costs of energy storage components, the business case is starting to emerge. The advancement in electricity generation technology gives businesses more flexibility and options when it comes to their energy choices. Own-use solar – whether on or off grid – is an affordable and, by now, well-used option.