Can solar and batteries take this WA gas hub to 100% renewables?

Western Australia utility Horizon Power is preparing to try powering the Pilbara gas hub of Onslow on “renewables only” during daylight hours, using a combination of customer solar systems, a solar farm and large-scale battery storage.

The trial, which will kick off next week, was announced by Horizon on its Facebook page as a “second attempt” at the milestone achievement of making Onslow – already powered by up to 90% renewables during the day – Australia’s largest town to run on solar and batteries.

The W.A. regional utility said testing would occur on several occasions during daylight hours between the dates of May 19 and May 24, when a team would turn off the gas generators and switch to solar and storage only.

“This work is very complex and while we have planned for no impact to our customers, our engineers and technicians will be onsite to quickly respond if any issues should arise,” the FB post said.

“This will be our second attempt at achieving this milestone, as we implement our findings from the testing we completed back in September 2020.

“If testing is successful, Onslow will become the largest town in Australia to be powered 100% by solar and battery, with no gas fired generators running at the power plant during these times.”

Horizon Power has been working for years on its Renewable Energy Pilot in Onslow, which combines an 8MW gas-fired power plant with distributed and utility-scale solar and battery storage.

Horizon built the gas plant in Onslow – the launching base for the massive Wheatstone LNG project owned by Chevron – and commissioned it in 2018, and then in 2019 delivered the solar farm and battery, with some funding help from Chevron.

At the same time, Onslow residents were incentivised to install solar and battery at their homes as part of the project, which ultimately aims to test the management of renewable energy in an isolated regional community.

When One Step last checked in on the project, in November 2019, Horizon had been using the microgrid control technology to reduce power fluctuations, increase power quality and coordinate power generation from gas plant with the solar farm and battery. At that stage, the project was managing to deliver up to 90 per cent renewables.

Horizon has been at the forefront of remote renewable microgrid development in Australia, largely out of necessity considering the vast and sparse grid it oversees.

As its website notes, Horizon services the biggest area with the least amount of customers in the world – a 2.3 million square kilometre expanse that takes in the Pilbara, Kimberley, Gascoyne, Mid West and the southern region, inlcuding the Southern Goldfields, Esperance, Hopetoun and Norseman.

Just last week, the utility announced it had broken ground on what will become Australia’s first community microgrid to incorporate renewable hydrogen, a $9.3 million project in the town of Denham that aims to demonstrate a sustainable alternative to diesel to power remote towns.