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Strengthening the South Australian electricity grid

The fast ramping capability of the Tesla Powerpacks used at the Hornsdale Power Reserve means that the facility can dispatch large amounts of power quickly and reliably. This means it can support the South Australian electricity grid and make major cost savings by providing frequency control and short-term network security services.

In 2019, HPR reduced costs in the National Electricity Market by $116M through the provision of Contingency and Regulation Frequency Control Ancillary Services (FCAS).

Aurecon Report, 2018 –Technical & Market Impact

Aurecon Report, 2019 –Technical & Market Impact

Frequency Control Ancillary Services (FCAS)

FCAS is a system in the National Electricity Market that helps maintain the power system at the right frequency, namely 50Hz. If the frequency goes outside the Normal Operating Frequency Band (49.85Hz to 50.15Hz), the power system will face significant issues, potentially leading to complete blackouts. For instance, if power generation rises, the frequency will rise. Similarly, if electricity demand increases, frequency decreases. Therefore, demand and supply need to be permanently equal in order to keep the frequency as close to 50Hz as possible. It is AEMO’s responsibility to manage this through the FCAS markets

Dispatching large amounts of renewable power

A portion of the battery is dedicated to trading on the electricity market. This capacity is being used to store power from the grid when demand is low and dispatch it when demand is high, reducing the need for expensive gas ‘peaking plants’ and placing downward pressure on power prices for South Australian consumers.

At 100MW/129MWh (soon to be expanded by a further 50MW/64.5MWh), the Hornsdale Power Reserve is the largest lithium-ion battery in the world. When dispatching at peak output, the battery provides enough electricity to power the equivalent of 45,000 homes.

Project expansion benefits

In addition to continued energy bill savings for consumers, the expansion will also provide an Australian-first large-scale demonstration of the potential for battery storage to provide the stabilising inertia services that are critical to the future integration of renewable energy. This will ensure South Australia can continue to harvest its world class wind and solar resources and achieve its target of being net 100% renewable by 2030. It will also see the State transition to become a net-exporter of cheap and clean energy to the NEM and further drive down electricity prices for all consumers.

Virtual Inertia

As with vehicle suspension on an uneven road, inertia services are essential for stabilising the grid when electricity supply and demand fluctuate. The expanded 150 MW Hornsdale Power Reserve will be upgraded with Tesla’s Virtual Machine Mode, which allows the advanced power inverters to emulate the existing inertia services being supplied by an ageing fleet of fossil fuel power plants. The level of inertia that would be provided by HPR could match half of the total needs of South Australia.

This Australian-first battery technology will trial responding to supply fluctuations by automatically and rapidly charging and discharging. By imitating the behaviour of the existing fossil fuel-based services, the Hornsdale Power Reserve can arrest any grid frequency deviations through a clean and regenerative substitute.

The Australian Energy Market Operator has identified that the South Australian grid requires 6,000 megawatt-seconds (MWs) to maintain a secure operating level of inertia. It is anticipated that Hornsdale Power Reserve as expanded could provide up to 3,000MWs of inertia.