A senior solar energy researcher from the University of Queensland has questioned the role of grid-scale battery storage as the “missing link” of Australia’s shift to renewables, and suggested that much more research needs to be done if the technology is to be rolled out successfully.
Professor Paul Meredith – who is the head of solar at UQ, and oversees the University’s world-leading research project, the Gatton PV Pilot Plant, which is being conducted in conjunction with First Solar – says that while the technology is available, adding grid-scale battery storage to the NEM will be highly complex, and just one part of the future grid puzzle.
“You have to be very, very careful suggesting that one technology is the panacea,” Meredith said in an interview with RenewEconomy.“It is not a trivial problem.”
Meredith’s comments follow up on last week’s op-ed from energy policy expert and economist Ross Garnaut, who called for the deployment of grid-scale battery storage as an “ready and immediate solution” to the integration of large-scale renewables in Australia.
Garnaut’s article, which was published in the Australian Financial Review, was partly written in response to the South Australian “energy crisis” and the attacks on large-scale renewables uptake that this has provoked.
“An immediate answer is grid-scale batteries, which are being deployed in other developed countries to balance increasing volumes of wind and solar energy,” Garnaut wrote.
“Batteries can respond to the need to add or absorb power in less than a second – much more quickly than gas generators.
“If optimised to maximise value in provision of grid stability services, the battery can store surplus power from excess generation from the midday sun or overnight wind for use in the evening and morning peaks at total costs that are lower than the prices of wholesale hedge contracts, or than exposure to the wholesale market at these times.”
While all this is true of the technology, Meredith argues that “optimising” the batteries is a highly complex business, and needs to be done correctly from the outset, to avoid embedding new inefficiencies into the grid.
At Gatton – a solar research project that has been nearly “five years in the cooking” and which has slashed campus grid electricity use by 40 per cent and delivered a 10 per cent higher average annual energy yield than projected – a 760kWh li-iom battery system by Kokam was chosen to complement the 3.275MW PV array, which is installed over 10 hectares on a former UQ campus airstrip, located at the end of an 11kW SWER (single wire earth return).
Meredith said his team had put a lot of time into choosing the right battery to fit the huge PV array, and had subsequently taken between four and five months to develop an understanding of how to use it properly.
“It’s site by site specific,” he told RE. “You need to know how to optimise the value of the battery and that means when to dispatch the energy, when to discharge, recharge, …the right control system implementation, how to harvest maximum efficiency.
“I’d really like to see … an appreciation of the complexities,” Meredith said. “It’s our job that people understand these things. Certainly we’ve written our own control interface to make sure we use our battery properly.
“More research (into how to correctly deploy grid-scale battery storage) needs to be done very carefully and very fast,” Meredith said. “It will be too late in three year’s time, we’ll have all this battery storage out there not working properly.”