Beacon Power Corp. Flywheels to Help New York Grid Stability

Load control strategies and concepts:
– Stability
– Frequency regulation
– Voltage regulation
– Load leveling
– Power quality

FastCompany
Large scale power storage can be extremely helpful for maintaining a stable power grid. One of the important load control strategies is "frequency regulation." Grid controllers can maintain the power frequency of the grid within acceptable limits by absorbing or releasing a portion of the supply energy to the grid, as needed.

To ensure a functional and reliable grid, the Independent System Operators (ISOs) that operate the various regional grids must maintain their electric frequency very close to 60 hertz (Hz), or cycles per second (50 Hz in Europe and elsewhere). When the supply of electricity exactly matches the demand (or "load"), grid frequency is held at a stable level. Grid operators, therefore, seek to continuously balance electricity supply with load to maintain the proper frequency. They do this by directing about one percent of total generation capacity to increase or decrease its power output in response to frequency deviations.

...Over the last decade, Beacon Power, in conjunction with the U.S. Department of Energy (DOE), California Energy Commission (CEC), the New York State Energy Research and Development Authority (NYSERDA), and various ISOs, has developed an advanced flywheel-based energy storage technology to perform fast-response frequency regulation. _Beacon

The US DOE has finalised a $43 million loan guarantee to Beacon Power Corporation for installation of a 20 MW flywheel storage system in Stephentown, New York, for purposes of frequency regulation of the power grid.

Beacon’s Gen 4 flywheel system is specifically designed to perform frequency regulation on utility grids by absorbing and discharging energy to balance power generation and consumption on the electric grid. The technology operates by using flywheels to quickly store and release from the grid in order to follow rapid changes in grid demand.

Flywheel-based regulation is fast and efficient, ramping up or down 10 times faster than ramp rates for conventional fossil fuel generators that typically perform this service.

Beacon estimates that a 20 megawatt flywheel-based frequency regulation plant will reduce carbon dioxide emissions up to 82% over its 20-year life compared to a coal, gas or pumped hydro plant. The flywheel plant also does not emit air pollutants such as nitrogen dioxide or sulfur dioxide. _GCC

Flywheel storage has extremely low energy density, which prevents flywheels from being effective for other purposes of grid stabilisation such as significant load leveling. And in terms of emergency power backup, flywheels are only effective for a very short period of time, before backup gas generators or other backup can be brought on line.

List at top excerpted from: Load Control System Reliability presentation

This development is being touted as a means to reduce CO2 exhaust, but in reality this effect is not even a drop in a bucket. The continued improvement of high-tech flywheels is one important component of a total power grid and emergency power backup picture, however. A very small part, but an important part nonetheless.

Can Flywheels Make Wind Energy Reliable?

Big wind energy suffers from a host of problems. Wind power is not baseload power -- it is too intermittent to rely on for routine daily loads. Wind power is not dispatchable -- it is unable to rise and fall at will in order to meet unanticipated loads and overages. Wind power is expensive -- without subsidies it would die outright. Wind turbines and gearboxes break down and must be replaced far more often than time-proven power sources -- at enormous cost.

Can flywheels help?

One of the big challenges for solar or wind power is that they are intermittent, not constant. The sun only shines half the hours at best (not even counting clouds or rain), and similarly, the wind does not blow continuously. To make these energy sources more practical, efficient power storage is necessary; you need to be able to top up the “battery” when the power is on and then use it to provide electricity at night, on overcast days, or when the air is still.

As reported by the New York Times Monday, a Massachusetts company thinks it has a solution to the problem of energy storage: flywheels.

A flywheel is a nothing more than a heavy wheel that rotates or spins freely. If you connect it the right kind of dual-purpose electric motor—some electric motors, like the ones in hybrid and electric cars, can function as both motors and generators—you can use the motor to spin the flywheel up to speed when there’s a surplus of power. Then, when you need energy, you slow down the wheel and convert its momentum back to electricity. If the wheel is heavy enough and spinning fast enough—the ones that Beacon Power is installing near Albany, New York, weigh a ton each and spin up to 16,000 times a minute (267 times a second)—you can store an enormous amount of energy in them. _Source

Flywheels themselves are untested at the scales that they would be needed for large-scale wind farms and solar facilities. They are mechanical, and more prone to breakdown than a solid state form of storage would be. They are expensive. Flywheels may help with dispatchability -- load leveling -- but they cannot correct for extended periods without wind.

Small and medium scale wind power can be quite useful for particular niche applications and for off grid. Large scale wind and solar are markedly inferior to nuclear and clean coal in virtually every way -- but particularly in terms of reliability.

Al Fin power engineers like the concept of the flow cell battery for utility scale load leveling, once the bugs are ironed out. Such an approach would have to be paired with gas turbines, and would be extremely useful as long as the baseload power was provided by nuclear, enhanced geo, or clean coal / biomass.

Flywheel Energy Storage at Supersonic Speed

Beacon Power Corp. says it has a better idea: massive rotating flywheels that store power like giant alkaline batteries spinning at twice the speed of sound. _BostonGlobe

Flywheel storage stores energy in kinetic form--rapidly spinning wheels, ready for almost instant tapping in case of power failure. But the problem with them is their lack of energy density: they simply cannot hold enough backup energy for more than a short period of time. Rotating energy is defined by its mass and rotational speed. Beacon's flywheels weigh 2500 pounds, but it is Beacon's higher speeds that pack the power:

Beacon Power flywheels are 2,500-pound cylinders made of carbon fiber and fiberglass, and bonded with epoxy. Each is mounted on bearings that generate a magnetic field to support the flywheel, so it floats inside its steel casing. Friction is almost nonexistent. When the flywheel is spun to its full speed of 16,000 revolutions per minute, it can store the energy for hours with little loss.

"The surface speed on this thing would be Mach 2," or twice the speed of sound, Capp said. But these flywheels don't generate a sonic boom, because they operate in a vacuum to reduce friction even more.

At the base of each flywheel is a motor-generator system like those found in hybrid cars. When electricity is added to the system, it acts as a motor, speeding up the rotation. To release power, the system acts as a generator, translating the rotation to electric power and feeding it into the grid....Each flywheel can store enough power to run a typical US home for a full day. But they cost $200,000 apiece, and while Capp hopes to cut the cost to $100,000, they're still far out of the average consumer's price range.

Instead, Beacon Power hopes to address a constant nuisance for electric utilities: precise regulation of power.

...Beacon Power plans to build storage arrays, with dozens of flywheels buried underground inside vaults made from concrete sewer pipes.

A standard shipping container stuffed with computers and power cables controls the array and links it to the electrical grid.

When there's extra power available, Beacon Power would buy it and use it to spin the flywheels. When the grid needs an extra burst of juice, the flywheels can convert the stored energy back into electricity, which is resold to the power network.

"You can almost think of it as recycling electricity," said Gene Hunt, company spokesman. Beacon Power would make its profit by charging a fee for its power regulation service.

Utility load leveling is an incredibly important task. Without utility-scale storage devices, power distribution can be extremely tricky and prone to errors.

In safety terms, it is a good idea for them to bury these massive speedy spinners underground in strong concrete vaults. I wouldn't want to be around when one of these giant tops explodes.

More at MarketWatch

Can you find the error in this NextEnergyNews article?

The company currently building a massive commercial scale system that is capable of storing 5 million watts of power.

Absolutely right! One can supply 5 mega watts of power, but one cannot store 5 mega watts of power. One stores mega watt hours, not mega watts.

Better Large Scale Battery Storage

Al Fin is always spouting off about the need for "utility scale energy storage" for load-leveling, and for bringing more renewable energy sources online--such as solar and wind. Al Fin's favourite technology is the redox flow cell, but other storage technologies are making a bid to play this very important role.

Using so-called NaS batteries, utilities could defer for years, and possibly even avoid, construction of new transmission lines, substations and power plants, says analyst Stow Walker of Cambridge Energy Research Associates. They make wind power — wildly popular but frustratingly intermittent — a more reliable resource. And they provide backup power in case of outages, such as the one that hit New York City last week.

Such benefits are critical, because power demand is projected to soar 50% by 2030 and other methods of expanding the power supply are facing growing obstacles. Congress is likely to cap carbon dioxide emissions by traditional power plants to curtail global warming. Meanwhile, communities are fighting plans for thousands of miles of high-voltage transmission lines needed to zap electricity across regions.

....American Electric Power (AEP), one of the largest U.S. utilities, has been using a 1.2 megawatt NaS battery in Charleston, W.Va., the past year and plans to install one twice the size elsewhere in the state next year. Dozens of utilities are considering the battery, says Dan Mears, a consultant for NGK Insulators, the Japanese company that makes the devices.

"If you've got these batteries distributed in the neighborhood, you have, in a sense, lots of little power plants," Walker says. "The difference between these and diesel generators is these batteries don't need fuel" and don't pollute.

The NaS battery is the most advanced of several energy-storage technologies that utilities are testing. The oldest and most widespread form of energy storage in the USA, pumped hydroelectricity, collects water after it spins a turbine and uses a small amount of electricity to send it back and repeat the process.

Lead-acid batteries — the same kind used in cars — were installed by Southern California Edison in 1988. But the batteries, though inexpensive, typically fill warehouse-size buildings and last about five years. That's because the acid that connects positive and negative electrodes corrodes components.

An NaS battery, by contrast, uses a far more durable porcelain-like material to bridge the electrodes, giving it a life span of about 15 years, Mears says. It also takes up about a fifth of the space. Ford Motor pioneered the battery in the 1960s to power early-model electric cars; NGK and Tokyo Electric refined it for the power grid.

Since the 1990s, Japanese businesses have installed enough NaS batteries to light the equivalent of about 155,000 homes, says Brad Roberts, head of the Electricity Storage Association. In the USA, AEP is using the 30-foot-wide by 15-foot-igh battery to supply 10% of the electricity needs of 2,600 customers in north Charleston, says Ali Nourai, AEP manager of distributed energy. The battery, which cost about $2.5 million, is charged by generators from the grid at night, when demand and prices are low, and discharged during the day when power usage peaks.

....A more intriguing goal is to wring more energy out of the wind farms that are cropping up across the country. Wind typically blows hard at night when power demand is low, producing energy that cannot be used. When demand peaks midday, especially in the summer, wind is often sporadic or absent. NaS batteries could let AEP store wind-generated power at night for daytime use.

Next year, AEP plans to install another NaS battery in West Virginia to provide backup power in case of an outage — the first such application of the technology, Nourai says. The battery would kick in automatically, so customers would see no disruption.

Other utilities are planning or considering the technology. In Long Island, N.Y., a group of utilities plans this summer to install an NaS battery at a bus depot. The battery is charged at night, when power prices are low, and discharged during the day to pump natural gas into tanks to provide fuel for the buses, says Mike Saltzman of the New York Power Authority. That cuts electric costs for the bus company and eases stresses on the grid. Pacific Gas & Electric is leaning toward installing a much larger, 5-megawatt battery by 2009, enough to power about 4,000 homes, says PG&E's Jon Tremayne.

....Meanwhile, other storage devices are gaining traction, too. A group of Iowa municipal utilities plans to use wind turbines to compress air during off-peak hours that will be stored in an underground cavern. The air would be released at peak periods to run turbines and generate power for about 200,000 homes. Another technology, the flywheel, has a massive cylinder that can spin for days after being started by a generator. The cylinder can then activate a turbine to supply electricity for a few seconds or minutes when it's needed, for instance, to head off an interruption to a computer center from a lightning strike.

Source

Homes, businesses, neighborhoods, and larger areas all need energy storage scaled to their needs. This is one of the more important energy issues at present, yet it gets relatively little attention.

Hat tip Fatknowledge blog