Australia?s Drought and Oceanic Opportunities
While Australia presently endures a drought, their weather history includes previous prolonged periods of drought. In response, authorities built the controversial Wonthaggi desalination plant in Melbourne. While it was expensive to build and is expensive to operate, it can supply Melbourne with up to one third of the requirements for potable water. There are numerous other and perhaps less costly oceanic opportunities for Australia.
Prolonged periods of drought seriously curtail agricultural production in areas of fruit, vegetables and feed for livestock. In the latter regard, a recent discovery that occurred on of the Shetland yielded a surprise about the long-term grazing habits of a herd of sheep. When the tide goes out, the sheep march to the exposed sea floor to graze on a variety of oceanic vegetation and have apparently been doing so for perhaps 5,000 years. The discovery suggests that there may be scope to raise large numbers of the particular breed of sheep overseas, where food could be provided.
Occurring concurrently, an American entrepreneur has developed a sea farm where he cultivates sugar kelp while also raising shell fish. There are apparently some 200 edible varieties of oceanic vegetation. The entrepreneur grows the kelp inverted, using submerged buoys to suspend platforms below the level of waves and from which the sugar kelp would grow from higher to lower depth. In nations such as Japan and South Korea, snacks such as crisps made from kelp are sold commercially and exported into overseas markets. Australia’s extensive coastline should be able to support kelp farms.
Oceanic Vegetation Uses
Sea kelp contains a variety of minerals and nutrients, and when dried and powdered, can be processed into a powdered fertilizer that can in turn sustain the growth and development of cultivated land-based vegetation. The powdered fertilizer is available commercially and can sustain the growth of a variety of indoor and outdoor vegetation that includes several varieties of fruit and vegetables. Some varieties of oceanic vegetation are extremely fibrous, perhaps with possible future potential to be processed into textile threads. In Genoa, Italy, a certain variety of sea vegetation is processed into paper.
Other edible varieties offer potential of being processed into noodles and “pasta” for human consumption. While one breed of sheep can feed on sea vegetation, there may be scope to test other breeds of farm livestock for their tolerance for oceanic-based livestock feed. There may be scope to process or modify related varieties of oceanic vegetation into feed suitable for livestock.
Many medicines, drugs and dietary supplements are produced after essential material is extracted from certain varieties of plants. There may be future scope to commercially cultivate varieties of sea vegetation for medical purposes.
The Toronto Precedent
During the warm northern summer months, the City of Toronto in Canada uses cold water from near the bottom of Lake Ontario to provide district cooling for a campus of skyscraper office towers and skyscraper hotels located in the city’s business district. The result has been a massive reduction in electrical energy consumption formerly used to operate air-cooled air conditioners. During summer, Toronto is very humid, and the cooling system also extracts massive volumes of near potable water from the humidity, water that may be used to sustain nearby vegetation or be used to refill toilet tanks.
There may be scope for several Australian coastal cities to borrow from the Toronto precedent, the result of the sea floor rapidly dropping off to great depths near the coast. During the southern summer when sea surface temperatures are comfortable for swimming, the water temperature at the greater depths is barely above the freezing point of water. It is technically possible to install insulated pipes from the coast to gain access to the deep cold water and pump it through massive coastal heat exchangers that may be connected to extensive district cooling systems in some large Australian cities.
District Cooling and Humidity
Deep level seawater is located near the coast of such large cities as Sydney, Brisbane, Newcastle and Perth. Overseas, the precedent of undersea pipelines carrying natural gas under high pressure over distances of several hundred miles may be adapted in Australia to gain access to cold, deep level sea water intended for district cooling. A unit volume of water holds some 3,300 times the heat capacity as the identical volume of air at sea level, and during the warm southern summer, air conditioners and industrial refrigerators could be cooled by warn atmospheric air.
Operating water-cooled air conditioners in large buildings in city business districts and industrial refrigerators in industrial areas would greatly reduce summer time electrical consumption. During summer, early morning humidity at some coastal cities can exceed 70 percent, sufficient to operate water-from-air extraction machines. By connecting such machines to a district cooling system, large water-from-air units that include UV-water treatment could produce large amounts of potable water at competitive cost and minimal energy consumption and especially so during periods of drought. A district cooling system allows water-from-air extraction to be highly decentralized over extensive urban areas.
As Australia endures yet another drought, the ocean can offer some regions some relief from the drought. There is space along Australia’s extensive coastline to develop sea farms to commercially cultivate a wide variety of ocean vegetation as both future livestock feed and future raw material to produce paper and textile thread. It may be possible to combine sea vegetation cultivation with commercial raising of several varieties of shellfish. The combination of humidity over 65 percent and a deep sea floor near to the coast offers some Australian coastal cities to operate district cooling systems that in turn sustain the operation of water-from-air extraction technology.
The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.