Return of the steam age

Independent Weekly
Friday 27/3/2009 Page: 14

Panax Geothermal can economically deliver substantial clean power from its Penola plant to the nation, recent feasibility studies show The company's managing director, Dr Bertus de Graaf, said the SA-based company would start drilling its first production well in September and expects to have its first 4.5 MW demonstration plant operating within a couple of years. "We will be on the national grid by 2011 and plan to meet the power needs in the South East before we expand to Adelaide," he said.

"By 2015 we expect to have 10 wells and be generating enough zero-emission base-load power at a total cost of $63 per MW hour to supply 50,000 people in SA." The Penola Project is part of the SA-based company's Limestone Coast Geothermal Project, which is located in SA's south-east, near Mt Gambier. The project has a Measured Geothermal Resource of 11,000 petajoules.

One thousand petajoules is sufficient to power a 100MW power station for 30 years. "Keep in mind that 1000 petajoules in theory can produce 100 MWs continuously and 100 MWs is enough to supply 50,000 homes," Dr de Graaf said. Pre-feasibility studies had shown the cost of Panax's geothermal energy compared favourably to $107/ MWh for wind and solar energy, $62 MWh for gas-fired power generation and $55/MWh for black coal.

Dr de Graaf said studies in the past five years in the Otway Basin, in SA's south-east, had indicated the site could produce hundreds of MWs of base-load power for up to 30 years at a competitive cost, with little impact on the environment. This made the company well placed to meet the Government's increasing focus on renewable forms of energy.

"These projected costs are highly competitive with other renewable forms of power generation, such as wind or solar thermal, and are on par with gas-fired power generation but without the carbon dioxide emissions and associated penalties," Dr de Graaf said.

"The feasibility study has shown the Penola Project to have the scope to be of national significance in the quest to reduce carbon emissions through providing competitively priced, zero-emission base-load power." Dr de Graaf said he believed the Penola Project, when opened, would be the first commercial grid-connected geothermal site in Australia.

Geothermal works by drilling down through a hot sedimentary aquifer, where heat is extracted to drive a turbine for power generation. The Penola Project is based on generating power from existing hot water or brine produced from a known sedimentary basin in the Penola Trough. Because the company's focus is on exploring reservoirs containing hot geothermal fluids it has a shorter development time and is less risky than hot fractured rock geothermal projects, Dr de Graaf said.