The first system in Australia to combine cogeneration with a geothermal heat pump has been turned on at Fremantle Aquatic Centre in WA.

According to Travis McNeill, general manager at Evo Energy Technologies, who designed the system in collaboration with Wood & Grieve Engineers, the system was sized to get the maximum return on investment and to reduce carbon emissions.

Because of the rising cost of gas, the 75 kilowatt cogeneration system only runs during peak electricity times – between 8am-10pm Monday-Friday – as electricity in off-peak times is far more competitive.

When the cogen system isn’t in operation, the geothermal heat pump can provide the means to keep two outdoor pools at the right temperature, with back-up gas boiler heating that can operate in times of need, such as in winter when heating loads are high or when the other systems are out of commission.

The cogen system, which works in conjunction with a 30kW solar PV array, can provide up to 30-40 per cent of the centre’s electricity needs – including the heat pump, water pump, filtration, administration areas and airconditioning – though the percentage is a little less during winter.

Heat not used can be rejected to the atmosphere, and when additional heat is needed the high efficiency geothermal system kicks in, which uses warm water at around 26°C from the Leederville Aquifer, with the back-up gas boiler coming in a a third lower set point.

The system is expected to result in a CO2 reduction of 205 tonnes.

The project won the 2014 SPLASH (Swimming Pool & Spa Association Australia) award for most environmentally friendly project.