Tesla has finally unveiled its long promised “megapack” battery, saying it would be a 1.5MW/3MWh unit designed to target the booming utility-scale energy storage market – and marketed as a sustainable alternative to gas “peaking” power plants.

The US electric vehicle and battery manufacturer said on Tuesday that the new lithium-ion product, inspired by the great success of South Australia’s Hornsdale Power Reserve, would allow the installation of gigawatt-scale “power plants” four times faster than a fossil fuel plant.

Tesla chair Robyn Denholm, an Australia, made a rare public appearance on Tuesday, at the Clean Energy Summit, and said the new “megapack” would allow the company to take grid scale storage to a “massive scale”, and would take higher cost and emissions intensive plants – such as gas peakers – off line.

As RenewEconomy readers will know, the 100MW/129MWh Tesla big battery in Hornsdale – still the largest of its kind in the world, but not for long – was built using the company’s commercial-scale Powerpack batteries in a period of just 4.5 months, and at a cost of $91 million.

The Neoen-owned facility – situated next to the Hornsdale Wind Farm – has been a huge success, both as a source of revenue, and for its critical role in maintaining grid security, and preventing blackouts, as highlighted by its response to the dramatic inter-connector failure in August.

Two years later, far from being the “Kardashian” of the energy world that Matt Canavan predicted (and whatever that might mean!), it has set the standard for what the future grid might look like. (Denholm noted it had slashed FCAS costs by 57 per cent and saved the state government $40 million in grid security costs).

“To match global demand for massive battery storage projects like Hornsdale, Tesla designed and engineered a new battery product specifically for utility-scale projects,” the company said.

Tesla says that the new Megapack means an emissions-free 250MW/1 GWh power plant can be delivered in less than three months on a three-acre footprint.

The modular big batteries come from the factory fully-assembled, with up to 3MWh of storage and 1.5MW of inverter capacity.

They build on Powerpack’s engineering with an AC interface and 60 per cent increase in energy density to achieve significant cost and time savings compared to other battery systems and traditional fossil fuel power plants, the company says.

The technology is significantly more compact, too, requiring 40 per cent less space; and less complex, with 10x fewer parts than current systems on the market – allowing it to be installed 10x faster than current systems.

The company says these changes, combined with huge demand for large-scale storage solutions on rapidly changing grids, are expected to grow the amount of Tesla battery capacity installed around the world “exponentially.”

“In the past year alone, we have installed more than 1 GWh of global storage capacity with our current storage products, Powerwall and Powerpack, bringing our total global footprint to more than 2 GWh of cumulative storage,” the Tesla said in a statement.

“With Megapack, this number will continue to accelerate exponentially in the coming years.”