Delivering sustainable water infrastructure to regional NSW communities

ABSTRACT Water utilities with a population base of greater than 50,000 people can have several economically viable options for ensuring their services provide climate resilience and carbon neutrality through optimisation of their two largest operational expenses (OPEX): power for STP aeration and power for water supply pumping. Energy optimisation can be approached from a number of perspectives, including design, equipment selection, instrumentation and control, energy recovery from the sewage, pumping off-peak, reuse of sewage and water treatment residuals, etc. Smaller water utilities with less than 50,000 people have less latitude for applying these approaches due the lack of economic viability for smaller facilities, lack of staff or other. Smaller water utilities must still strive towards reducing their carbon footprints but maintain affordability to rate payers. Public Works Advisory (PWA) provides technical, advisory and design services to Government Agency clients, including Local Government Areas or LGAs. The PWA partnership with LGAs assists at the local level to deliver on the commitments of NSW and Australia to reducing greenhouse gas (GHG) emissions by 2030. Directly reducing the take and use of grid power supplied by coal fired power stations can have favourable outcomes, both for reducing GHGs and OPEX. The use of solar photovoltaic (PV) systems in Australia is particularly attractive due to the continent having the highest direct normal irradiation or DNI. Current literature gives few examples of real operating data from PV systems in duty on water infrastructure, particularly for smaller installations. PWA target the highest OPEX areas for management of water and sewage and demonstrate with actual operating data from three full-scale case studies. PV panels can be economically employed by smaller water utilities for acceptable Internal Rate of Returns (IRRs), with or without batteries, to help reduce their overall carbon footprints.