| Someone check my working here: "bigger than an Olympic-size swimming pool" - not helpful but I'll assume not much bigger, or they'd compare it to something bigger - so 2.5 ML (million litres), pumped 200 m against gravity with 2.5 x the density of water, in MWh: (2.5e6 * 2.5 * 9.81 * 200) / (3600e6) = 3.4 MWh. That's: - about 5 minutes feeding the 50 MW turbine,
- most of an hour replacing the output of a large (10 MW) wind turbine at typical capacity factors,
- about 0.03 % the capacity of Dinorwig (I believe the UK's largest hydro plant),
- 1 - 2 tonnes CO2 emissions from a natural gas peaker plant,
- the usage of about 3 - 5 g of typical nuclear fuels.
- don't know or care about coal, sorry. If you really want to avoid using gas or nuclear in the UK, and not freezing pensioners, I'd be looking at storing the order of 1-2 TWh. I'll bet that the best competition for water is just building more wind turbines than you need. Any working fluid that doesn't literally fall from the sky just won't scale, and is at best a distraction. Yes, fluid. I'll note an interesting relation between global nuclear deaths and global hydro storage deaths. |
I did a back of the napkin calculation on this, assuming the article meant 7 GWh. That'd require roughly 4 pools per installation (assuming 50m x 20m x 2m for one). However the article is constantly mixing up energy and power.
I think it has debunked many times that gravity storage may solve our energy storage needs. Gravity is just to weak for that. You literally would need to move mountains for that.