Germany to Store Wind Power in Mountains

Sign up for daily news updates from CleanTechnica on email. Or follow us on Google News!

In an interesting marriage of clean and dirty tech, Deutsche Welle is reporting that the state government of Lower Saxony in Germany is looking into repurposing old abandoned coal mines inside the Harz mountains as pumped storage for wind power.

The idea has attracted approval not only from environmentalists in the region, who like the invisibility of the storage, but also from former coal miners, who like the idea of the disused coal mines being put to good use as a kind of “green battery” for wind power.

“The tradition of mining is so great in the Harz region, that they want to see the mines back in use again, so there are practically no critics of the project,” noted Marko Schmidt, an engineer for Lower Saxony’s Energy Research Center, who came up with the concept.

This acceptance is surprising to someone who has lived for so long in America, where green energy has to do battle, for different reasons, with both sides. Perhaps this pragmatic approach (when coupled with its uncomplicated embrace of green energy) is responsible for Germany’s economic growth.

Variations on ideas for pumped storage are surfacing now that the world needs to integrate intermittent wind power with the grid, but Schmidt’s innovative idea would be the world’s first use of an abandoned coal mine for this purpose.

Traditional pumped storage uses gravity to harness wind power. Water is pumped up a hill to a reservoir by wind power when it is available, typically at night, so that it can be released downhill when it is needed, using gravity to drive the turbines to make electricity.

In this case, the pumped water would be stored inside the mountaintop, rather than on it, in a reservoir, but it would still be high enough so that gravity could be used at the bottom to drive turbines when it is released. This would be a contained loop system, so the water does not contaminate rivers at the bottom.

Schmidt estimates that a pilot plant could be built in Bad Grund within the next three to five years for between 170 and 200 million euros, that would be large enough to provide up to 400 MW of storage capacity at a time, enough to power 40,000 households for a day.

Each typical windy night could be “time shifted” to power the following day’s daytime needs in this way, one day at a time. Schmidt also believes that there are up to 100 other sites in Germany that could be similarly utilized, simply by adapting the no longer used infrastructure of the fossil age.

Image: UGA

Have a tip for CleanTechnica? Want to advertise? Want to suggest a guest for our CleanTech Talk podcast? Contact us here.

CleanTechnica Holiday Wish Book

Holiday Wish Book Cover

Click to download.

Our Latest EVObsession Video

I don't like paywalls. You don't like paywalls. Who likes paywalls? Here at CleanTechnica, we implemented a limited paywall for a while, but it always felt wrong — and it was always tough to decide what we should put behind there. In theory, your most exclusive and best content goes behind a paywall. But then fewer people read it!! So, we've decided to completely nix paywalls here at CleanTechnica. But...
Like other media companies, we need reader support! If you support us, please chip in a bit monthly to help our team write, edit, and publish 15 cleantech stories a day!
Thank you!

CleanTechnica uses affiliate links. See our policy here.

25 thoughts on “Germany to Store Wind Power in Mountains

  • Fantastic idea. Lets hope this movement towards green energy gains even greater momentum.

    • yeah, awesome! the article was one of the 1st things I saw when I opened my email this morning — was a nice story to wake up to! 😀

  • Really cool idea! And even better, it’s a closed system! Imagine how much power that can be generated if they do the same on those other 100~ sites 🙂

  • Great use of the coal mines. Is the entire “system” contained internally within the mountain? I assume that the existing coal mine will be both the storage and the chute for the power system.

    • That was all I could get from my source. I had the same question. 

  • As my dad used to say, that is using your head for more than a hat rack.

  • This was done in New Jersey at least 3o years ago using I believe a lake, by Public Service and Gas Co.

  • I am sorry, my previous post about New Jersey’s energy storage failed to mentioned that it stored elecricity from off peak generation. Same idea though.

  • Pingback: Germany May Store Wind Power in Abandoned Coal Mines | Inhabitat - Green Design Will Save the World

  • Good to see you back Susan.

    This is an idea that has interested me for a while.  Mines are deep, they provide the sorts of elevation differential needed to make pumped solar work.  Mines frequently have flooding problems, so water shouldn’t be an issue.  And mines often have substantial grid connections, so at the minimum the route should be in place.

    By using an existing higher level side tunnel for the higher reservoir and  placing the pump/turbine at the lowest level they should be able to get these systems up and running in a hurry.

    • Thanks, Bob, good to be back. Yes, good points, as always. (Why don’t you write for our site? You always have such useful things to add.)

  • Storage may make wind more useful, but it further diminishes the effective output from, and increases the costs of, an already marginal source.

    • Storage does not “diminish the effective output” of wind, it moves output from where it’s not needed to where it is needed.

      Storage will increase the effective output of wind.  With storage there will be less curtailment of wind when demand is low, the surplus power can flow to storage and be used later when demand rises.

      And, yes, storage does add something to the cost of the electricity produced by wind and time-shifted for when it’s needed.  But since wind is already the least expensive (new) way we have to generate electricity it’s likely that stored wind will be competitive against gas peakers, the other way to make power on demand.

      • Perhaps I should not have used the term “effective”, which suggests the grid-planning term “effective capacity”. You are correct that storage would actually increase wind’s “effective capacity” as it would then be somewhat dispatchable. I simply meant that energy would be lost in the process of storage.

        • Sure, there’s a loss in putting energy into and taking it out of storage.  Probably in the range of 10% to 15%.

          The question becomes…

          How much does that loss raise the cost of the stored power and how does that cost compare to other power sources?

          If wind is being produced at a nickle and storage loss is 10%, then the cost of power coming out of storage is 5.5 cents plus storage cost.   If natural gas is a dime then it seems to make sense to install extra wind capacity and store power in order to avoid burning gas.

          Pumped-up stored energy is not ‘somewhat’ dispatchable, it’s very dispatchable.  The response time of turbines is incredibly fast.

          • It’s not dispatchable if there’s nothing there.

          • Bogus.

            Natural gas is not dispatchable if the pipeline is empty.  Flywheels are not dispatchable if they aren’t spinning….

          • With pumped hydro, the loss is more likely in the range of 20-30%.

          • There’s a new generation of pump/turbines which are more efficient.  We should see some new numbers soon.

            Some of the loss (~5%) in pumped hydro is evaporation losses which will not be an issue in closed loop systems inside a mine.

  • Woops, thanks, fixed.

  • this sounds like a fantastic development but do you have any view on cost – how does capitalisation of 5000 euro per household compare to other means of securing backup/reserve power?

  • Very Innovative Approach to store Wind Energy.

    Dr.a.Jagadeesh  Nellore(AP),India
    Wind Energy Expert

  • Pingback: Putting Damaged Land to Good Use | CleanTechies Blog -

  • Interesting idea. I think that finding new ways of thinking about existing infrastructures and institutions is a neat idea and a great way to prioritize the environment. can’t wait to see the development of this project!

    • I took a look to see if there has been any further work on this idea but found nothing on English language sites. I did find this bit of info –

      ” The United States has 80,000 to 250,000 retired mines wasting away that could be ideal sites for big renewable energy projects.”

      Along with some other interesting stuff –

      We’ve got over 70,000 existing dams and at least 10% should be usable for pump-up.

      In the UK they are turning an old rock quarry into a pump-up storage facility and Canada is working on using an old open pit mine.

Comments are closed.