Exploring the feasibility of pumped hydroelectric energy storage (PHES) using seawater in South Africa

5e21c4b7-e8e5-483d-b291-1c11999127a5

Active

Innovate UK
Innovate UK
Innovate UK
Innovate UK
Innovate UK

£1,048,360

March 31, 2023

June 30, 2024

South Africa is currently facing its biggest ever power crisis with many parts of the country facing rolling blackouts of up to 6-hours/day due to an inability to consistently meet demand which results in daily load shedding. This is severely impacting businesses and households, limiting economic growth and further deepening an unemployment crisis, currently at a staggering 34.5%.

In response, South Africa's government has committed to transforming the Energy Sector. A key part of this goal is centered around Renewable Energy investment and a move away from coal which currently accounts for 70% of energy supply, with a target of 17800 MW of electricity to be derived from renewables by 2030\. However, for this to be achieved it needs to be accompanied by an effective means of energy storage.

This project aims to address this current barrier through the initial development of a 11 GWh pumped hydroelectric energy storage (PHES) using seawater as the storage medium, with the potential to be scaled further. Although seawater PHES is not new, it has not been attempted at large-scale with key challenges (e.g., saltwater corrosion, biofouling, impact on marine life) to be addressed. However, with the acceleration of renewable-investment programmes and increasing demand on freshwater reserves, a number of seawater projects are currently being considered in other locations including Australia and Chile.

Replicating the same set-up of freshwater PHES (energy storage achieved by pumping water to an upper reservoir when energy is abundant and then generate electricity during peak times by releasing the water to the lower reservoir in this case the sea, therefore reducing capital cost) but with planned innovations in filtration techniques, dam lining and through the use of floating solar panels to reduce evaporation, the UK-based Africa New Energies (ANE) Limited, seek to overcome legacy challenges to offer a solution that can increase and further demonstrate the viability of seawater-PHES globally.

Successful outcomes from this 9-month feasibility study will give confidence to move into detailed design and financing. Once operational from 2025, the proposed solution will deliver significant socio-economic and environmental impacts across South Africa including:

* Support the case for Renewable-Energy investment as the country seeks to move from its coal dependency.
* New employment opportunities.
* Provide greater grid stability.
* Improve security of supply and affordability.
* Reduce the need for freshwater use in a country recognised for its aridity.
* Annual CO2 savings of 1.96 million tonnes.
* Replicable knowledge and model.