By Sherwin Harris, Renewables Lead at ENGIE
It is no secret that South Africa faces challenges with energy generation and capacity. There is a growing focus on investment into cleaner, less carbon-intensive energy that can be fed into the grid to boost the much-needed power supply that the country needs.
Renewable energy has been pinpointed as one of the most efficient and cost-effective solutions to allow the move away from fossil fuel-based power systems to a net-zero carbon economy by 2050. Globally, there is a massive push towards amplifying decarbonisation efforts – and countries that fail to show their commitment to a low-carbon energy transition are likely to face an increasing trade risk through measures like carbon taxes.
There is a silver lining for South Africa: the renewable energy opportunity in the country is immense. It has world-class endowments of resources such as solar and wind and as a consequence green hydrogen.
However, at the heart of the country’s ability to unlock the real value of these renewable energy resources lies battery energy storage – due to its dispatchable nature it allows for energy to be stored and delivered in usable form whenever it is needed.
By their nature, solar and wind forms of power are variable and intermittent – they fluctuate so cannot reliably produce energy, so when they do, this output needs to be stored so it can be dispatched when it is required.
The key to reliable renewable energy is battery storage. It is the glue that holds together a renewable energy-dominated power mix. Harnessing the most efficient and cost-effective batteries to store and dispatch the energy produced by renewables presents far-reaching opportunities and benefits for South Africa. The most notable of these are:
- The reduction of loadshedding
- Increased economic output by providing a reliable energy supply – supporting and enabling broader economic growth
- Energy cost reduction due to energy arbitrage – by charging the battery during off-peak time periods and discharging the battery during peak periods
- Enabling renewables to be operated as dispatchable assets
- Supporting the move to decentralised energy generation and microgrids, which will enable faster electrification
- Increasing the penetration of lower cost green renewables by reducing the variability associated with renewable generation
- Reducing the country’s dependence on diesel
- Enabling a local battery manufacturing industry that is able to supply South Africa and other African markets
Finding the right battery for the right needs
Considerations around benefits differ according to the needs of customers, for instance: at a utility scale asset an important objective is achieving the best cost per kilowatt-hour (kWh) and the best performance guarantees for Battery Energy Storage Systems (BESS) to alleviate technical and operational risks of battery projects. At a Commercial and Industrial (C&I) level, the key is energy cost reduction through energy arbitrage, and at a residential level, customers are most concerned with buying the right battery at the right price to mitigate the impact of loadshedding.
Lithium phosphate batteries are currently the most efficient and cost effective for short and medium duration storage of renewable energy across the spectrum because of their cost per kWh and energy density – the amount of energy that can be stored per battery unit. This means more energy can be stored per battery no matter the size, ensuring it can run for longer and unlocking greater value.
Nickel Manganese Cobalt (NMC) batteries overtook lead acid batteries as one of the most popular options for solar storage –due to their high energy density. However, safety concerns have emerged recently due to the relatively unstable nature of cobalt. Lithium Iron Phosphate (LFP) batteries have gained in popularity as they are safer and more stable, and the materials used are less expensive than in NMC batteries.
Flow batteries, Sodium ion and Liquid Metal batteries are gaining ground as viable options – each with advantages based on customer needs. Flow batteries have the ability to deliver a consistent amount of energy over a longer period, whereas Sodium ion and Liquid Metal batteries are both low-cost and safe, with long lifespans.
Customers – whether residential, or at C&I or utility scale – need to consider their unique needs and make a decision based on what is most competitive and suited to their requirements.
Ultimately, renewable energy underpinned by solid battery energy storage is a long-term solution to South Africa’s energy supply and generation challenges. Energy storage is the silver bullet that will help South Africa unlock the value of renewable energy to drive stability in the energy supply and boost economic growth.