The New York State Energy Research and Development Authority (NYSERDA) and the U.S. Department of Energy (DOE) confirmed last month the successful outcome of field trial testing of Beacon Power’s scale-power flywheel frequency regulation system in New York. At the same time, the New York ISO, which operates the state’s electric power grid, found Beacon’s technology to be viable for grid connection.
Flywheels have generally been regarded as highly reliable ride-through power sources, suited to providing a few seconds of electricity to bridge periods between the loss of grid power and full deployment of backup power. In recent years, technology advances such as carbon-fiber composite materials have allowed flywheel systems to broaden their role by providing megawatt-scale power for minutes or even hours.
One application of that extended capability is frequency regulation for grid support - something all utilities and/or grid operators must provide. With increasingly tight reserve margins, higher fuel prices and more stringent emission restrictions, traditional operators have found such grid support to be an even more onerous chore than it has been in the past.
Frequency regulation is necessary because the amount of power generated and the amount consumed must remain closely balanced at all times. When imbalances occur, the electric frequency (60 hertz in the United States) required by end users is not maintained and grid stability is compromised. Grid operators buy frequency regulation services on a continuous basis every day. In 2006, the value of regulation services purchased by five U.S. regional grid operators in open power markets exceeded $650 million, while the total market (including regulated regions) was $2 billion.
In parts of the U.S. where power markets remain regulated, utilities continue to provide frequency regulation services on their own. In areas where power markets have been deregulated, the task of frequency regulation falls to regional system operators and the regional transmission operators (RTOs) and independent system operators (ISOs). Those regional authorities must decide how much frequency regulation is needed, who provides it and at what cost.
Providing frequency regulation is a task that doesn’t come naturally for power plants because they have to ramp up and down to do it. That can mean more wear and tear on turbines and boilers. One way or another, frequency regulation also requires additional generation. Furthermore, frequency regulation typically accounts for 1 to 2 percent of all the power generated within a control area. Eliminating that task from the generating fleet would free up an equivalent amount of generating capacity.
In May 2005, Power Engineering reported that testing was underway in California and New York on flywheels deployed in clusters that could offer an alternative to the traditional method of using power plants to provide frequency regulation for grid support. The formal field trial of a flywheel-based frequency regulation system at a California substation has now been successfully completed. Beacon’s New York-based flywheel demonstration system was installed in March 2006 and began its formal field trial in June. The goal there was to determine the flywheel’s ability to provide fast-response frequency regulation, as well as another ancillary service called reactive power. Those scale-power tests were at kilowatt scale.
“Now we want to scale that up to megawatts and serve the grid,” says Gene Hunt, director of corporate communications for Wilmington, Mass.-based Beacon Power, which developed the Smart Energy Matrix grid support flywheel technology.
“We are now designing a 25 kWh flywheel with a 100 kW motor, which is much, much larger in terms of energy density than any other flywheel. We have a prototype that we’ve spun up to full speed, and we’re finalizing that design and expect to go into production in the second half of this year. When interconnected in a matrix, our flywheels will deliver megawatts for minutes, allowing them to provide frequency regulation to the grid.”
The Smart Energy Matrix is being specifically designed to address a sizeable and growing market with better performance and greater cost effectiveness than existing methods, says Hunt. Carbon-fiber composite technology allows high speeds (16,000 rpm) which can supply kilowatts for hours. By linking flywheels together in a cluster, the flywheel matrix plant can produce megawatts. “We have shown this can be done at a California substation, where our demonstration system completed 18 months of testing. During a formal field trial over a six-month period, we had 97.5 percent availability. The California ISO has certified our technology as ‘grid ready.’ Now that we have validation of our demonstration system, we’re looking for a location to build our first commercial-scale frequency regulation plant.” The 20 MW plant would be located in a 20,000 square-feet building containing 200 flywheels.
It’s not just growing demand for power in general that’s driving the need for an essential ancillary service usually provided by fossil-fired units. Adding to the growing need for frequency regulation is the addition to all grids of wind and solar generation, both of which are highly variable and intermittent. Adding so many variable sources of power compounds the need for more regulation support.
At present, Beacon plans to deploy its flywheels to sell frequency regulation services rather than sell the equipment itself. This is because the bidding structure for regulation services as managed today by the regional operators provides a great deal of potential for profit, especially if, as Beacon believes, it can leverage its much lower cost structure.
In the bidding process for frequency regulation bids are stacked based upon how much regulation will be needed for the day and providers submit their best price. The grid operator puts the low bidders at the bottom and stacks them up to the level where they get the amount of regulation needed. Whichever bid puts them over the top - whatever the top price is - becomes the price everyone in the stack gets paid.
That works well for the flywheel approach because without fossil fuel or scheduled maintenance costs Beacon figures it would be a low-cost provider, allowing them to bid aggressively and enjoy a high level of market participation. And the price paid to all bidders will be driven by higher-cost providers who have to allow for added operating, maintenance and fuel costs associated with providing regulation capacity. That should result in very attractive gross margins for Beacon.
The flywheel matrix systems can be sited almost anywhere because there are no on-site fuel needs and no on-site emissions.
“This should make it possible to site and build a plant in less than one year,” says Hunt. He adds that there is an emissions savings because greenhouse gas emissions are reduced by up to 90 percent.
“It’s not 100 percent because there is some power lost in the process - about 15 percent.”
Flywheels are like mechanical batteries. In the California test, a signal from the ISO arrived every four seconds and the flywheels was able to respond within one second. The FERC requirement is for utilities to respond within five minutes.
By contrast, the New York test system responded to frequency variations that it sensed through its direct grid connection. In addition, in cooperation with the New York ISO and a utility, the system also successfully demonstrated its ability to provide reactive power, a secondary service that the grid requires to maintain stability.
Hunt says the company is also talking to other open markets and ISOs. The plan is to provide this as a frequency regulation service rather than as part of a traditional model of building and selling a product to a utility. He believes the qualification and interconnection process for gaining grid and market access to sell services to an ISO or RTO is much faster than selling equipment to a regulated utility through the traditional procurement process. Not that owning a flywheel plant doesn’t make sense for a power company. The environmental and performance advantages can be compelling.
“It’s not a power plant where it takes you years to get the permits and licenses. It’s a clean-running, sustainable system that can provide the service while also lowering a utility’s carbon footprint. Our plan is to build a 10 to 20 MW plant in 2008, and more plants after that. We have not chosen the first site yet, but obviously California is one possibility.”-Steve Blankinship
