GE sees storage at centre of the grid

GE expects storage to take a more central role in the grid as the penetration of renewables increases. Pic: John Hryniuk Photography for GE.

GE expects storage to take a more central role in the grid as the penetration of renewables increases. Pic: John Hryniuk Photography for GE.

By Jason Deign

Industrial behemoth GE sees energy storage as occupying an increasingly central role in grid stabilisation, Energy Storage Report has learned.

More and more, said Mirko Molinari, general manager of distributed grid systems at GE Grid Solutions, storage and its associated software could act as a central hub for electricity network control, particularly on microgrids.

“In the future, you will see more storage at the centre of microgrids and distributed energy systems, as a functional part of broader grid management controls, just because of the properties it has,” he said.

The view represents a shift in emphasis in the role of energy storage, which until now has mostly been attached to the grid to fulfil specific roles such as frequency control or load shifting.

Putting energy storage at the centre of microgrids or isolated grids would help the electricity networks cope with increasing levels of intermittent renewable generation, Molinari said. 

Traditional grid systems are too slow

Traditional grid systems are “too slow” to react properly to sudden swings in renewable energy generation, he said. But “storage, if properly used, is a very flexible tool.”

This flexibility comes from electricity storage’s ability to instantly absorb excess generation and return it to the system whenever needed, while at the same time providing ancillary services such as voltage and frequency control.

GE’s changing view of the value of energy storage follows what is believed to have been the world’s first demonstration of large-scale battery-based black-start capability, at the Imperial Irrigation District in California, USA, on May 10.

A 30MW, 20MWh GE battery system installed in October 2016 supplied the electricity needed to start a 44MW combined-cycle natural gas turbine (CCGT) at the District’s El Centro Generating Station.

As soon as the CCGT began spinning, the battery system switched to become an energy load consumer, stabilising the power plant.

“A major accomplishment in the energy industry”

“This is a major accomplishment in the energy industry,” said Vicken Kasarjian, Imperial Irrigation District’s energy department manager, in a press release.

“The battery energy storage system did not only provide start-up power, but converted it, allowing the generator to achieve synchronization.

“To our knowledge, this is the first time in history that a battery energy storage system black-started a generator in an operational situation.”

Black-start capabilities have long been mooted as a potential revenue stream for energy storage, but until now most of the practical applications have been linked to pumped hydro plants.

Nevertheless, said the European Academies Science Advisory Council in a May 2017 policy report: “Many storage technologies are well suited to the provision of black start services, including … battery technologies.” 

A more profitable role for storage

Furthermore, it said, ancillary services such as black-start capabilities “offer a more profitable role for electricity storage than energy arbitrage, although the need and corresponding size of the market … is limited.”

Molinari said the provision of black-start capacity “does not justify a huge investment in storage” on its own. But the fact that such capabilities have been demonstrated in practice adds to a growing range of battery value streams.

Being able to take advantage of these depends more on the energy storage software than on battery hardware, however.

This likely explains recent corporate appetite for system developers such as Demand Energy and Younicos.

European utilities such as Enel and EDF, which face the challenge of handling increasing renewable penetration levels on the grids they manage, have tended to lead the charge in energy storage start-up acquisitions. 

Energy-related firms moving into the market

But other energy-related firms have also shown an interest in moving into the market. This month, for example, Siemens joined forces with AES to form a battery storage joint venture called Fluence.

GE, which Molinari said boasts systems carrying two out of every four or five electrons on the grid, can claim to have stolen a decade’s lead on the current battery start-up buyout craze.

In 2007, it bought a UK sodium-metal-chloride battery developer called Beta Research and Development. This later morphed into GE’s first attempt at battery market dominance, under the Durathon brand.

Following lacklustre sales, in 2015 GE quietly dropped Durathon and pivoted towards project development based on lithium-ion batteries.

The company’s current vision of batteries having a controlling role in the grid shows GE hasn’t been put off energy storage by its Durathon experience. On the contrary: GE seems to be valuing storage more than ever before.

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