Having built the world's biggest battery in the Australian state of South Australia a year ago to provide energy to the grid in the event of a supply shortage, Tesla is now involved in the state's next energy security plan by helping to create what's known as a “virtual power plant.” And it's all emissions free.

Working with its partners, the South Australian government will install solar panels and battery storage systems, in this case Tesla's Powerwall 2.0, at 50,000 homes in the state over the next four years. All of the homes are already connected via the existing energy grid so collected energy can easily flow where it's needed, using a software management system that accesses each home’s battery and then instructs it to release energy to the grid in times of need.

The energy will be generated and stored in the batteries during the day, when demand is low, and then discharged during the night, when demand is high. At peak generation, the virtual power plant is expected to generate 250,000 megawatts, or as much as a small coal power plant.

Each of the homes will feature a 5-kilowatt solar panel system and 13.5-kilowatt-hour battery storage system. Private investment and taypayer funds will be used for the installation but will be repaid over time via the sale of the generated electricity. Individual households in the network are expected to benefit from significantly lower energy bills, with analysts predicting a 30 percent reduction in energy costs on average.

An initial trial involving 1,100 public housing homes has already commenced. This will be expanded to 24,000 public housing homes following the trial and then the deal will be offered to more residents in the state.

Audi in January said it would conduct the trial of a similar virtual power plant in its hometown of Ingolstadt, Germany, but on a much smaller scale.