Global renewable energy company Neoen has secured approval from the Australian Energy Market Operator (AEMO) to deliver innovative inertia services to the National Electricity Market (NEM) at its Hornsdale Power Reserve big battery in South Australia, writes Greg King-Evans.

The 150MW/193.5MWh facility is the first big battery in the world to deliver grid-scale inertia services and will deliver it through Tesla’s Virtual Machine Mode technology.

The development comes after two years of intensive trials and collaboration between Neoen, Tesla, AEMO, electricity transmission specialist ElectraNet, the Australian Renewable Energy Agency (ARENA), the Clean Energy Finance Corporation, and the South Australian Government.

System inertia – or grid inertia – is a form of energy storage that caters for imbalances between supply and demand on electricity grids across very short periods of time, usually seconds or fractions of seconds.

Electricity-producing generators comprise spinning parts which rotate at the right frequency to balance supply and demand, spinning faster or slower as needed. The kinetic energy stored in these spinning parts is system inertia.

A minimum level of inertia, in conjunction with frequency control services, is needed during normal operation of the electricity network and after major disturbances.

Inertia has traditionally been provided by gas or coal-fired generators, but the closure of thermal power plants, plus Australia’s fast-growing renewable energy sector, is causing inertia shortfalls in the grid.

However, big batteries can help overcome this serious network issue. Through the use of system inertia, Hornsdale Power Reserve (pictured above) will automatically provide stability to the South Australian grid through an estimated 2000 megawatts of inertia, equivalent to 15 per cent of the predicted shortfall in the state’s network, which serves more than 1.7 million people and 150,000 businesses.

“We are delighted to successfully deploy inertia at Hornsdale Power Reserve,” says Neoen Australia managing director Louis de Sambucy.

“I’d like to acknowledge the dedication of our team and our long-term partners at Tesla, as well as our trusted counterparts at AEMO and ElectraNet.”

The South Australian Government contributed $15 million to the project through its Grid Scale Storage Fund, while ARENA contributed $8 million as part of its Advancing Renewables Program.

“Neoen’s Hornsdale Power Reserve is a pioneering project that aims to demonstrate the full technical capabilities of what batteries can achieve,” says ARENA CEO Darren Miller.

“Improving the economics of energy storage is going to be key in our transition to high shares of renewable electricity. We look forward to more grid-scale batteries becoming equipped with advanced inverter capabilities.”

The grid-scale inertia services development at Hornsdale Power Reserve continues the innovative progression at the site since the “Tesla big battery” was unveiled in 2017.

“The Hornsdale Power Reserve was revolutionary when we commissioned it back in 2017 and it continues its pioneering role today,” says South Australian Minister for Energy and Mining Tom Koutsantonis.

“It is leading the innovation of inverter-based technologies, paving the way for large-scale storage projects. Expanding the capabilities of the Hornsdale Power Reserve by activating Virtual Machine Mode, a world-first, demonstrates South Australia’s commitment to global leadership in the adoption and integration of renewable energy to improve grid stability and energy reliability.”