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### Pumped Storage Hydropower: A Key to Green Energy Transition
#### Part 1: The Role and Technology of PSH
Overview of PSH
Pumped storage hydropower (PSH) is a proven technology and a crucial tool for storing excess electricity generated during periods of low demand. It involves two bodies of water at different elevations. During low energy demand periods, surplus energy is used to pump water from a lower reservoir to an upper reservoir. When demand rises, water is released back into the lower reservoir through a hydro-electric power station to generate electricity.
Types of PSH
- Open-Loop: One of the reservoirs is connected to a naturally flowing water source.
- Closed-Loop: None of the reservoirs are connected to an external water source.
Global Capacity
PSH provides over 90% of all stored energy globally, with a total capacity of 179GW as of 2023.
UK Market
The UK has four operational PSH plants – Dinorwig, Cruachan, Ffestiniog, and Foyers – with a combined storage capacity of 32GWh. These plants have been operational for decades, with the oldest one, Ffestiniog, in operation since 1963.
#### Part 2: Renewed Interest and New Developments
Renewed Interest
The acceleration of the green transition is driving renewed interest in PSH. With the phase-out of coal-fired power stations and the increasing reliance on renewable energy, long-duration energy storage solutions like PSH are crucial to balancing intermittent energy supply.
New Projects
There is a considerable pipeline of new PSH projects in the UK, which could boost installed capacity by 6.9GW and offer 135GWh of storage. Notable projects include:
- Coire Glas: 1.5GW
- Cruachan 2: 600MW
- Loch na Cathrach: 450MW
- Glen Earrach Energy: 2GW facility at Balmacaan Estate
- Loch Fearna: 1.8GW project
- Balliemeanoch: 1.5GW scheme at Loch Awe
International Markets
China, Japan, and the US are leading in PSH capacity, with Australia also investing extensively in PSH projects like the 2.2GW Snowy 2.0 in New South Wales.
#### Part 3: Challenges, Future Outlook, and Economic Impact
Utilizing Existing Infrastructure
Repurposing abandoned mines for PSH projects can be beneficial, as these sites often have existing infrastructure, grid connections, and other necessary services in place. Examples include the Dinorwig PSH in Wales and the Kidston Stage 2 in Australia.
Challenges
Despite its importance, the number of PSH projects worldwide remains relatively low. Key challenges include:
- High Costs and Complexity: PSH projects are costly and involve long planning periods and multiple interfaces.
- Risk Mitigation: Effective risk mitigation measures are crucial to attract private investment and avoid delays.
- Government Policy: Supportive government policies and market support are necessary for the successful development of new PSH projects.
Economic Impact
More PSH projects will not only drive change in the energy market but also have the potential to transform local economies. For example, in Scotland, proposed PSH projects are expected to create thousands of jobs and bring significant economic benefits, similar to the transformation seen in the Highlands following the development of hydropower in the 1940s.
Cap and Floor Mechanism
The introduction of the cap and floor mechanism by the Department for Energy Security and Net-Zero in the UK is seen as a critical step in unlocking private investment. This scheme provides revenue support to developers and sets a threshold for gross annual margins, thus mitigating financial risks and encouraging investment.
Support Measures
Additional measures include removing regulatory barriers, streamlining licensing processes, and providing physical infrastructure support, such as access roads.
### Conclusion
Pumped storage hydropower is an essential component of the global green energy transition. Its ability to store excess energy and provide reliable electricity supply makes it a key enabler of a sustainable future. By addressing the challenges and leveraging existing infrastructure, the development of new PSH projects can be accelerated to meet the growing need for energy storage. Additionally, the economic benefits of such projects can significantly contribute to local and national economies, marking a transformational shift in the energy landscape.