Solving South Africa’s energy crisis: the case for a hybrid energy system
By Ajay Lalla, Lesedi Nuclear Services Project Development Specialist
South Africa’s energy crisis has reached a critical juncture, characterised by frequent power outages, escalating electricity tariffs, and an over-reliance on coal-fired power plants. These challenges have left the nation in urgent need of a sustainable energy solution. We’ve seen many consumers installing PV solar solutions with battery storage systems to negate power outages with the aim of ultimately becoming independent of Eskom. Our energy challenges have also catalysed the green economy to meet net-zero carbon emissions by 2050.
While renewable energy sources, notably photovoltaic (PV) solar and wind turbines, have attracted substantial investments as potential remedies for the crisis, their inherent intermittency and inability to provide dispatchable power (the capability to draw power when needed) pose significant hurdles. These challenges necessitate adopting a hybrid energy system combining non-dispatchable sources like PV solar and wind with dispatchable options such as battery storage, gas-to-power and nuclear power. These facilitate a just energy transition from Eskom’s coal fleet. However, the viability of nuclear power is contentious due to its environmental and financial implications, despite its lower carbon emissions compared with gas and fossil fuels.
Utilising a hybrid system, with renewables as the primary energy source and gas-to-power or nuclear as backup, would ensure a constant dispatchable energy supply and committed base load capacity 24/7, reducing carbon emissions significantly while addressing the core issue of reliable energy access.
Is there a case for nuclear in South Africa?
South Africa’s capacity to build and sustain nuclear power plants is marred by excessively high construction costs and the time it takes to build a plant – on average, 10 years. The environmental risks associated with nuclear have also seen many local and international stakeholders try and fail to gain a foothold for more nuclear in South Africa.
It is heartening to witness South Africans shaping their energy future through their opposition to potentially environmentally damaging solutions and the growing recognition of the gravity of climate change and environmental degradation.
Illustrative cases revolve around the Karpowership environmental saga and a 140 MW wind farm project. The wind farm project was shelved due to cost considerations related to Eskom and Transnet and the ecological risks posed to birdlife in the area. Despite its potential to create employment opportunities for 1,500 individuals, the decision was substantially influenced by the presence of endangered bird species in the vicinity. A year-long monitoring effort revealed the birds’ flight path intersected with the area designated for the planned turbines. Turbines are known to pose a threat to avian life. Consequently, the initial plan to construct a 140 MW wind farm had to be downsized to 30 MWs, rendering the project financially unviable. These examples highlight the intricate balance between economic development and environmental preservation.
Exploring the potential for nuclear energy in South Africa, an alternative path emerges for smaller, modular nuclear reactors with capacities ranging from 100 to 150 megawatts. These compact reactors offer cost-efficiency, accelerated construction timelines and a diminished environmental footprint. Nevertheless, the prevailing anti-nuclear sentiment leaves the feasibility of this option shrouded in uncertainty.
Grid constraints and the Smart Grid option
South Africa’s grid infrastructure is constrained, necessitating a reconsideration of energy distribution. A ‘behind-the-meter’ approach offers the most viable solution for large energy consumers like the mining industry. By taking control of their energy generation and consumption, mining and other sectors can secure a reliable power supply and alleviate the strain on South Africa’s overloaded grid.
A behind-the-meter system allows such industries to integrate green energy sources, such as PV solar and wind (with or without battery storage), with other energy sources. Until dispatchable energy sources such as natural gas become accessible and deployable, PV solar, wind and batteries will interface with Eskom substations with energy distribution managed intelligently via hybrid inverters. This approach enables operational flexibility to entities like mines and production facilities, enabling them to switch between self-generating power and Eskom’s supply seamlessly, contingent on demand and renewable energy availability.
This benefits Eskom by allowing for the reallocation of grid capacity to other regions or municipalities, generating additional revenue for the national utility.
In the future, large industries may opt for energy autonomy, becoming Eskom-independent and deploying their mix of non-dispatchable and dispatchable power solutions behind the meter, which could potentially encompass liquid natural gas or modular nuclear solutions and/or battery energy storage.
Such hybrid solutions hold the promise of meeting South Africa’s energy demands with significantly reduced emissions when compared with coal-fired power stations. Nevertheless, the just energy transition away from coal remains a gradual process, with government policy likely to maintain coal reliance until the nation’s coal mines reach their natural end.
Available energy options in South Africa
Examining the available energy options in South Africa, PV solar emerges as the preferred renewable solution due to the country’s abundant sunlight. Wind energy, although promising, faces challenges associated with location and wind intermittency. Hydroelectricity’s long-term viability is hindered by climate change-induced drought and water scarcity. And while energy storage via batteries is on the rise, high costs currently render PV/battery solutions economically less appealing. In the future, when battery storage becomes more cost-effective, PV and batteries will become ubiquitous.
Green hydrogen
Green hydrogen, a promising dispatchable energy source for South Africa, represents a long-range solution requiring substantial research and development. The logistics surrounding hydrogen, encompassing its capture, transportation, and storage, warrants meticulous consideration. Its volatility and high flammability further underscore the imperative of prudent planning.
For electricity generation, extensive R&D is necessary to adapt gas turbines to accommodate hydrogen combustion. A notable drawback is the prodigious water consumption in green hydrogen production. Even though regenerative, it is a matter of paramount concern in a nation grappling with water security issues.
Natural gas
Liquid natural gas (LNG) occupies a transitional niche between renewables and fossil fuels. While less environmentally benign than wind, solar and green hydrogen, carbon emissions from LNG are substantially curtailed compared with fossil fuels.
In conclusion, South Africa’s energy crisis necessitates a multifaceted approach characterised by innovation, collaboration, and balanced consideration of the unique demands of industries, environmental concerns and the well-being of future generations, who are dependent on our present determinations. Such an all-encompassing strategy transcends mere preference. It represents the sole trajectory towards a sustainable energy future in South Africa. In the short to medium term, the accent should be on renewables with gas-to-power dispatchability. In the long term, green hydrogen holds promise, contingent upon rigorous assessment of water resource sufficiency.