Stories
Slash Boxes
Comments

SoylentNews is people

posted by Fnord666 on Wednesday March 08 2017, @11:43AM   Printer-friendly
from the won't-it-float? dept.

Pumped storage is a decades-old technology with a relatively simple concept: When electricity is cheap and plentiful, use it to pump water up into a reservoir above a turbine, and when electricity is scarce and expensive, send that pumped water down through a turbine to generate more power. Often, these pumped storage facilities are auxiliary to other electricity-generating systems, and they serve to smooth out fluctuations in the amount of power on the grid.

A German research institute has spent years trying to tailor pumped storage to ocean environments. Recently, the institute completed a successful four-week pilot test using a hollow concrete sphere that it placed on the bottom of Lake Constance, a body of water at the foot of the Alps. The sphere has a diameter of three meters and contains a pump and a turbine. Much like traditional pumped storage, when electricity is cheap, water can be pumped out of the sphere, and when it's scarce, water can be let into the sphere to move the turbine and generate electricity.

The Fraunhofer Institute for Wind Energy and Energy Systems Engineering envisions spheres with inner diameters of 30m, placed 700m (or about 2,300 ft) underwater. Assuming the spheres would be fitted with existing 5 MW turbines that could function at that depth, the researchers estimate that each sphere would offer 20 MWh of storage with four hours discharge time.

https://arstechnica.com/science/2017/03/german-institute-successfully-tests-underwater-energy-storage-sphere/


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 3, Informative) by khallow on Wednesday March 08 2017, @03:31PM

    by khallow (3766) Subscriber Badge on Wednesday March 08 2017, @03:31PM (#476479) Journal

    What kind of pressure would be exerted on a hollow sphere at 700m deep?

    The pressure exerted by a column of water 700 meters high. A column of water a little over 10 meters high exerts one atmosphere of pressure on the bottom. So we're speaking of a bit under 70 atmospheres of pressure (68 atmospheres to be more accurate).

    Also, how much force is applied by buoyancy when it's empty?

    The weight not mass of the water displaced by the sphere minus the weight of the sphere when empty. Enough high density steel in the sphere (5-6 times more dense than water) and it could be made with neutral or negative buoyancy.

    Starting Score:    1  point
    Moderation   +2  
       Informative=2, Total=2
    Extra 'Informative' Modifier   0  

    Total Score:   3