On a holiday trip to Mull over the Easter weekend, I called in to Cruachan Power Station near Oban. As a power engineer, it’s a place I have always wanted to visit and it didn’t disappoint.
Built into the hollowed out rock of Ben Cruachan, the turbine hall of this pumped storage hydro power station is accessed by a 1km tunnel. The four 110MW reversible turbines are powered by water from a 10 million cubic metre storage reservoir built 400m above the machine hall.
One of only four pumped storage stations in the UK, Cruachan was the first to use reversible turbines, where electricity is used from the grid at times of low demand to pump water from Loch Awe to the storage reservoir in readiness to generate at times of peak demand.
In this respect, Cruachan works like an enormous rechargeable battery and plays a vital part in soaking up variability in electrical demand from consumers and delivering the flexibility necessary to deal with the peaks and troughs
of the growing renewable energy sources.
But will the stability that stations such as Cruachan bring to the grid be capable of being maintained as Britain builds yet more wind or solar farms? Well, it is certainly going to be challenging, especially given the cost and lead times for building additional conventional hydroelectricity capacity.
So it is likely that there will need to be more flexibility in the power sources available to keep the lights on in the face of increasing renewables’ intermittency, and this will doubtless lead to opportunities for innovative solutions.
One option might be the burgeoning development of battery technology. Driven by advances in the electric vehicle market, battery costs have plummeted to a level that makes mass battery back-up a reality. As a result, there is a flurry of just completed, ongoing or planned large-scale projects.
Various different approaches abound, from research to further increase the life of lithium-ion batteries to applying older technologies in a more efficient way and completely novel technologies. Current trials are under way around the country from Shetland and Gigha in the north, Larne in Northern Ireland and Leighton Buzzard in the south.
All this is leading to a rapidly growing role for batteries with predictions of at least 1GW being available, although thinly spread, within the next four years.
Perhaps batteries will therefore not quite replace the need for another one or two Cruachans in the short term, but there is no doubt they will in the longer term. When this happens, they will support the in excisable rise in the place of electricity and electrical infrastructure in our society. As you have heard me saying many times before: “The future is electric!”
Managing Director, SELECT