Integrating a battery energy storage system (BESS) into a Western Australia gas processing facility’s power generation system was an unconventional approach that paid off in reliability, efficiency and greener operation.
In 2017, when engineering and construction company Clough, part of the Webuild Group, began work on stage two of Western Australia’s Waitsia Gas Project, its experts had their doubts that a BESS could be a viable solution for the development’s energy needs.
At the time, a battery energy storage system seemed too expensive compared to the gas-run generators, which provided the spinning reserve required to maintain power system stability at a 250 TJ per day gas processing facility.
But when Clough was engaged on an existing offshore gas processing facility off the coast of Western Australia with BESS inclusion similar to that for Waitsia, its engineers began reassessing its potential.
“We were aware of BESS capabilities, but we were also mindful of the upfront capital cost and larger footprints needed,” said Hamed Sharafizad, Chief Electrical Engineer, Webuild in Australia.
“For the existing offshore asset project, the layout was dense, making equipment access and egress challenging. A key project task was to remove an existing turbine driven generator and install a BESS in its place. This followed by integrating the BESS into the electrical generation system. However, by 2019, when it was finished, we really saw the opportunities in installing a BESS.”
So when Hamed Sharafizad and his team began working on Waitsia stage two, rather than only using the BESS as a spinning reserve, they explored a multitude of ways the technology could reduce engineering and capital expense across the project.
Greener, cost-effective and more efficient
Other than spinning reserve, the BESS enabled the team to operate larger pump electric motors without the need for assisted starting usually needed to bring them online reducing effects of electric system transients. It also eliminated the need for a separate load-shedding system – another key design aspect initially being considered if the project relied solely on gas fired power generation.
“Load-shedding systems are fast-acting systems that disconnect non-essential loads to maintain the facility power generation so that essential loads ride through transients caused by either planned or unplanned activities,” Sharafizad said.
“If generation capacity is lost through planned or unplanned activity on site, you want to be able to reduce your load and bring it below the threshold of the remaining capacity of running generators so as to avoid cascading shutdown of remaining operating generators. The BESS, as virtual spinning reserve, allows adequate autonomy to bring on a standby generator that can take on that lost generating capacity.”
This delivered savings from an electrical infrastructure and equipment point of view, as well as on the mechanical equipment side including piping and fuel consumption.
“Once we started to tally those savings up, we realised that we had quite a solution on our hands,” Hamed Sharafizad said.
“It’s a bespoke arrangement where, if we do it right, works as a best practice for not just Waitsia, but for future projects as well.”
According to Sharafizad, deploying a BESS for projects such as Waitsia delivers savings on carbon emissions as well as cost. As net-zero goals have become increasingly important, those environmental benefits are being more demanded by clients.
Webuild estimates Waitsia’s BESS installation saves approximately 10,000 t of carbon dioxide emissions per year.
And batteries are becoming increasingly efficient, Sharafizad said. Even though batteries use resources that must be mined and manufactured, that cost is upfront rather than ongoing – and the return on that investment endures for decades.
It also delivers ongoing savings on maintenance, since a comparable internal combustion generator would require service approximately every 40 days, with a major service being needed after every approximately 20,000 hours of operation.
“The investment on a generator is greater because it’s a rotating piece of kit,” Sharafizad said.
“It’s got a lot of auxiliary services, so it’ll cost more due to their complexity; that’s just the nature of it. Battery energy storage, however, is a static installation in nature. For the most part, it remains in a standby state, by storing energy until required to discharge.”
A hybrid approach
Battery energy is most familiar as a source of grid stability for utilities, particularly in conjunction with renewables. Webuild’s BESS solution, however, retains those stability and reliability functions while also integrating a hybrid energy solution into Waitsia’s islanded microgrid that reduces capital expenditure and carbon emissions.
Another advantage lay in the ease of construction and operation. According to Sharafizad, construction companies say that installing the BESS is “one of the easiest jobs they’ve ever done”, requiring little more than connecting a battery box to an inverter that converts the DC current to AC, which then hooks up with the grid via a substation.
“And the results have been fantastic for the Waitsia project,” he said. “We normally work to frequency tolerances of plus or minus 5 per cent. The frequency delta that we have been getting is significantly less than 1 per cent.”
Being able to demonstrate results such as these is a big part of why Sharafizad believes Webuild’s success with the hybrid solution delivered to Waitsia will be a model for its future work.
“For any other project we engage in the future that requires stable power – an islanded microgrid with its own power generation – we can present these results, and that will speak volumes,” he said.
“Projects like Waitsia show how gas infrastructure, flexible generation systems and storage technologies can operate together to support grid reliability while enabling increasing renewable penetration.”
To find out more about Webuild’s work on the Waitsia Gas Project, visit the website.
