
As you know, we’ve had many days, weeks, of electricity supply from wind power at well over the 100% demand level. However, we remain susceptible to the Trumpian critique that we cannot rely on wind every day, even in Scotland.
Battery storage is showing signs of accelerated development that will lead to it being at least a partial solution:
£20 million Scottish renewable energy storage unit for Broxburn will be first in UK
First battery-powered hotel in UK is in Scotland
However, it seems unlikely that battery storage will be enough, so recent developments in pumped storage look interesting. From Energy Voice, yesterday:
‘The developers of a Highland pumped storage project claim their technology is tailor-made to fill the supply gap left by offshore wind. The developers of the 450 megawatt (MW) Red John project in Inverness, last night described the need to meet the potential energy gap as “urgent”. As the most advanced site in Scotland, the Red John project could generate enough electricity to power over 400,000 homes.
From Red John (no relation)
‘UK wind developers were paid £125 million in curtailment charges last year alone – in other words, they were paid not to produce electricity. Our plans will go a long way to help get the maximum benefit of new renewable energy for the country and the environment.’
https://www.energyvoice.com/otherenergy/194339/highland-pumped-hydro-could-fill-offshore-wind-gap-claim-developers/
From an earlier report here explaining how this technology would work, see:
‘In the last couple of years, there has been a growing a number of news articles and blog posts published about energy storage, particularly in the form of battery systems. This interest is very reasonable, and the news is exciting because these systems can fill in wind power and solar power electricity production gaps. However, it appears as though pumped hydro storage is being overlooked, with all the hype about batteries. It still has huge potential to help balance clean, renewable energy. In fact, all the discourse about battery storage seems to be supporting the idea that this form of storage is going to solve clean energy intermittency issues, but there are gaps in what batteries can provide, so let’s take a look at pumped hydro so we can see just how large a factor it could become.’
https://cleantechnica.com/2018/03/04/no-huge-energy-storage-breakthrough-needed-renewable-energy/
‘Pumped hydro storage’ is, as far as I can see, the same thing as out long-established hydroelectric power stations, such as the one at Cruachan. Here’s how the US system is illustrated:

I’m no technologist so is it just a hydroelectric power plant of the kind we have decades of working with? If so, why is this technology not being talked about for storage? My first reaction is that perhaps our hydroelectric power stations generate all the power they need by themselves to pump water back up for storage. There may however be other sites which would need the electricity from renewables to achieve their full storage potential. I don’t know. The US report suggests that there are potentially around 22 000 pumped hydro energy sites in Australia and that Germany already has plans to use the technology to store around 23Gw by 2050 so there must be something in this.
Finally, of course, there are environmental and safety concerns with battery storage while hydro is, to my knowledge, safer and more ecologically sound.
As in some earlier pieces, this is a social scientist dabbling in the physical sciences and technology, but I know some readers are equipped to clarify or correct.