Expansion works on the world’s biggest operating battery are progressing at a fast pace. With network connection works now finalized, the upgraded Hornsdale Power Reserve, also known as the Tesla Big Battery, is readying to assume the role of a major asset to the National Electricity Market (NEM).
The capacity of the 100MW/129MWh battery is being expanded by 50%, through the addition of 50MW/64.5 MWh of Tesla batteries. Having attracted an $8 million Australian Renewable Energy Agency (ARENA) grant, $15 million in state funding, and $50 million in project financing from the Clean Energy Finance Corporation (CEFC), owner Neoen expects to complete the $71 million battery expansion before mid-year.
After the installation of battery components had been finalized in March, Neoen Australia announced on Twitter earlier this month that network connection works on the project had been completed. The French renewable energy developer said the expanded battery would “provide soon extra reliability to the grid” in the extremely challenging times characterized by “very low demand and increased risks of outages”.
As already seen in Europe and the U.S., the spread of Covid-19 has slowed down electricity demand and depressed wholesale power prices as shutdowns continue to alter energy use patterns. Australia is following suit in terms of lowered demand and measures have been taken to provide the maximum possible protection of essential electricity supplies.
The 100MW/129MWh Tesla big battery, located in Jamestown in South Australia and adjacent to the 315 MW Hornsdale Wind Farm, has already demonstrated its immense value for the grid in a number of ways. It has brought down grid stabilization costs by some $40 million, according to consultants Aurecon, in its first year of operation alone.
At the same time, Hornsdale generated roughly $50 million in revenues in less than two years through arbitrage trading – buying electricity when wholesale prices are low or even negative and selling when prices are high – as well as the provision of contingency and regulation Frequency Control Ancillary Services (FCAS). As extreme weather, interconnector failures, a risk of islanding, the changing nature of electricity load and coal-fired generator outages combined to lift FCAS demand across the NEM, FCAS provided by the Tesla big battery contributed most of a 56% leap in revenue banked by Neoen in the final quarter of last year.
The added value of digital inertia
The 50% expansion of the Hornsdale Power Reserve is now set to make history as the first battery to provide both grid-scale inertia services and FCAS on the NEM, opening up even more opportunities for grid-scale storage in Australia. Having already proved its worth in FCAS provision, Hornsdale will be tasked with supplying fast-frequency response and system inertia – termed synthetic or digital inertia when delivered by battery storage.
The expanded 150 MW Hornsdale Power Reserve will be upgraded with Tesla’s Virtual Machine Mode, which allows the advanced power inverters, or so-called grid-forming inverters, to emulate the existing inertia services being supplied by a fleet of fossil fuel power plants. The system will test and demonstrate the capability of battery control systems to provide digital inertia replacing the mechanical inertia traditionally provided by synchronous generators while reducing the current curtailment of solar PV and wind generation in South Australia.
This Australian-first battery technology will trial responding to supply fluctuations by automatically and rapidly charging and discharging. The Australian Energy Market Operator (AEMO) 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 the expanded Hornsdale Power Reserve could provide up to half of the total needs.
On top of this, Neoen will also work with AEMO to provide an evidence base to support an update of the current Market Ancillary Services Specifications to increase the permissible level of FCAS registration for all providers, enabling large-scale batteries to provide this service to their full extent and unlock additional revenue streams. Finally, the Hornsdale battery extension could also allow for an increased power flow limit to the Heywood interconnector, resulting in an improvement in spot prices when importing energy from Victoria.
As Australia’s largest PV developer, Neoen has a great number of impressive projects in its pipeline and under its belt, including the proposed Goyder South Project featuring 1200 MW of wind, 600 MW of solar and 900 MW of battery storage. Earlier this month, Neoen and its partner Mondo Power filed a planning application for a massive 600 MW battery storage project near Geelong in Victoria.