Fairwater is a new geo-thermal cooled mini-suburb near Blacktown. Credit:Wolter Peeters Since the temperature below that area of Sydney's west barely budges from about 22 degrees all year round, the earth can serve as a heat dump during summer or a source of warmth in winter. The challenge is to make it at least as efficient as standard products on the market. A $1 million drill, more commonly found on a mining site, drills a simple hole before any of the other construction work begins on the homes. Later, a copper loop containing refrigerant is added, with developers Frasers Property promising energy savings of as much as 60 per cent compared with regular airconditioning. "We're hoping it will exceed that total [saving]," Ray , the Fairwater development director, said. "The payback is about five years." The extra engineering required adds about $3000-$5000 to costs to houses ranging from about $650,000 to more than $1 million. Geothermal costs for two-bedroom houses are lower because pipes only go down 60 metres through the mudstone compared with 90 metres for four-bedders.

Fairwater construction manager Adam Chymiak with the rig that drills the geothermal pipelines. Credit:Wolter Peeters Mr said Frasers worked for more than four years with QPS Geothermal, the drillers, and local airconditioner maker Actron Air to hone the process. The developer is now doing "real life testing" to see how systems performed. Early response A straw poll by Fairfax Media earlier this month found experiences ran hot and cold. Fairwater residents have mixed views of the success of geothermal so far. Credit:Peter Hannam

Sid and Nimarta Banga said they were "mostly positively exuberant" since moving into Fairwater before summer's height. Their electricity bill came in at $260 for about eight weeks. "You can't even feel like the airconditioning is working" because it's so quiet, Mr Banga said, adding "it works really quickly". Fairwater development residents Sid and Nimarta Banga in front of their new home. Credit:Wolter Peeters Around the corner, Manvinder and Deepti Verma were also glad their three-month electricity bill came in at $450 for their four-bedroom house. "We were expecting a lot more," Ms Verma said. The geothermal unit "should pay for itself in three or four years," Mr Verma said, adding that "very few people know about this system".

The equipment, though, has not been without glitches, with a portion of the Vermas' street tripping for several days. The fault left them – and their 15 month-old child – without cooling for two "unhappy" nights and a day during the heat peak. Marc Crook, who rents in another street, is not happy, either. His summer's power bill came to $1385 and the system struggled so much to keep his house cool he resorted to spraying water on the coolant pipes to try to cool them. "They really don't cope at all" once the mercury climbs above the low-30s, he said. "We'd be lucky to get it 24 degrees inside" even with the thermostat turned down to 16 degrees. Mr Crook, who works in the boiler industry, said it stood to reason that "the harder and further you have to pump something, the more heat you're going to generate at the pump", reducing efficiency and effectiveness. 'Great achievement'

Adam Chymiak, Fairwater's construction manager, said that while there may be teething troubles at individual sites the overall outcome was "a great achievement". The energy efficiency of the homes, which include fans in most rooms and LED lightning, meant the estate "lessened the demand on the overall grid" especially at peak times, he said. Fairwater is also the first community in NSW to be awarded a 6 Star Green Star Rating for sustainability. Fairwater is planning to monitor and make public the performance of the geothermal systems, Mr said. Graham Morrison, an emeritus professor at the University of NSW said that geothermal could be an attractive option provided it delivered the promised energy savings: "Sixty per cent is quite OK – technically, it's close to the average of competing products." Frasers is examining rolling out geothermal at its Edmondson estate near Liverpool, and says other developers are looking at the technology for their large sites too.

Professor Morrison said geothermal may work better for cooler climates, such as Melbourne, where heating is a bigger part of the annual energy bill. "Generally, the colder the climate is worse for solar [energy] but better for heat pumps," he said. For Nimarta Banga, the benefit of installing geothermal in new homes may be that residents of a whole community start with lower energy use that may otherwise have been the case – whether they are aware of it or not. "For us, it was a blanket package," she said. "No one will pay out of their pocket for [geothermal]." 'Living building' Frasers Property is involved in another pioneering venture, the $115 million Burwood Brickwoods project in Melbourne's east.

The centrepiece of the mixed retail and housing project over 20.5 hectares on a former industrial site is the shopping centre. The developers are seeking the first "Living Building" certificate issued for a retailer by the International Living Future Institute. The US-based group, which has certified about 360 projects worldwide, demands projects achieve at least net-zero energy, waste and water, and avoid a range of harmful "red-listed" materials from lead and cadmium to chemicals that don't break down in the environment. Frasers will aim to generate 105 per cent of the energy used by the site, deploying as much as 3 megawatts of solar panels and batteries to meet its own needs and to export to neighbours or recharge customers' electric cars. Geothermal technology is not being considered as part of the project. A 2000-square-metre farm, the largest of its kind in Australia, will supply vegetables and even poultry from within the retail site. "It's called a challenge for a reason," Amanda Sturgeon, chief executive of the institute, said.

Peri Macdonald, ‎executive general manager for retail at Frasers, said meeting the building's ambitious sustainability goals will boost the retail portion's cost by about $12 million to $60 million. "It's really going to push the envelope," Mr Macdonald said, adding the extra outlay is worthwhile because shoppers would be expected to linger longer – and spend more – in the more sustainable setting. Loading Tenants, such as Woolworths, have indicated a willingness to meet the higher energy and other standards. "We don't expect it will change the tenant mix," Mr Macdonald said.