Flexible energy storage solutions are the key to our renewable energy future
Why do we need energy storage?
The UK power industry is experiencing unprecedented change, with the proportion of electricity generated nationally by renewable technologies rising sharply each year, whilst generation by traditional fossil fuel plants has dropped sharply. This has largely been driven by a significant reduction in the use of coal, which has fallen from nearly a third of electricity generation in 2014 to just 5% in 2018. The drop in overall fossil fuel generation has been aided by higher renewable generation, particularly from wind, solar which has nearly doubled since 2014, accounting for 21% of generation in 2018.
Renewable energy generation however, can be intermittent and volatile, and the UK electricity grid therefore needs to deploy flexible energy generation and storage technologies in order to guarantee a reliable supply of clean electricity to consumers and provide a storage mechanism in times of oversupply so the network is balanced. In other words, if the wind is blowing at times of low electricity demand and producing a large amount of energy, we need to be able to store this energy and call upon it at times of high demand so as not to fall back on polluting fossil fuels. Flexible generation and storage technology is absolutely critical in order that the UK can achieve its target of cutting carbon emissions to almost zero by 2050
A brief history of hydro-power
Hydro power is essentially using the force of water and gravity to create kinetic energy. Earliest evidence comes from India in the 4th Century BC, following which it was refined by the Roman’s to turn grain into flour and the Chinese Han Dynasty to pump water to irrigate their crops. This has evolved into the huge dams we have all over the world today, strong enough to hold back vast amounts of water and release this to produce equally vast quantities of energy on demand.
Pumped hydro: A simple and effective solution
Pumped hydro takes this concept one step further, by utilising reversible turbines that can pump water back up, storing energy and in effect acting as a giant battery. In short you take an upper and a lower reservoir and connect the two via a tunnel. This means that at times of high electricity demand water can be released down through the turbines generating electricity which can then be sold and when demand is low, the turbine will pump water back to the upper reservoir, recharging the energy store for later use.