Tesla 
 
 Need extra storage? Tesla has announced it will build the biggest-ever lithium ion battery in South Australia. 
 
 The 100 megawatt battery will act like an electricity back-up – it will store excess energy generated by a wind farm when electricity demands are low, then feed it back into the grid during peak hour. 
 
 South Australia has adopted renewable technologies faster than any other state in Australia, but repeated blackouts since September have sparked uncertainties about their reliability. 
 
 Advertisement 
 
 In March, Tesla founder Elon Musk offered to fix the problem with a large-scale version of a Tesla car battery. On Twitter, he said he would get the system up and running within 100 days, or else do it for free. 
 
 Today, South Australian Premier Jay Weatherill announced that a deal had been struck. Tesla’s megabattery will be paired with the Hornsdale Wind Farm, which is being built near Jamestown in the state’s mid-north region. The launch date is expected to be in December this year. 
 
 Tesla 
 
 The battery will in fact be made up of thousands of Tesla car lithium ion batteries packed into hundreds of refrigerator-sized units spread across a field. Combined, they will be able to power 30,000 homes. 
 
 “You can essentially charge up the battery packs when you have excess power when the cost of production is very low… and then discharge it when the cost of power production is high, and this effectively lowers the average cost to the end customer,” Musk told reporters in Adelaide, South Australia today. “It’s a fundamental efficiency improvement for the grid.” 
 
 Scaling up 
 
 Tesla recently built a smaller battery farm in California after a leak at a natural gas facility led to fears of future energy shortages. The 20 megawatt hour system is made up of 396 refrigerator-sized units and was installed in less than 90 days. 
 
 Scaling up the size will come with technical challenges, but Musk says he is “confident in our techniques and the design of the system.” It will cost him $50 million or more if he cannot install it within the 100-day agreement, he says. 
 
 The batteries will require extensive cooling, because like lithium ion phone batteries, they can overheat. They will also lose efficiency over time and need to be replaced. 
 
 If the project can get off the ground, it will be a significant innovation, says Ian Lowe at Griffith University in Queensland, Australia. “Cost-effective storage of electrical energy is the only problem holding us back from getting all of our power from wind and solar.” 
 
 It will be a learning experience for Tesla, South Australia, and the rest of the world, says Ariel Liebman at Monash University in Melbourne, Australia. “It’s the first step on a 1000-step journey.” 
 
 Read more: Beyond batteries: This technology could revolutionise energy 

 SYDNEY (Reuters) - Tesla Inc (TSLA.O) has won an Australian contract to install the world’s biggest grid-scale battery, in what experts say will be a litmus test for the reliability of large-scale renewable energy. 
 
 South Australian Premier Jay Weatherill (R) listens to Tesla Chief Executive Officer Elon Musk speak during an official ceremony in Adelaide, Australia, July 7, 2017 to announce that Tesla will install the world's largest grid-scale battery in the South Australian state. AAP/Ben Macmahon/via REUTERS 
 
 Tesla’s CEO Elon Musk, known for his bold approach to cars, clean energy and space exploration, trumped dozens of competing proposals to build the gigantic lithium-ion battery that will serve as emergency back-up power for South Australia - a state racked by outages. 
 
 But under the agreement, Tesla must deliver the 100-MW battery within 100 days of the contract being signed or it will be free - a commitment Musk made in a Tweet in March. 
 
 “There will be a lot of people that will look at this -‘Did they get it done within 100 days? Did it work?’” Musk told reporters in South Australia’s capital city of Adelaide. 
 
 “We are going to make sure it does.” 
 
 The battery, designed to light up 30,000 homes if there is a blackout, will be built on a wind farm operated by France’s Neoen - parts of which are still under construction. 
 
 Musk said failing to deliver the project in time would cost his company “$50 million or more”, without elaborating. 
 
 It will be the largest lithium-ion battery storage project in the world, overtaking an 80 megawatt-hour facility in California, also built using Tesla batteries. 
 
 Over the last three years, South Australia has decided to shut down its coal-fired power stations and instead rely on wind, solar and gas. In particular it has raced ahead of the rest of the country in turning to wind power, which supplies 40 percent of its energy. 
 
 The move has been applauded by environmentalists but left the state prone to outages as there is no way to store enough energy when the wind doesn’t blow. In September, South Australia’s 1.7 million residents were left without power, some of them for up to two weeks, when the grid overloaded and collapsed. 
 
 The battery is aimed at getting around the problem of inadequate storage. 
 
 “Cost-effective storage of electrical energy is the only problem holding us back from getting all of our power from wind and solar,” said Ian Lowe a professor of science at Australia’s Griffith University. 
 
 “This project is a significant innovation to demonstrate the feasibility of large-scale storage.” 
 
 LITHIUM AMBITIONS 
 
 Dozens of companies from 10 countries, including privately owned Lyon Group, working with U.S. power company AES Corp (AES.N), expressed interest in the project. 
 
 Now the sector is waiting to see if Musk can make good on his promise. 
 
 “Tesla has been telling the world that it can and will finish the project within three months, said a source at a Korean competitor to Tesla, declining to be identified due to the sensitivity of the matter. 
 
 “It seems that confidence helped Tesla win, but typically this kind of project takes six months so we have to wait and see whether or not Tesla can do it,” the source said. 
 
 Tesla Chief Executive Officer Elon Musk speaks during an official ceremony in Adelaide, Australia, July 7, 2017 to announce that Tesla will install the world's largest grid-scale battery in the South Australian state. AAP/Ben Macmahon/via REUTERS 
 
 Lithium-ion batteries have been in widespread use since about 1991, but mostly on a small scale, such as in laptops and cell phones. A typical lithium-ion battery can store 150 watt-hours of electricity in 1 kilogram of battery, representing more than double the capacity of nickel batteries. 
 
 For their proponents who have long been pushing for grander use, the success of Musk’s big South Australian experiment will be key to greater acceptance. 
 
 “For lithium technology to take off on a global scale, they clearly need the storage capacity to make sure renewables can deliver 24 hours a day, seven days a week,” said Adrian Griffin, a geologist who specializes in lithium extraction.
– Elon Musk has an ambitious new project on his plate: building the world's largest lithium-ion battery. The 100 megawatt battery, which will be put together by Tesla and French energy company Neoen, will store renewable energy for the state of South Australia, the Guardian reports. The battery will be linked up with a wind farm near Jamestown and able to power 30,000 homes, per Reuters; it will hoard extra energy created by the wind farm during non-peak times then offer up its stores during emergency situations, New Scientist reports. "This will be the highest power battery system in the world by a factor of 3," Musk tweeted, echoing comments made in Adelaide Friday where he said "the next biggest battery in the world is 30 megawatts," reports the BBC. The New York Times reports that an offer from Tesla's battery division emerged in March after "a string of embarrassing power outages" in South Australia, and the state's government confirms the Tesla CEO is standing by his pledge made that same month that if Tesla can't produce the battery within 100 days of signing a contract, it will be gifted free of charge. The BBC suggests that countdown clock has not yet been set, and will be after the signing of an "electricity grid interconnection agreement"; media reports indicate the battery will be put in place before December. "South Australia is already leading the nation. Today, we lead the world," South Australia Premier Jay Weatherill tweeted Friday, showing a pic of himself and a grinning Musk. (A "Tesla for the masses" comes out Friday.)