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US pumped storage hydro project gets one step closer to build out

The entire industry seems to believe that Lithium Ion batteries are the be-all and end all of storing energy, but the truth is that pockets of resistance are capable of a handful of exceptions – at the lower end of the scale Vanadium flow has many commercial devotees, and at the higher end, Hot rocks, Liquid Air, and Molten Salt all have their fans – and pumped storage goes without saying, and yet there are so few live projects on the cards for pumped storage, that we felt developments in Montana were worth a mention.

A company called Absaroka Energy has managed to get a pumped storage development ready for take-off, and will fire the gun the moment it has a power purchasing agreement of some kind.

The uniqueness of the system is two-fold, first it is not part of an existing water system – so less permits need to be gone through, effectively it is a closed loop system and the water stays more or less in the system throughout apart from some evaporation and top up. It involves two reservoirs, one 1,000 feet vertically above the other, connected not by one two way, fixed-speed, reversible turbine which both pumps water up for charging or lets it fall back down for discharging. Instead it uses three separate pairs of turbines and pumps, so that instead of it taking 30 minutes to change from generating energy to pumping it up the hill, it can instead be changed in seconds- in fact both can happen at the same time.

It helps to know that this project has been around since 2008, when it was initially seen as part of a larger wind and transmission business, with 3,000 MW of wind farms, feeding the both transmission lines to California and the storage project. It never got built and has changed hands. This week Copenhagen Infrastructure Partners agreed to spend the $1 billion it needs to bring it to fruition – and once an offtaker can be found, it could go live as a project in 2020 and take just four years to build.

The output would be 400 MW of power capacity with over 8 hours of duration – so 3200 MWh and it could switch from output to filling up at a speed in keeping with any intermittent renewables.

But while this is a worthwhile story, we don’t see anyone rushing out to find similar propositions. It takes years to get the permissions, it only takes storage to about twice the size of current Vanadium or Lithium Ion project size, which can happen far more quickly, and it doesn’t leave those other technologies behind which offer 1 GW scaling. Siemens Gamesa told us very confidently about its hot rocks technology or ETES as it calls it, offering both direct heat for district heating projects and also energy storage as easy to switch on as a steam turbine.

The lost opportunity cost of the project sitting around for 11 years really makes this a bit of a nonsense as a future strategy for anyone other than Absaroka, although good luck to it for seeing it through this far.

So far Absaroka Energy has secured the site, obtained water rights and permits including a new hydro license for construction from the Federal Energy Regulatory Commission (FERC).

One report described the project as two swimming pools, 1,000 feet apart vertically, connected by a hose, and that approach, with the multiple pairs of turbines and pumps may well provide a reference site for any other similar situation on both public or private land and stimulate further uptake of pumped storage – but we remain to be convinced.

Clearly pumped storage hydro is a really great natural resource, but until governments ease permit laws it has too long a lead time and works in too few places to move the dial on energy storage. Hydro as a form of generation is creeping along at about 100 MW a year in the US, of which pure pumped storage is about 50 MW a year. It’s great if you have done the work, have the permits and are looking for an offtaker, but up to that point it is hard graft. Although the 21.6 GW of existing pumped hydro provides around 97% of utility-scale storage on the US grid, according to the National Hydropower Association, at the current rate of battery uptake that may (and should) change very soon.

The project says it will use a quaternary configuration of pump and turbine from GE Renewable Energy and act as a carbon neutral alternative gas peaker facilities at lower cost.

The Gordon Butte project is in Meagher County, three miles from Martinsdale and under six miles from an interconnection to major transmission lines.

Hydro has become largely unpopular due to environmental implications which usually translate into decades long development cycles.

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