Researchers in the Energy Institute at the University of Sheffield are pioneering a dynamic energy storage system to better balance the UK electricity grid, leading to fewer power cuts, more efficient energy use and a more sustainable energy system for the UK.
As the UK transitions to more sustainable forms of energy, the grid is being supplied by 1000s of wind, solar and other power sources dotted around the country. This has made matching demand and supply challenging. When the sun is shining or the wind is blowing a surplus of energy can be generated, but on still or cloudy days there may not be enough to meet demand.
Therefore sophisticated energy storage systems that can capture energy surpluses are essential to the UK’s ability to decarbonise the grid system and meet its goal of net-zero greenhouse gasses by 2050.
Professors Dan Gladwin, Martin Foster and Dave Stone from the Energy Institute and the Department of Electronic and Electrical Engineering are developing a system that enables much faster, more flexible reactions to the UK’s changing energy demands than the current systems in place, reducing the risk of power outages.
The main type of short-term energy storage used on the grid is battery storage, where in the last five years the capacity installed on the UK has grown from a few pilot projects to over 900MW. These battery systems are used to deliver continuous power to help balance the grid on a second-by-second basis but also to store power over longer periods of time. Batteries suffer from degradation, meaning that as they are used their capacity and efficiency decreases, they also have to have their temperature carefully managed, this can limit the availability of the system.
Flywheels are a technology that can provide a very fast response and at high power, although they do not store as much energy compared to batteries. However, flywheels do not suffer from degradation and can operate at full capacity for 25 - 50 years with minimal maintenance. Standalone flywheels for grid energy storage are an emerging technology, and although there have been some trials around the world, the reliability of the systems have either not been successful or the installation costs have been prohibitive for commercialisation.
The AdD HyStor project oversees the design and piloting of an innovative flywheel system that has similar installation costs to that of batteries and that have increased reliability and low maintenance costs. These flywheels are adaptable in their design to adjust for the amount of power and energy required. The AdD HyStor project develops a hybrid energy storage system that uses the batteries and flywheels to create a flexible system that optimises the use of the two types of energy storage.
The hybrid system, having been first tested in Ireland, is now installed at the University of Sheffield’s grid testing facility at Willenhall near Wolverhampton. It comprises a 2MW/1MWh battery and a 600Kw / 10kWh flywheel system making it the largest hybrid battery-flywheel storage system in the UK. The team are demonstrating the system to show how it can exactly match the requirements of energy demand and usage and offer a more stable energy system for homes across the country.
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 760443
