“The solution to the world’s shortage of fresh water to provide for the needs of a growing population, and for clean energy cheaper than coal and more reliable than solar, has been under our noses for more than two millenniums.
The answer to our needs lies in the thousands of confined, fresh-water aquifers that account for about 6 per cent of the world’s fresh water.
Leaks in these aquifers are called ”seeps”. Water has been flowing from these seeps since the last ice age. Some of these aquifers are huge – bigger than the Great Artesian Basin.
One aquifer supplying a multiplicity of seeps extends from the Gulf of Mexico to New York.
The water in many seeps actually appears as fresh water on the surface of the ocean. This has been used by sailors as a source of fresh water since the time of the Phoenicians and must have been used by the Polynesians navigating the vast distances between islands in the Pacific.
The ancient Greeks considered seeps in the Mediterranean as connections to the gods. The English translation of Bahrain is ”two oceans”.
The ancients knew the location of the seeps because they were crucial to trade. Understanding the physics can allow modern man to capture the energy as well as exploit the water for irrigation.
The deeper the seep the more potential energy it stores, as shown by the power of the flow at the surface.
To imagine the principle, think of a lava-lamp where a bubble rises to the top of the lamp because it is lighter than the surrounding fluid. Fresh water is lighter than salt water.
The ancient mariners used this energy to divert water from the ocean floor directly into the boat. The energy captured was sufficient to lift the water into the boat. Engineers have devised a method of capturing enough energy to run a hydroelectric power generator located above the water line of the ocean to produce four megawatts of electricity – enough to power a small town.
Hydroelectric power involves transfer of potential energy in a dam to electricity. This scheme turns this process upside down.
How the scheme works in principle is subject to a patent. It has received the backing of Docklands Science Park, which has obtained initial funding to test the process using new materials.
There are several seeps along the south-east coast of Australia that are being considered for this test, including one near the Wonthaggi desalination plant. The cost of the test – tentatively called Submarine Hydro Energy Systems (SHES) – is expected to be less than $15 million, because most of the parts used in the system can be bought off the shelf.
The system being tested will, if successful, be able to be made bigger. The units would be placed on or offshore, but ideally close to power grids.
Many countries already know where the seeps are located and they appear on marine charts.
In Australia, significant seeps are known to occur off Perth and the Great Barrier Reef. But infrared satellite imaging reveals the general location of seeps right around Australia. In fact, it is hard to find locations that don’t have them.
If the test is successful, it will simply be a question of choosing the least expensive seep locations close to the grid and population centres.
And here’s the really good news: engineers calculate that the wholesale cost of electricity produced by the SHES method will be about 2.5¢ – about a quarter of the cost of thermal coal in Australia and the US, excluding any carbon tax.
SHES electricity can be produced emissions-free and the ”waste” water can be available for irrigation and upgraded to drinkable standard, using some of the electricity to de-ionise the water for minimal expense using a process developed by Docklands Science Park. A de-ionisation demonstration station plant already operates at Werribee.
Sceptics can legitimately say that SHES plants do not exist and therefore the science does not exist, or that there may be unforeseen operating problems. But this is really an argument for building a demonstration plant.
The $15 million cost is nothing compared with the $20 billion already committed to the North-South Pipeline and the Wonthaggi desalination plant. The utter waste involved in building these two gigantic white elephants was pointed out ad nauseam to successive Victorian governments.
If the SHES pilot performs to expectations it will prove to be a globally transformative technology. It will make thermal production of electricity obsolete, provide unlimited supplies of cheap electricity, make it easier for the planet to avoid environmental tipping points now predicted by the World Bank, and provide more food for a population expected to peak at 9 billion.
And the downside? A few red faces if the pilot plant exposes major problems that cannot be overcome.
The biggest risk is that the technology works and is appropriated by competitors who have the muscle and foreign-government backing to ignore the intellectual property rights owned by the Victorian developers.