Beacon Power produces a novel
form of power storage in the shape of large carbon fiber flywheels, which
spin at 16,000 revolutions per minute -- a surface speed of about Mach 2.
At one meter in diameter and 8,000 lbs, each wheel can provide 100 kilowatts of
electricity for 15 minutes.
The company, led by CEO William Capp, is packaging 10 of the flywheels together
to give an impressive power output of 1 MW and energy storage capacity of 250
kilowatt hours. With the average household consuming approximately 8,900
kWh yearly, this would be enough to power a home for over 10 days.
The new technology isn't just about the high energy costs, either -- it can
help provide backup power in case of a storm. Utilities and businesses
could adopt the devices to minimize interruptions to customers during storms or
On the environmental side of things, the device could complement intermittent
power sources such as wind power and solar power, and use their stored
output to avoid incurring extra cost or outages during periods of peak demand.
Says Capp, "These are used for fine tuning to keep everything in balance.
The way it's done today is that a dispatcher sends a signal to generators...to
increase or decrease output."
The device is extremely simple on a most basic level. Adding electricity
spins the wheel faster. At any time this spin can be converted via a
generator to power. Over time, the wheel slows, but this is a very
gradual process. The technology is among the novel storage technologies
being considered for use with alternative energy products. Another
promising technology is molten
solar power, which stores solar heat in a briny fluid, for power production
in nighttime hours.
However, the flywheels are more promising in a way, in that they can deal with
daytime peaks as well. Capp says that utilities will buy them to help
them fulfill emissions restrictions regulations stating, "Rather than
generating the power using fossil fuels, we'll be recycling the energy."
The company is marketing plans currently for 20 MW storage facilities,
consisting of 20 one megawatt units.
quote: Why doesn't everyone get all uppity when a space-related article mentions astronauts in "zero G" or "weightlessness"?
quote: I had no idea that capacitors such as this even existed.
quote: The formula for energy stored in a flywheel is 1/2 I w^2, where I is the inertia of the wheel, and w is the rotational velocity (radians per second, although you can convert that to RPM easily enough.) So the inertia is important, but the speed is even more so, because of the squared term.
quote: Carbon fiber has among the highest strength to weight characteristics of modern materials (okay, diamond is better ...)
quote: On a side note, I remember flywheels like this (but smaller and faster) being proposed for automotive applications. There were some really interesting problems to tackle with precession (a 20k rpm flywheel makes a hell of a gyroscope... picture a car that won't turn or pitch up and down...)
quote: The company is packaging 10 of the flywheels together to give an impressive power output of 1 MW and energy storage capacity of 250 kilowatt hours. With the average household consuming approximately 8,900 kWh yearly, this would be enough to power a home for over 10 days.
quote: Adding electricity spins the wheel faster. At any time this spin can be converted via a generator to power. Over time, the wheel slows, but this is a very gradual process.