SA Water will trial new silicon thermal energy storage technology at its Glenelg Wastewater Treatment Plant next year, in an effort to further increase its energy self-sufficiency and contribute to the corporation's goal of achieving zero net electricity costs by 2020.
Glenelg Wastewater Treatment Plant is already 80 per cent energy self-sufficient, burning the natural biogas created through sewage treatment processes to generate electricity through reciprocating gas engines that is then used in the facility.
SA Water Chief Executive Roch Cheroux said integrating storage would overcome limitations arising from biogas needing to be used as it is produced.
“If we can successfully store surplus energy we generate, we can harness it to better coincide with our peak operational patterns and high electricity market prices,” he said.
“This project will complement our existing energy generation capacity so our wastewater sites can become electricity cost neutral, perhaps even selling energy back to the market.
Adelaide-based company 1414 Degrees recently received a $1.6 million grant from the State Government’s Renewable Technology Fund to progress the pilot program.
The technology will store latent heat in molten silicon at 1414 degrees Celsius to form a 10 MWh thermal storage device. This will release approximately 250 kW for six hours as well as heat which is returned to the plant's digesters.
"Should the trial prove successful the technology could be implemented at other SA Water facilities, such as the Bolivar Wastewater Treatment Plant, which already covers 92 per cent of its energy needs from biogas produced on site.
This project is part of a suite of renewable energy generation, storage, optimisation and efficiency initiatives being pursued by SA Water to achieve its goal of having zero net electricity costs by 2020.
"We’ve already been reducing our electricity costs by more than $3 million a year since 2013, so we know that with a concerted push, our goal is ambitious, but within reach," Roch said.
“Sustainably reducing operational expenses like electricity will help us keep water and sewerage services charges as low and stable as possible, and is one way we can contribute to easing cost of living pressures for our customers.”