It's been two years since Tesla hit the switch on the world's largest battery in South Australia — you know, the one Elon Musk made a bet to build in 100 days or he'd pay for it. Now the company's unveiled another colossal project.

Following the success of the Powerpack system, the tech giant has unveiled the dramatically named Megapack, a giant new battery product designed "to match global demand for massive battery storage projects."

Tesla completed installing the world's biggest lithium ion battery, a Powerpack system with 100 megawatts of capacity, in South Australia in November 2017. Connected to Neoen's Hornsdale Wind Farm near Jamestown, three hours’ drive from Adelaide, the Powerpack system was meant to alleviate some of the state's severe energy issues.

Since then, according to a report by engineering consultants Aurecon, the battery has saved almost an estimated $40 million, while helping to stabilise the energy grid in the region.

So, how does Megapack compare?

Basically, it's bigger. Mega surprising, we know. It's a utility-scale, 250-megawatt battery that, like the Powerpack, stores excess energy generated by renewables like wind power.

Installation and connection to existing energy grids, according to Tesla, should be pretty simple. Each Megapack will be delivered assembled — battery modules, thermal management system, AC interface — with storage of up to 3 megawatt hours, and 1.5 megawatts of inverter capacity. Plus, you can DC-connect the Megapack directly to solar energy sources.

And Tesla reckons it can build 'em fast — the company said that on three acres, it can construct a 250-megawatt, 1 Gigawatt hour power plant in less than three months. That's about the same time frame Musk bet he could build the Powerpack in, and well, they did it.

Each Megapack connects to Powerhub renewable energy monitoring software, and can also be integrated with Tesla's machine-learning platform, Autobidder, which allows for automated trading in electricity markets.

But the big difference is the scale. Megapack is meant for bigger installations, with Tesla claiming each system has a 60 percent increase in energy density. The company's blog post cites the Moss Landing project in California, which has seen the Pacific Gas and Electric Company requesting approval of four cost-effective energy storage projects totaling around 567 megawatts for locations around the state. Tesla is included in the proposal as responsible for one of these projects, a 182.5 megawatt lithium ion battery.

Tesla says the Megapack will act as a sustainable alternative to natural gas power plants, often included in those described as 'peaker' plants.

"Peaker power plants fire up whenever the local utility grid can’t provide enough power to meet peak demand," the post reads. "They cost millions of dollars per day to operate and are some of the least efficient and dirtiest plants on the grid. Instead, a Megapack installation can use stored excess solar or wind energy to support the grid’s peak loads."

The Powerpack, in conjunction with renewables, has already proven its worth propping up fossil fuel plants experiencing outages — there was that baller time Tesla's system bailed out a coal power station nearly 620 miles (1,000 kilometres) away.

With more grunt and storage capacity, the Megapack could potentially make even bigger headlines than that.

UPDATE: July 31, 2019, 6 p.m. BST Updated details about the Moss Landing project.