Could we find places for more pump-up hydro storage?

[Bob Wallace]

At this point in time pump-up hydro is our cheapest way to store electricity.  Pump water up with spare electricity, let it flow back through turbines when we need electricity. 

We've got over 20 GW of pump-up in the US that we installed back when we were building nuclear reactors.  There's no way to turn them off when we don't need the power so we built pump-up to carry late night surplus power to daytime peak hours.

It's not uncommon for people to claim that there are no more places to build pump-up.  They usually claim the tree huggers wouldn't allow it.  (And, lots of us would object to damming any more streams.)

But how about converting some existing dams to pump-up.  Might there be a couple we could use?

There's a 1997 study of existing dams on federal land.  The researchers were interested in seeing if any were potential power producers.  They looked at 871 existing dams and screened them for adequate hydraulic head (enough pressure to run a turbine), stream inflow, reasonable distance from transmission lines, outside of protected areas, etc.  They found that 6 had hydro generation potential.  That together they could produce 1,230 MW.  Enough power for 957,000 residences

http://www.usbr.gov/power/data/1834/Sec1834_EPA.pdf

Luckily they posted a list of all 871 dams in the appendix, along with dam height/head.

I worked my way through the first 212.  Out of that 212 sample 29% (61) had at least 50' of head.  9% (19) had at least 100' of head.  And 4% (eight) had at least 190' of head.
 
In the US we've got around 80,000 existing dams.  We use about 2,500 currently to produce electricity.  That leaves us with approximately 77,500 candidate existing dams.

Using the federal dam percentages we might expect 22,475 with greater than  50' of head.  6,975 with greater than 100' of head. And 3,100 with greater than 190' of head.

Potentially thousands of existing dams usable for pump-up storage. 

Almost all dams (every dam I've ever visited) has a set-aside safety zone below it. 

Go a short distance from the dam and excavate a '2 to 5 day hole'.  A large enough basin to hold the water that would be used for generation over the longest period in which the wind and Sun let us down. 

Install a pump/turbine combo between the two reservoirs. 

Run wire.


 

[Jim Hunt]

Hi Bob,

In brief, yes. Here's the UK perspective on energy storage in general:

http://www.energyresearchpartnership.org.uk/dl291

Edited highlights:

Grid-scale pumped hydro storage for electricity production in the UK has a volume of 27.6GWh.

SSE has proposed two new 30GWh schemes, which could be completed by 2017/18 at the earliest.

There is limited space to expand pumped hydro storage in the UK, so other options for storage need to be explored.

According to the Global Energy Network Institute in

http://www.geni.org/globalenergy/research/energy-storage-technologies/Energy-Storage-Technologies.pdf

Pumped hydro plants, so far, is considered to be the only possible way to store energy in a huge amount while maintaining a high efficiency and being economical as well and has about 98 percent share of total global storage predominant in today’s grid.

For a novel take on the principle see also their reference to Eduard Heindl's "Hydraulic Hydro Energy Storage"!

Basically, the idea is to cut out a large cylindrical body of rock and lift it hydraulically using hydro pumps to force water underneath it. The body would rise several hundred meters if completely charged and would sink into the ground again during discharge.

[ghoti]

Other alternatives for pumped storage include unused mines and mined out quarries. Here's an article about a proposed quarry conversion to pumped storage.

http://www.theglobeandmail.com/report-on-business/industry-news/energy-and-resources/in-eastern-ontario-a-battery-five-times-the-size-of-niagara-falls/article8820070/

There really isn't a shortage of spots which have already been ecologically destroyed waiting to be redeemed for the greater good.

[Bob Wallace]

Thanks for that link.  Germany is also pursuing abandoned mine pump-up hydro.

We might want to consider using some of the destroyed mountains in coal country for closed-loop hydro.  There's plenty of water to charge the system.  It would create jobs where they are being lost as the coal industry dies. 

A nice fat UHVDC line could transport power to/from the heavily populated eastern seaboard.