19-08-2021 | | By Robin Mitchell
Recently, the UK Government announced a new competition that could see winners be granted up to £1m during the first phase winners and £11m during phase two. Why is energy storage becoming important, what types of energy storage exist, and how will such competitions help develop such technologies?
Since the development of the first power stations, one of the main challenges that grid operators faced was ensuring that the electrical supply remained steady and stable. During peak power consumption times, power stations have to increase their output to meet this demand so that the voltage and frequency remain constant. The same applies to when demand decreases, whereby power stations need to reduce their output.
This coordination is more intelligent than one would think, and the power station does not decide to change the output power of a power station. Since different energy sources take time to change their output power, sudden demand changes are met using power sources that quickly respond. For example, gas power can react almost instantly to a change in demand, but nuclear energy takes hours to respond. Thus, slow-reacting power sources such as nuclear are often kept at the same output while other power sources react to changes in demand.
Now that the world is trying to move towards renewable energies, new energy challenges have never affected electrical distribution. One of these challenges is the need for sizeable energy storage so that electrical power can be taken away from the grid and fed back in during times of changing demand.
The specific reason why energy storage is needed is that the two major types of energy generation, solar and wind, are unpredictable and cannot be adjusted. If power demand is low, the energy generated by renewables can be wasted with no adverse effects. Still, if demand for power increases and renewable sources are already operating at 100%, the demand cannot be met.
As such, energy storage will enable renewables to store energy when they produce more power than what is required. The stored power can then be fed back into the power grid when demand increases and renewables cannot meet this sudden demand.
When it comes to storing excess energy, there are many types, but typically fall into one of two categories; potential energy storage and chemical energy storage. Potential energy storage is those that move mass from a low height to a high elevation. One common variation is pumped water storage that carries water to a higher reservoir during peak energy generation. This water then returns to the lower pool through a turbine during peak energy demand.
Another form of energy storage using potential energy is the stacking of concert blocks using cranes. During peak energy generation, a crane lifts concrete blocks from the ground onto a stacked structure of other concrete blocks. These blocks are lowered to the ground using a cable that pulls on a dynamo during peak energy demand.
Chemical energy storage is commonly achieved with the use of large rechargeable batteries (typically lithium-ion). The same technology is already used in small-scale solar and wind installations for providing a few kWh of energy to a small home. This technology also powers most electric vehicles to date, thanks to its energy density and ability to offer large currents.
Recently, the UK Government announced a new competition to challenge the industry into developing new innovative energy storage solutions. The competition ties in with the government plan to increase renewable energies while also trying to achieve net-zero carbon emissions by 2050.
Those interested in the competition have until the 14th of August to apply, and entries must not use existing technologies that have already been commercialised (such as lithium-ion and pumped hydro). A successful proposal will be awarded up to £1m during the first phase, and if selected again during phase two, can expect up to £11m.
While it is not stated why commercial solutions will not be accepted, it is most likely that the funding secured by the Government is for research purposes only. Commercial solutions that already exist can continue to be developed by companies, but it can be challenging to get funding to develop a new idea or method. As such, the competition will enable researchers and engineers to think outside the box concerning energy storage.