1 July 2014 — A domestic-scale geothermal heating and cooling system developed by Brisbane company QPS Geothermal has attracted interest from developers Sekisui House and Australand, as well as energy giant AGL, within the first six months of being on the market. With its attractive payback period of 2-3 years for residential and as little as 12 months for commercial, the developer of the system predicts the technology will be used in all new homes in five years.
The GeoAir system has been installed at Sekisui House’s display home at Ecco Ripley in Brisbane for the past 12 months, and is now being offered to buyers at The Hermitage subdevelopment in Sydney, where the ground infrastructure component is being pre-installed.
Australand is trialling the technology at Botanica, also in Sydney, and AGL has partnered with QPS to deliver the first commercial GeoAir installation at Maroondah Sports Club in Melbourne.
The system comprises a copper ground loop up to 80 metres deep installed in a hole 125mm wide. The loop is filled with refrigerant and cemented in place by a specialist geothermal grout, and the system incorporates a ground-level heat pump designed and patented by QPS and manufactured under licence in Australia.
The package as a whole reduces the upfront cost of a geothermal installation compared with a traditional multi-well approach, and delivers higher cooling and heating efficiency than the water-filled systems used in 40 per cent of European and USA homes.
By using the stable temperature of the ground as the heat exchange medium, testing has shown GeoAir delivers between a 60 per and 80 per cent saving on cooling and heating costs compared to a conventional airconditioning system. This gives the technology a payback period of between two to three years in the residential setting, and as little as 12 months for commercial settings such as aged care where the airconditioning system is in use 24 hours a day.
Vertical integration and breakthrough technology
QPS director Paul Costello told The Fifth Estate the company’s vertically integrated approach to delivering GeoAir was also a key part of making the technology an affordable proposition.
As a ground engineering firm with 17 years experience, the installation part of geothermal is something GPS was already equipped for in terms of inhouse geotechnical engineering, drilling crews and drill rigs, in addition to in-house mechanical engineering and design expertise.
In 2010, the firm began investigating the development of a residential-scale geothermal system, inspired by the systems in use in Europe and the US, and given further impetus by an Australian firm’s request for assistance with the ground engineering side of a geothermal project.
“We were already operating in the green space, as we had been doing a lot of ground engineering works for wind farms,” Mr Costello said. “And because a lot of our drilling equipment comes from overseas, we had been introduced to the concept of geothermal energy systems and how they work.”
The research and development of the system, including the loop and the patented heat pump, was funded by the company’s ground engineering, ground anchors and drilling activities.
Extensive testing, including installation at their own head office premises at Eight Mile Plains in Brisbane and a number of other sites, enabled the company to refine the system and develop accurate baseline data for its performance and cost-effectiveness.
And it’s quiet
These tests also showed the system has near-silent operation of just 51 decibels, and in addition to producing heating and cooling energy for the airconditioning system, can be used for domestic hot water and pool heating.
The refrigerant passing through the ground loop either heats or cools to the constant earth temperature of around 20 degrees, which means the degree of added energy required to adjust the temperature appropriately to the specific heat or cool temperature set by the air conditioning thermostat is minimal.
Cooling by 1-2 degrees instead of 18-20 degrees – that’s the big benefit
The greater the degree of climatic variance, the greater the benefits, for example, to cool air on a 40 degree day by regular means requires a standard system to achieve up to 18 or 19 degrees of cooling; when the passive energy of the earth is used, the difference may only be one or two degrees if the thermostat is set for the recommended 21 or 22 degrees.
“The big breakthrough with our system was we halved the depth required for the loop,” Mr Costello said.
“Some of the difficult part in terms of geothermal systems for other companies was the drilling and installation of the loop – that process used to add a significant premium. But drilling and ground engineering is our core expertise, and we have got that part down to a very manageable cost. That combination of existing skill and the breakthrough in depth and performance of the loop has achieved the [very short] payback period and brought the system in reach of the average person.”
Bringing GeoAir to market
QPS had been working closely with land developers, including Australand and Sekisui House, for the past 12 months to achieve the current installations of the system in new subdevelopments and lay the groundwork for full rollout to home buyers.
While the technology can be retrofitted, due to the challenges of using a drill rig on a constrained site footprint, the logistics are far simpler if the loop is installed as part of early works.
“What we are looking at with the big developers is pre-provisioning the site, with the prebuilt loop and patented heat pump system installed,” Mr Costello said.
Currently QPS has between 90 and 100 staff, and Mr Costello said this number was soon to increase, with the company in active recruiting mode.
“In our geotechnical division we have been moving some staff into New South Wales, Victoria and South Australia as the demand for the GeoAir system is growing rapidly,” he said.
The partnership with AGL, which is the agent for the system in New South Wales and Victoria, has also leveraged installations in South Australia and Queensland for a number of private homes.
Mr Costello said AGL had been looking for a geothermal option to complement the company’s growing retail offering of airconditioning products through AGL shop fronts.
QPS maintains all ownership of the patents and design, and completes all installations for AGL clients using direct QPS labour and fully-owned drill rigs, maintaining the logistical and cost efficiencies of the fully vertically integrated delivery model.
QPS is currently engaged in further research with the University of Queensland and other research bodies to develop a system with even shallower loop depths, which would reduce the price of the system even further.
Mr Costello said another advantage of the system was that by reducing the overall home energy load, it improved the probability of domestic solar systems being able to supply all or most of the home energy requirements, and without solar, reduces peak load demand on the energy grid from heating and cooling.
“If I look forward in a crystal ball, in about five years or so, there will be some form of geothermal and solar in every new house,” Mr Costello said.