into the grid
technology from Beacon Power Corporation could be the gateway for
renewable energy producers
to seamlessly tie into the grid, and the first live connection of a
grid-scale flywheel energy storage system is now operating in New York
The consistent supply of electricity is like a high wire balancing act
between supply and demand. A greater influx of power from renewable
sources to power grids can disrupt that balance. However, along with
new, economical ways to generate renewable power, new tools are being
invented to seamlessly connect the producer with the consumer.
Power's technology has been approved for use on five of the six power
grids in the United States, and the first live connection of a
grid-scale flywheel energy storage system is now operating at a
frequency regulation plant in Stephentown, New York.
new short duration energy storage technology developed by
Massachusetts-based Beacon Power
Corporation may prove invaluable for plugging renewable power sources
into the grid as well as providing a stronger safety net for
consistent, reliable power to consumers.
called a flywheel energy storage system, and it has the ability to
convert electrical energy to kinetic energy and back to electrical
energy in a matter of seconds, without the use of fossil fuels. Its
main purpose is to provide power grid frequency stability in a more
responsive, cheaper, and environmentally friendly way than is currently
provided by power plants.
technology hinges on a fairly straightforward scientific principle
known as the first law of thermodynamics, which states that energy can
neither be created nor destroyed but can only be converted from one
form to another. This is exactly what the Beacon Power flywheel does as
electricity demand fluctuates.
of Beacon Power's Smart Energy 25 flywheels is a vertical cylinder
measuring about seven feet high and weighing about 8500 lbs. It
consists of a high performance rotor assembly that is sealed in a
vacuum chamber, which spins at between 8,000 and 16,000 rpm. At 16,000
rpm, the flywheel can store and deliver 25 kilowatt hours of
extractable energy. The rotor is enclosed in a vacuum to reduce
friction and energy losses. To reduce losses even further, the rotor is
levitated with a combination of permanent magnets and an
electromagnetic bearing. The units can be interconnected to multiply
storage capacity and are installed below ground in a concrete
Beacon Power holds over 60 U.S. patents involving its technology and
about a dozen international patents. It's also the only player offering
this flywheel technology at a grid application level.
of Beacon Power's flywheels is a vertical cylinder measuring
seven feet high and weighing about 8500 lbs. It consists of a
performance rotor assembly that is sealed in a vacuum chamber, which
spins at between 8,000 and 16,000 rpm. At 16,000 rpm, the flywheel can
store and deliver 25 kilowatt hours of extractable energy.
"It's based on a straightforward principle that's as old as an ancient
potter's wheel," says Gene Hunt, Beacon Power's director of corporate
communications. "What makes this different is the use of
technologically advanced components that did not exist 10 years ago."
Among these are carbon-fiber composite materials, advanced
semiconductors and other electronics, hybrid magnetic bearings, and
motor-generator designs that allow for extremely fast response to
control signals with high efficiency.
It has taken some time for Beacon Power to develop its technology to
its current level. The company was founded in 1997 with the goal of
developing advanced flywheel-based energy storage technology. Its first
and second generation systems were deployed in North America for
back-up power in the telecommunications industry. However, as that
market slowed and with positive feedback from both the U.S. Department
of Energy as well as the PJM Interconnection (one of the largest grid
operators in the world), Beacon Power redirected its research and
development program to develop a new generation of flywheel products
aimed at "recycling" electricity from the grid to perform an essential
grid stabilization service.
While consumers perceive a steady stream of electricity, the reality is
that power supply and demand are fluctuating all the time, with peak
demand generally occurring during the day and lowest demand when people
The public is largely unaware that there are a number of stabilizing
services that are needed to ensure a constant electrical balance on
each power grid at a stable 60 hertz (Hz) or cycles-per-second
frequency. That balance is maintained by signals sent by grid operators
like PJM Interconnection to power generators to maintain, boost, or
decrease power supply based on supply and demand.
Current energy storage systems can take up to five minutes to respond
to a signal from grid operators to boost or reduce power production.
The Beacon Power flywheel has captured the attention of both the
conventional and renewable power generation and distribution community
because of its ability to absorb or discharge power for as long as 15
minutes and to respond to the grid operator's control signal in under
The technology has been approved for use on five of the six power grids
in the United States, and the first live connection of a grid-scale
flywheel energy storage system is now operating at a frequency
regulation plant in Stephentown, New York. This first installation,
which is providing 14 megawatts of flywheel energy storage cost about
$69 million to build. A second frequency regulation plant that Beacon
Power is planning to build into the PJM grid is expected to come in at
about $52 million, and the cost for a third installation is expected to
fall even lower. At full capacity, Beacon Power's Stephentown plant
will provide 20 megawatts of regulation service to the New York power
grid, or approximately 10 percent of the state's typical daily demand.
The New York grid is controlled by the New York Independent System
Operator (NYISO), and it sends out signals to absorb or inject power
every six seconds. The Beacon Power installation at local utility
provider, NYSEG's substation in Stephentown is now one of the resources
it calls upon to balance supply and demand.
full capacity, Beacon Power's Stephentown plant will provide 20
megawatts of regulation service to the New York power grid, or
approximately 10 percent of the state's typical daily demand.
Beacon Power earns revenue from the use of its installation, and
revenue will increase as the installation ramps up to its full 20
megawatt regulation service capability. That was expected to be by May.
By connecting 10 of its Smart Energy 25 (Gen 4) flywheel energy storage
units, Beacon Power is able to generate one megawatt of power. So at 20
megawatts, the Stephentown facility will eventually consist of 200
"Fossil fuel plants can take up to five minutes to respond to a signal,
meaning that by the time such a conventional resource has fully
responded to a particular up or down signal, another 50 control signals
could have been sent," says Hunt. "This means that fossil fuel plants,
bulky and slow moving as they are, will sometimes find themselves
actually going in the opposite direction of where the grid operator
wants them to."
While the Beacon Power flywheel technology is not a long-term solution
for power storage for alternative technologies such as wind and solar,
it could be the gateway for renewable energy producers to seamlessly
tie into the grid. Hunt says that as more intermittent generation
resources are added to the grid, there will be greater and more
frequent imbalances between demand and supply, which needs to be
constant at a tightly regulated 60 hertz and can be forecast and
controlled in today's power generation environment.
However, he adds that maintaining a supply and demand balance will
become less predictable when renewables reach 10 percent or 20 percent
penetration. "With greater imbalances between supply and demand, there
will be a doubling or even tripling in the need for regulation. That's
where our technology can play a role—providing
fast-responding regulation capacity at high efficiency without
emissions or fuel consumption."
That ability to stabilize renewable power flow to the grid is already
being demonstrated in California, which has set a target of achieving
33 percent power production from renewable resources by 2020.
Power's first installation in New York State, which is providing 14
megawatts of flywheel energy storage, cost about $69 million to build.
Subsequent plants are expected to come in at a reduced cost.
Beacon Power has installed a flywheel energy storage system
demonstration project at a wind farm in Tehachapi, California, in
collaboration with the California Energy Commission, California ISO,
and power utility PG&E. The application of the technology is
somewhat different than the New York installation, which was focused on
frequency regulation. The concept in California is to demonstrate how
the flywheel can be used as a safety valve between local sub-station
lines and wind power producers. In this situation,
‘intelligent agent' controls are used to demonstrate how it
is possible to enable as much wind-generated electricity to be
delivered as possible without exceeding the limits of the locally
constrained transmission system. At times when the local
sub-transmission line is constrained because of a lack of delivered
power or thermal overload, the intelligent agents (provided by a
company called Alternative Energy Systems Consulting working with
Beacon Power) will override its regulation function and order the
flywheel to operate temporarily as a full-scale commercial system. It
would return to its frequency regulation role once the constraint is
The goal is to demonstrate that this flywheel system can deliver value
to the grid operator in addition to frequency regulation. The Tehachapi
area of California has been identified as a high potential wind
resource by the California ISO, with as much as 4200 megawatts of wind
power possibly being added in coming years.
"This was the first Gen 4 flywheel that we shipped, installed, and
operated outside of Beacon's facility, and it went very smoothly," says
company president and CEO, Bill Capp. "It's also the first of our
systems intended to show how energy storage can help to optimize the
output of a wind farm."
Beacon Power is also pursuing sales of turnkey flywheel storage
systems. The company's main targets
for selling turnkey implementation of its technology are power
companies that provide both conventional and renewable power in the
closed, or vertically integrated, electricity markets in North America