Significant growth in the capacity of variable wind and solar generation technologies and inflexible nuclear power stations in UK is crucial to achieving a net-zero electricity system by 2035 and a net-negative electricity system by 2050. Decarbonising the transport sector and a greater reliance on electricity for heating are expected to increase electricity peak demand further. The growing use of variable renewable energy sources for power generation poses several challenges to the operation of power systems, in particular, supply and demand imbalances. Currently, the GB power system relies on significant input from gas-fired and hydro-electric power stations for balancing peak demand. Further, 13 GW of new electricity storage is required by 2030 to balance the 34 - 77 GW of new wind and solar generation. Existing technologies for grid-scale energy storage have their own pros and cons in terms of cost, life cycle environmental impacts, and scalability. Tidal Range Schemes (TRSs) are renewable generation technologies that can also be operated as grid-scale energy storage facilities. This is a unique feature of TRSs which has not been investigated significantly and is the key focus of this project.
TRSs, such as tidal lagoons and barrages, generate renewable electricity by creating an artificial head difference between water levels on the seaside, driven by tides, and water levels inside the basin, controlled by flow through the structure. TRSs have a significant advantage over many other forms of renewable energy generation in that they are based on a highly predictable resource. Electricity generation has been traditionally considered as the primary goal of TRSs and they are mainly designed to maximise electricity generation. However, such schemes - particularly with pumping - can be highly controllable and therefore can be used as energy storage facilities. There are a number of tidal range schemes at different sizes proposed in UK coastal waters, with several other sites being investigated. One of the barriers to TRS development is their relatively high capital cost (but typically connected to a long capital cycle). This leads to a high expected cost of electricity generation. However, operating TRSs as energy storage facilities enables them to increase their revenue through price arbitrage and providing ancillary and reserve services. This consequently makes the TRS business model more financially viable while supporting the operation of the electricity system. The capability of TRSs to function as grid-scale energy storage facilities can be enhanced by new approaches to design and operate TRSs. It is also crucial to consider techno-economic and life cycle environmental impacts of TRSs being utilised as storage facilities compared to other grid-scale storage technologies.
In this proposed project, we will investigate the optimal design and operation of TRSs as configurable grid-scale energy storage. This also includes an economic assessment of the revenue of TRSs when they are utilised as energy storage, and techno-economic and comparative life cycle assessment of TRSs and other common storage technologies in order to provide a better understanding of the potential impacts of TRSs.
The proposed project is formed of 6 work packages which are closely connected. The project team will be working with an Advisory Board to ensure that project will respond to the key challenges related to the utilisation of TRSs as grid-scale energy storage facilities as highlighted in the proposal and benefit a wide range of stakeholders.