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Australian state says 90 firms interested in supplying grid-scale batteries

MELBOURNE, April 3 (Reuters) - Dozens of companies from 10 countries are vying with Elon Musk's Tesla Inc to install Australia's largest grid-scale battery to help keep the lights on in the country's most wind-dependent state.

The South Australian state government said on Monday it had received 90 expressions of interest to set up a battery by December with about 100 megawatts of capacity to store wind and solar power.

That would be used to stabilise the grid at peak times, which tend to be when the sun and wind are low.

Grid stability has become a hot-button political issue in Australia since a state-wide blackout in South Australia paralysed industry for up to two weeks last September, and outages during a severe heatwave over the past summer.

If successful, the storage project could deliver a political windfall to South Australia's government, vindicating their investment in renewables, and give Tesla a high-profile platform to demonstrate their product.

Musk was first to say he could supply 100 MW of battery storage for the state at $250 per kilowatt hour, in a social media exchange with the co-founder of Australian software firm Atlassian Corp, Mike Cannon-Brookes.

"Tesla's interest and enthusiasm in this goes beyond just the Australian market. It is proving a concept and providing a solution," said Gero Farrugio, managing director of renewables consultancy Sustainable Energy Research Analytics.

The South Australian government did not name the companies who had expressed interest in the project.

A handful of companies have publicly said they would consider supplying the battery: Zen Energy, privately owned Lyon Group, working with U.S. power company AES Corp, and Carnegie Clean Energy, using batteries from Samsung SDI Co Ltd.

Lyon Group said last week it would go ahead with a A$1 billion battery project this year, with or without funding from the South Australian government, but the configuration would depend on whether it won any state funding. (Reporting by Sonali Paul; Additional reporting by Tom Westbrook in SYDNEY; Editing by Joseph Radford)