ice or molten salt, not batteries, to store energy - battery energy storage system

WASHINGTON —
Energy storage is critical to turning the grid into a clean, sustainable, low-cost grid
Emissions systems, experts say.
It has happened, just not what most consumers expect.
The simplest idea of storage
When there is a lot of wind energy and there is not much demand for it, or when there is plenty of sunshine at noon, charge the battery --
According to experts, this is a viable few years. The reason?
It costs hundreds of dollars to store a kilowatt hour.
Battery energy per hour, while the national average retail price is kw-
About 11 cents an hour.
In the wholesale market, even on the off-site low buy
During peak hours and high-priced sales, battery owners may get 25 or 30 cents per investment of about $400.
Jay Apt, executive director of the Carnegie Mellon power industry center, said that "Storage is not profitable for such transactions . ".
The price will have to drop 90% from the current $300 to $500 per kilowatt
He said production capacity dropped to $30 to $50 an hour.
Instead, power companies and some commercial power users are adopting storage methods that many people don't think are batteries --
For example, place ice for large containers in the basement of a building or in a huge molten salt tank.
When using ordinary old batteries that store actual power on the grid, they do very subtle, high
Pay attention to work, such as keeping the AC system at the right rhythm, or smoothing the energy flow of wind farms that are prone to sudden start and stop.
On the horizon is an exotic future, where conventional and renewable energy capacity is sufficient, the installation of batteries requires a bridge of solar energy during the day.
California expects that when solar energy disappears at sunset in a few years, but gas plants can't wake up quickly from a nap, that demand comes up, and the utility industry calls it an "acceleration" problem.
"In order for the natural gas system to start early and replenish the power supply at dusk, batteries will be needed.
Storage is so new that even executives in the energy industry don't know how to think.
For example, the strange story of Dauren Kilish, an executive at AES Energy Storage in Northern Virginia. Mr.
Kilish's company started building a 40-
Megawatt batteries in Texas include several truck trailers.
About 4,000 of window Air will consume electricity.
In hot weather, air conditioning or absorbing about half the output of small power plants running on natural gas. Mr.
Kilish called the grid operator to register the battery as an asset on the electric network, as the battery is a charge or discharge designed according to the operator's command.
The grid tracks each generator as a resource, but also the business, which can absorb additional energy when the system has a surplus.
So which category should be registered? asked Mr. Kilish.
The system operator says that as a 40-
As a source of supply for 40 MW
Load source for megawatts.
The system operator told the company to list the battery as 80-
Megawatt resources
AES also operates a large battery bank in the center of a wind farm in West Virginia.
But it did not meet the expectations of consumers;
That is to say, store the energy of the wind mainly blowing at night to meet the greater demand during the day when market prices rise.
On the contrary, in the days when the wind changes, when the gust passes, it absorbs extra energy, and when the wind machine suddenly calms down, it pushes the energy back into the grid, to eliminate changes in farm output.
From night to day, the amount of meaningful storage is too small.
According to AES, the value of storage is to increase the flexibility of the system.
However, the recent method of storing a lot of energy for the grid is cold or hot, such as ice or molten salt.
Hundreds of buildings now use their air.
The air conditioning system takes advantage of the low outdoor temperature to freeze the water into ice in the middle of the night to help with the work.
During the day, they melted the ice to cool the air.
In the Arizona desert, a new solar power plant uses the heat of the sun to heat sodium into a hot liquid.
When the sun goes down, sodium is piped into the steam generator, giving out heat to boil water, and water is used to rotate the turbine and generate electricity.
Builders say the cost of using batteries is many times higher.
A company in Houston called TAS Energy stores Energy in the cold.
It cools in the evening, and in the hot summer of Texas, it uses cold water in equipment such as radiators to cool the air sent to the factory that burns natural gas.
When the incoming air is cooler, it will be more dense, so more air will enter the combustion chamber and the power output will be higher.
The effect is to use night energy to increase capacity on a hot afternoon.
Almost all of these technologies lose energy on the road;
That's their turn.
The ratio of the input energy to the extracted energy, the trip efficiency is far less than 100%.
But Darrell Hayslip, president of the Energy Storage Association, said energy efficiency was not the key: dollar efficiency was the key.
"You can't really measure the circle --Travel efficiency;
This is a function of economics, "he said.
"If the charge is $2,
The electricity charge for the discharge is $20, then the bigger price-Travel efficiency. ”Mr.
Hayslip's trading group was established for 20 years, but recently changed its name from "power storage" to "energy storage" to better explain the various forms of energy storage.