About 650 meters below the Latrobe valley lies a vast, undervalued source of clean energy to be tapped.
About 650 meters below the Latrobe Valley, the heart of Victoria’s coal country, lies a little-known, naturally warm 65℃ of water in a vast aquifer.
This aquifer is a source of geothermal energy – a renewable source of heat or electricity, which has so far been used to heat an aqueous center in the city of Traalgon. They chose it – over natural gas, coal-fired electricity or even emission-free solar and wind – because geothermal energy is now the cheapest option for heating.
The warm aquifer was first reported in 1962, when government geologist JJ Jenkin noted several “high-temperature water events in East Gippsland”.
We now know that warm water extends from Morwell in the west to Lake Entrance in the east under about 6000 square kilometers of Gippsland, and is equivalent to $30 billion of heat at today’s natural gas price.
But with natural gas flowing through the Bass Strait and vast reserves of brown coal in the Latrobe Valley, there has been little incentive to develop alternative energy sources. With the coal age now over, it is time for us to make better use of this vast, clean source of energy to help cut national emissions and ease the energy transition.
geothermal energy around the world
The temperature of the Earth’s core is equal to the temperature of the surface of the Sun. That huge internal heat is like a hotplate heating the natural groundwater from below. Below the Latrobe Valley, thick layers of coal act like a blanket, making the underlying aquifers warmer than the aquifers in other locations. The result is unusually warm natural water that doesn’t require any fossil fuels to burn – emissions free. At deeper depths we can capture natural steam, and use it to turn turbines for generators.
In many parts of the world, natural hot water already provides sustainable, low-emission heat to a wide range of residential and industrial consumers.
Doing a recent global scan of energy production from hot aquifers, I learned that large parts of suburban Paris are heated by geothermal energy from a hot (56-85℃) aquifer between 1600 and 1800 meters below the city.
In the Netherlands, industrial-scale greenhouses are replacing their natural gas heating systems with geothermal heat from aquifers 1800–2200 m below the surface.
Beijing is one of the world’s leading urban centers using geothermal energy. Wells up to 2600 meters deep produce 70℃ of water for many industrial purposes, from winter heating for hotels and factories to greenhouse farming, in public geothermal bathing pools visited by 50,000 people per day.
On a smaller scale, a city in Hungary circulates natural hot water (64–72 °C from 1450–1700 m depth) through a network of distribution pipes. and Perth, Western Australia, uses natural warm water (750–1,150 m to 40–52 °C) to heat at least 14 leisure and aquatic centres.
Importantly, in almost every case, the water returns to the aquifer only after giving up its heat. In other words, the production of geothermal energy does not consume water, making it renewable and sustainable.
When compared to geothermal systems around the world, this apparent natural warm water beneath the Latrobe Valley, at just 650 m deep, is a truly world-class geothermal energy resource, largely overlooked until now. has gone.
cheap gas alternative
It is much cheaper to drill a 650m bore than a 1500m or deeper bore. This means that the production of geothermal energy in the Latrobe Valley is cheaper than in many places where geothermal energy already provides economic benefits.
In fact, geothermal heating is a much cheaper alternative to natural gas. Since Australia began exporting liquefied natural gas from Queensland in 2015, the wholesale price of natural gas in eastern Australia has nearly tripled and is projected to continue to grow and remain high.
The high price of natural gas affects the economy throughout Australia. The federal government estimates that 40% of the energy Australian households use for heating and cooling, and 23% for water heating. A 2019 report commissioned by the Australian Renewable Energy Agency found that 52% of the energy used by the country’s industrial sector is consumed as heat.
But there are other long-term benefits that geothermal energy resources can deliver to the Latrobe Valley.
Victoria’s heavy reliance on natural gas for heat also presents a major challenge for the state to meet its legislative greenhouse gas emissions reduction target of net zero by 2050.
Under the plan, the remaining coal-fired power plants in the Latrobe Valley are set to close in the coming years and decades, requiring support to re-skill workers.
The production of geothermal energy from hot aquifers could help on both fronts: by avoiding greenhouse-gas emissions and by re-employing skilled workers into new industries.
What will happen next?
I am working closely with a range of stakeholders – including Latrobe City Council, the Latrobe Valley Authority, the Geological Survey of Victoria, local businesses and community groups – to realize the potential of this vast, low-cost source of clean energy .
We strive to better understand and sustainably develop this resource to help Australia meet its emissions reduction targets and reduce the cost of energy.
This includes projects such as mapping, investigating the potential for power generation from deep hot rocks, and identifying and clearing policy and regulatory bottlenecks.
The lessons we learn in the Latrobe Valley will carry over to Victoria and other parts of Australia – such as the Mornington Peninsula, the Otway Coast, and the Great Artesian Basin stretching across NSW, Queensland and South Australia – where warm waters tend to lie deeper. Goes, but still very accessible.
This article originally appeared on Conversation and was reproduced with permission