When contacted by email, Tesla's media operation declined to answer a list of questions or make any on-the-record statements. But the company did confirm some information about the battery project.
While everyone is calling it a big battery, the 100 MW Tesla storage system — which can provide 129 megawatt-hours of electricity, enough electricity to temporarily power 30,000 homes — actually isn't a single unit.
Instead, it's composed of hundreds of connected, modular Tesla Powerpacks, built at Tesla's factory in Sparks, Nevada, which stand 7 feet (2.1 meters) tall and weigh 3,575 pounds (1,622 kilograms) each. The Powerpacks contain smaller battery pods, based upon the same technology used in Tesla's Model S electric car, as well as a thermal control system and hundreds of sensors that monitor performance, according to Tesla's website. There's also an integrated inverter, to convert the direct current stored in the batteries to the alternating current that goes into the utility system. Each Powerpack can supply 210 kilowatt hours of electricity.
Tesla's Powerpack system is designed to be flexible and scalable, so that the same units can be used to provide power for a few small businesses or, in larger configurations, serve as a backup system for a public utility, according to the website.
As for the newly installed Tesla system in South Australia, the most important innovation is the sheer scale of the project, according to Tony Wood, a former Clinton Administration energy official who now is director of the energy program at the Grattan Institute, an Australian public policy think-tank.
"We will learn a lot over the coming Australian summer as to what role battery technology can play in the accelerating transition from thermal power plants to wind and solar," Wood writes in an email.
The long-term practical potential for battery storage — whether it can help drive a transition to renewable energy, or whether it mostly will be useful for blackout prevention — still remains to be explored. "I don't think anyone really knows as yet," Wood says who notes that battery storage currently remains more expensive than pumped hydro, which uses reservoirs of water as a storage medium. "Economics of scale and other cost-reducing elements are still unclear. That is one reason why this project and others like it are so important and exciting."
Jason Burwen, policy and advocacy director of the Energy Storage Association, says:
"Tesla's project demonstrates three key things. First, battery storage can be deployed on the grid at large scales in very short timeframes that no other resource can match — and this 'just-in-time' capacity provides enormous flexibility in grid planning. While Tesla did this in record time in Australia, it comes on the heels of similar battery projects in California that took only four to six months from contract approval to in service — so this isn't just a one-off. Second, battery storage is here and ready for grid service today. This is not some 'technology of the future,' but rather a current grid solution whose costs are declining rapidly and whose performance is increasing steadily. Third, battery storage is something that everyone gets excited by, regardless of political affiliation. There are few things that unite folks in energy, but it seems clear to me that storage does."