Sustainability for sea change town

Planning for reduced energy options

Australia's tree change and sea change movement has seen the resident populations of traditional holiday towns swell in recent years. This growth puts a strain on essential services like electricity to keep up with demand. Factor in the environmentally sensitive nature of these locations and the need to come up with sustainable, low carbon emission households and a developer's task can get extremely complex.

Gracetown, in the south-west of Western Australia on Cowaramup Bay near Margaret River, is a small coastal settlement where planning is underway to provide further residential lots. The Western Australian government's land and property development agency, LandCorp, has proposed the development of approximately 140 additional residential lots in the village with project construction commencing in around 2012.

Professional services company GHD was called in by LandCorp to develop sustainable energy options for the lots as well as ways to reduce carbon emissions generated as a result of energy consumption.

GHD had to take several challenges into account including:

“First we considered households and the fact the sites lent themselves to solar solutions,” said GHD Senior Sustainability Consultant Dr Dubey.

“GHD worked up a range of solar photovoltaic energy options that it calculates can reduce average greenhouse gas emissions from household energy use by between 41 and 74%.

“These options are sustainable and, importantly for the householder, make good economic sense too. We estimate each will produce cost savings over a 20-year period as conventional energy costs rise.

“We also looked at encouraging householders to purchase renewable energy through the national GreenPower program for the remainder of their electricity needs. Savings of up to 94% on average greenhouse gas emissions from household energy use may be achieved.”

Building energy ratings, too, were seen as important. GHD estimated achieving a six-star compliant house energy rating (Building Code of Australia) would reduce annual household energy emissions by 6% over a mandatory five-star rating.

New lots require new wastewater services. In keeping with the development's sustainability vision, GHD analysed several renewable energy options for powering a wastewater treatment facility that would cater for new residents.

“Wind turbines came out the winner,” Dr Dubey said. “As a primary power supply they are actually the most cost-effective method of providing power to the facility over a 20-year period, even when compared to conventional supply.”

Currently, the expected annual electricity consumption of the wastewater treatment facility will be offset by wind energy generated at (or close to) the site. Based on the expected annual electricity demand, this is expected to be three 20 kW wind turbines. Annual energy greenhouse gas emissions from the wastewater treatment facility are expected to be zero (saving approximately 190 tCO₂ per annum).

“LandCorp knows that in order for residents to enjoy living in a beautiful coastal town they need to work with the location instead of against it,” Dr Dubey said.