Sunday, July 6, 2014

Pumped hydro – the forgotten storage solution : Renew Economy

hydroStorage is in the energy news now, in more places than can be listed.
To pick a few, here is recent news from Europe,Tesla, and Queensland.  Everyone is looking to the day when battery technology can economically partner with the popular yet variable renewables: solar PV and wind.
But what if today there was a proven way to store vast amounts of energy at capital costs lower than what battery technologists hope they might achieve in 20 years time? A technology with high round-trip efficiency and one heck of a lifespan: 85 years and counting!
If you have read this article’s title, then you know where we are going with this: pumped hydro.
You may know, in energy terms, pumped hydro can be enormous (the Bath County Virginia facility with 3 GW of generation capacity and 30 GWh of stored energy is said to be the “world’s largest battery”), or niche (the 11 MW El Hierro pumped hydro facility, partnered with wind, now makes that Canary Island 100% renewable).
Possibly you already know that pumped hydro – with 140 GW of generation capacity installed globally – dwarfs all other forms of frequently and deeply cycled, on-purpose energy-storage technologies such as batteries, compressed air, flywheels, molten-salt-thermal storage, or synthetic chemicals created to store energy, combined!
Why? Because for so long pumped hydro has been the cheapest. At the University of Melbourne Energy Institute (MEI) we surveyed literature costs for pumped hydro projects globally and found capital costs as low as $100 to $200 capital per kWh of useable energy stored. Chemical battery makers are aiming for costs in the range of $200 to $500 capital per kwh (useable) to be on the market in 2025.
Due to this technology-cost gap and other factors such as the growing penetration of renewables, you may know pumped hydro is resurging globally: in China and Europe, and it is again being considered in Japan, Canada, and the US (California, Hawaii, North Carolina, and even in the desert state of Arizona.)
You may know Australia already has three large-scale pumped hydro facilities in Queensland and New South Wales, operating for more than 30 years: Shoalhaven (240 MW), Wivenhoe (500 MW), and Tumut 3 (600 MW).