Milestone for Hunter Power Project

Testing and commissioning of the Hunter Power Project (HPP) – Snowy Hydro’s fourth fast-start, on demand gas power station – has begun.

This first phase of commissioning involves pressure testing the HPP’s approximately 23km network of pipe infrastructure that will deliver gas, diesel and water to the station’s generators.

Snowy Hydro said the HPP will be powered by two of the most gas-efficient turbines available and will be capable of delivering 660MW of electricity to the grid. This significant amount of power will make a meaningful difference to supply reliability, helping the network cope during hot weather and outages of transmission lines and other power stations.

As more wind and solar enters the electricity grid, Snowy Hydro said the HPP will play a critical role by providing back-up power to homes and businesses. This means that while HPP is only expected to run around five per cent of the time, it will enable around 2GW of renewable energy to be added to the grid, which is the equivalent of displacing around five million tonnes of CO2-e every year.

Phased commissioning

Alongside the pipe pressure tests, HPP’s switching station, which was built by Snowy Hydro as part of the project but handed over to Ausgrid to operate, will be connected to provide the power station with energy from the grid. Testing will then progress to commissioning the first of HPP’s two turbines and generators.

Pending a smooth process, the first turbine and generator is expected to reach full commercial operation by the end of April 2025. Commissioning of the second turbine and generator will follow, with commercial operation of both turbines and generators expected by the end of June 2025.

Depending on commissioning outcomes, Snowy Hydro said that there is a possibility of either turbine being available to provide some power to the grid sooner. These target dates are dependent on the commissioning program not being impacted by weather or other factors.Snowy Hydro said HPP has experienced extended periods of extreme weather and other factors that have stopped work on the project, impacting its timeline. HPP’s cost has been impacted in order to minimise the delay in its completion, so HPP can produce power for the network as soon as possible.

The utility said that prioritising power availability means the final cost of HPP is expected to be around $1.3 billion, dependent on a smooth transition to commercial operation without delays from weather or other factors.

Despite the change in cost, Snowy Hydro said the strength of HPP’s economic benefit has increased. HPP’s net present value (NPV), has increased to $914 million from $531 million at the March 2021 final investment decision.

According to Snowy Hydro, this increase in HPP’s economic value has been largely driven by:

More wind and solar generation in the grid increasing the need for HPP to provide on-demand, back-up energy to boost electricity reliability

A substantial increase in HPP’s gas storage capacity to 70TJ from 43TJ

HPP’s contribution to managing transmission risk between Sydney and the Snowy Hydroelectric Scheme in the Snowy Mountains, by providing an alternative electricity source for Australia’s largest economy in the event of transmission outages

Local benefits

Snowy Hydro also said that the project is delivering substantial jobs and investment benefits to the Hunter region:

To promote interest in STEM career paths and education, HPP’s team has engaged with local students through career expos and presentations, including through partnerships with the Clontarf Foundation in Kurri Kurri, Youth Express and Training Services NSW.