The Project
The Earba Storage project is a proposed pumped storage hydro (‘PSH’) scheme with an installed capacity of up to 1,800MW.
The Earba project will be the largest such scheme in the UK in terms of energy stored.
Pumped Hydro Storage
The Earba PSH project will store up to 40,000MWh of energy which will make it the largest such scheme in the UK in terms of energy stored. The impressive generation capacity and energy storage figures are matched by the site characteristics which are ideal for a pumped storage hydro project. This includes the geology and topography around the existing lochs which are natural ‘bowl’ shapes, and therefore allow straightforward modification to form upper and lower reservoirs which will blend sensitively into the local landscape. The National Grid transmission network is in close proximity to the site and there is excellent existing road access.
Pumped Hydro Storage
The Earba PSH project will store up to 40,000MWh of energy which will make it the largest such scheme in the UK in terms of energy stored. The impressive generation capacity and energy storage figures are matched by the site characteristics which are ideal for a pumped storage hydro project. This includes the geology and topography around the existing lochs which are natural ‘bowl’ shapes, and therefore allow straightforward modification to form upper and lower reservoirs which will blend sensitively into the local landscape. The National Grid transmission network is in close proximity to the site and there is excellent existing road access.
CO2 SAVINGS AND LOCAL EMPLOYMENT
The Earba Storage development would be a major civil engineering project. It is anticipated that the construction period would last approximately five years and the workforce would average approximately 500 people on-site throughout this construction phase.
The development of the Earba Storage project will bring multiple benefits to the country both in terms of a clean energy supply and savings to the electricity consumer. The large amount of energy stored by the project means that it will both store significant amounts of surplus wind energy, which would otherwise be lost, and displace conventional gas generation and hence reduce emissions. The proposed scheme has the potential to rapidly supply clean electricity to the national grid, powering over 1,400,000 UK households and saving over 2 million tonnes of CO2 annually.
The Location
The proposal is to use Loch Leamhain as the upper reservoir and Loch Earba as the lower reservoir.
A tunnel approximately 3km long will connect the two water bodies.
A powerhouse will be constructed on the shore of Loch Earba which will extend deep underground. The turbines will be located at the bottom of the powerhouse shaft and will generate electricity in times of national demand or pump water for energy storage in times when there is surplus electricity on the national grid.
Why is Earba a great PSH project?
To make a meaningful difference to the UK system, significant additional capacity in terms of both power (measured in MW or GW), and stored energy (measured in MWh or GWh) is required. Sudden significant increases in generated or absorbed power are often required: for example when weather patterns change, in emergencies such as when a nuclear power station trips, or when a sporting event results in big changes in demand, such as when a world cup football match goes into half-time. But fast-reaction power increases or decreases are only part of the solution.
As the UK transitions away from a system dominated by large on-demand thermal generation, to one dominated by intermittent renewables it becomes increasingly challenging to balance the grid. Weather patterns especially wind, rather than the daily changes in demand, become the dominant factor. To balance longer consecutive periods of low wind or high wind (which can last many hours, or even days), long duration energy storage is required. Large-scale, long-duration energy storage ‘LLES’ is typically understood to mean anything above 4hrs duration but our analysis suggests at least 12hrs storage is required in order to provide an optimum balancing service to the grid. So along with power, large quantities of energy are also required.
The Earba PSH project ticks both boxes:
It provides both significant quantities of power (up to 1,800MW) and stored energy (up to 40GWh). In fact when compared with other PSH projects it scores very highly.
The chart below shows the power and stored energy ratings of Earba (orange dot) compared with the four existing operational PSH projects in the UK (blue dots) and any PSH projects in development (green dots). Earba’s position on the upper, right-hand part of this chart shows it to be one of the biggest and best PSH development projects in the UK.