Flywheels Coming Online for Power Storage
by Lloyd Alter, Toronto on 01.19.07
The idea of using flywheels as energy storage medium has been around for a while; this gyrobus tooled around Switzerland in the early 50's. In the 80's volvo played with a sort of hybrid, with a small diesel engine charging the flywheel. The big flat wheels held a lot of power but the rim spun at 3,000 RPM and there was some concern about what would happen in accidents or malfunctions.
As John mentioned in his earlier post, flywheels can be used to smooth out short-term variations in demand at power plants, which makes them more efficient, or more importantly,can be ganged together for storing energy from variable sources like sun or wind. Last week the California Energy Commission was impressed, saying "California has made a significant commitment to deploy renewable energy placing greater demands on the state's electric grid. Technologies such as Beacon's flywheel-based energy storage system provide attractive options." after studying a prototype 100Kw system packed into a shipping container.
"Housed in a transportable shipping container, the basic Smart Energy Matrix is a compact frequency regulation services system that could be located nearly anywhere on the grid. The system is remotely controlled and monitored for maximum flexibility. Depending on operator requirements, it could be placed at or near a substation or within the distribution system, where additional benefits such as voltage regulation, backup support, or reactive power could be provided for even greater value. Scale-power versions of this system are being demonstrated now in California and New York."
We really like the fact that the flywheel is tall and narrow rather than flat and wide, and that it is nicely encased in a solid steel cylinder- storing all of that electrical energy as kinetic energy can be a dangerous thing, which is why we probably won't see too many new gyrobuses or gyrocars. But what a great idea for wind and solar! ::Beacon Power thanks to ::Stilgar at Hugg
Interesting technology and very promising indeed. Another technology that makes renewable energy more and more attractive.
Dupe: http://www.treehugger.com/files/2006/08/load_balancing.php
Great article, but just thought I'd mention that energy is in units of joules or watt-hours, and that power comes in watts. The flywheels don't really store 20 MW, but I would love to find out how much energy they can in fact store. And how quickly they lose the energy to friction. Has anybody got the figures?
I think flywheels would do fine in cars and buses. No more dangerous than high power batteries and their chemicals. Just made sure the containment cylinder doesn't break easy.
Oh what's with the middle of the sentence starting a paragraph after the 3rd picture?
This would be a nice response to folks who snicker at wind or solar power, "What happens if it's cloudy? What happens if it isn't windy?"
Easy -- we store the power in our flywheel! :-)
There was a good article recently in Wired, which talked extensively about the Chysler race car project that supposedly used flywheel power. Turns out that they never got the flywheel to work very well, and in the race car promotional video the car was actually towed while the care was under "flywheel power". The project was terminated when someone was seriously injured by an exploading flywheel.
The seriousness of storing energy in kenetic form cannot be over emphasised. Mechanical failure under the kinds of stresses these flywheels have to undergo is more or less inevitable, something that their use in a vehicle makes much more problematic due to road shocks and vibration. (Google "expoding flywheel")
The City of Montreal tested a flywheel powered bus (one of several flywheel powered buses and trains) but the project was terminated after the flywheel exploded when the flywheel was being energized, despite being wrapped in a triple layer kevlar fragmentation containment shield designed to make failures safe. By the way, these flywheels spun at 20,000 rpm plus, which is necessary for suffiencent energy storage.
The article doen't mention why flywheels are so attractive despite their dangers. Because they are a fast rotating mass they can be made either a generator or a motor easily, or simultaniously in the case of a current regulator. Which is the reason why the small rotating mass created by the tall and thin design can work, it is effectively energized all the time to varing degrees. Which prompts the question not mentioned in the rather uninformative article; what are the losses of having this flywheel regulation in the loop? Regulation is an evil, but a necessary evil to make variable power sources like wind power usable. The key is to not waste too much power in the process.