Why isn’t Geothermal Power Catching On?
Geothermal consulting company Hot Dry Rocks in conjunction with Google.org released a surface heat flow map of Australia that revealed the country's untapped geothermal energy supplies. According to the geothermal consulting group, if Australia were to use just 2% of its geothermal potential it could generate ten times more electricity than its total coal and gas electricity production today. Given its vast potential in Australia and other areas around the world why isn't geothermal energy given more attention like other renewable energy alternatives?
Wind and solar energy are the most popular renewable energy sectors with geothermal energy lagging behind. Unlike wind and solar where the energy generated depends on the sun shining or the wind blowing, geothermal energy is available all the time. Geothermal can be a baseload source of renewable energy if you can get to it.
Producing geothermal energy is a relatively simple process. You have to drill two wells in the geothermal site. The water is brought up to the surface using one well and then flashed into steam to power a turbine to generate electricity. The water is then re-condensed and re-inserted back to the earth using the second well.
The problem for the geothermal industry is that exploring these potential geothermal sites can cost a lot of money, about 50 million dollars to drill holes about four or five kilometers deep. The technology to drill is also hard to come by. Currently there's only one rig owned by Geodynamics in Australia and its rig is located in the Cooper Basin. Other companies who want to drill for geothermal energy will have to import drills from overseas.
Another setback to geothermal energy being adopted more readily by the industry is the long time it would take to develop compared to other renewable energy sources. Development and construction of geothermal wells can take from four to eight year which could be too long for investors to wait to get their money. There's also the risk that even after all the drilling the energy output is too low than originally estimated.
Australia is blessed by having geothermal energy that is available everywhere in the county. Australia also has some of the highest temperatures in near-surface rocks anywhere in the world. With the carbon pricing law in effect, companies will have to look to renewable energy sources to complement coal and gas.
"This is clean, renewable energy that is realistically accessible today with existing drilling and power conversion technologies," HDR's Managing Director Graeme Beardsmore said.
"Not only that, EGS has the potential to provide base load power; it is one of the most abundant sources of renewable energy available and is more than sufficient to replace current coal and gas power supply."