Back in March, Tesla boss Elon Musk promised to provide South Australia with a 100MW battery to help the state make the switch to more affordable, renewable energy. At the time, he promised to get the project done in under 100 days or give it to them for free - more than living up to his promise, Tesla finished the battery installation in only 63 days.
After officially being switched on in December, the battery has gone on to save South Australia millions of dollars. It's accomplished this by easing some of the burden associated with high FCAS costs.
For the unaware, FCAS (frequency control and ancillary services) charges are costs the Australian Energy Market Operator must pay when they ask energy companies to contribute some of their network services to the government in the case of scheduled maintenance or energy system faults.
These costs are typically nothing short of astronomical, RenewEconomy says. At times, South Australia's big gas providers "sometimes [charge] up to $7 million a day for a service that normally comes at one-tenth of the price," typically adding up to about $11,500 to $14,000/MW.
The most recent FCAS request was for 35MW of energy - after an initial, perhaps inevitable price spike, Tesla's 100MW battery bid into the market to help reduce costs to around $270/MW - a tremendous discount for the Energy Market Operator. According to RenewEconomy, this move could have saved South Australia several million dollars in FCAS charges in a single day.