Seawater desalination in Australia

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Sydney's Northern Beaches. During recent years, Sydney has experienced some freshwater shortages Aerial view of Sydney Northern Beaches.jpg
Sydney's Northern Beaches. During recent years, Sydney has experienced some freshwater shortages

Australia is the driest habitable continent on Earth and its installed desalination capacity has been increasing.[ citation needed ] Until a few decades ago, Australia met its demands for water by drawing freshwater from dams and water catchments. As a result of the water supply crisis during the severe 1997–2009 drought, state governments began building desalination plants that purify seawater using reverse osmosis technology. Approximately one percent of the world's drinkable water originates from desalination plants. [1]

Contents

The first modern large-scale desalination plant was the Perth Seawater Desalination Plant, completed in November 2006 and over 30 plants are currently operating across the country. Many plants are utilizing nearby wind or wave farms to use renewable energy and reduce operating costs, and solar powered desalination units are used for remote communities.[ citation needed ]

Background

Until a few decades ago, Australia met its demands for water by drawing freshwater from dams and water catchments. However, during 2000-2010 a significant lack of rainfall drained water reservoirs. [2] The most affected cities were the capitals, where there is high uncertainty in water supply and demand. In 2007, Sydney, the capital city of New South Wales, experienced a dramatic drop of its main dam Warragamba, where water levels dropped to 33% of normal.

Australia's first desalination plant was constructed in 1903 to treat saline groundwater in the gold fields of Western Australia at Kalgoorlie. [3] Several desalination plants were built in Australia between 1960 and 1980, especially following the revolution in membrane technology that made reverse osmosis economically viable, but vapor-compression desalination and multi-stage flash distillation plants were also built. By 2002, however, only two reverse osmosis desalination plants were still operating, one on Kangaroo Island and the other on Rottnest Island. [2] Seawater reverse osmosis is the only type of desalination technology currently used for large-scale desalination plants in Australia, the most important of these plants being located in Perth and Sydney. [3]

Methods

Compared to existing sources, desalination is considered to be expensive, but research is underway to develop more effective desalination technology. [4] Despite its drawbacks, it is considered a possible solution to the country's water shortages.

Australia is the driest inhabitable continent on earth and its installed desalination capacity is around 1% of the total world's desalination capacity. The Department of Agriculture, Fisheries and Forestry has considered several desalination technologies processes in Australia: [2]

ROSI

A solar powered desalination unit designed for remote communities has been tested in the Northern Territory. The reverse osmosis solar installation (ROSI) uses membrane filtration to provide a reliable and clean drinking water stream from sources such as brackish groundwater. Solar energy overcomes the usually high-energy operating costs as well as greenhouse emissions of conventional reverse osmosis systems. A photovoltaic solar array tracks the Sun and powers the pumps needed to process the water, using the plentiful sunlight available in remote regions of Australia not served by the power grid.

Desalination plants

In Australia many desalination plants are utilizing wind farms to produce enough energy to operate nearby desalination plants. For example, the Kurnell Desalination Plant, with a capacity of producing 250 million liters (ML) of drinking water per day, supplies 15% of Sydney's water needs via RO technology and is powered using "100 percent renewable energy" from the 140 MW Capital Wind Farm. [5] [6] The Garden Island plant, currently planned for commissioning in 2014, will be powered by wave energy, using Carnegie Wave Energy's CETO system. This system uses submerged buoys to pressurize water offshore, which is piped onshore to either drive turbines for electricity generation or as in this case, to directly desalinate seawater. The Garden Island project is a commercial scale demonstration project, which follows a pilot project off the coast of Fremantle, Western Australia [7]

Construction of Adelaide Desalination Plant Port Stanvac Desalination Plant P1000724.jpg
Construction of Adelaide Desalination Plant

The availability of renewable resources as well as their fluctuation in electricity production from region to region requires a customized design for each desalination facility. In order to maintain steady-state operations many facilities utilize renewable energy while connected to a smart grid, importing or exporting energy to the plant as required. The Perth Seawater Desalination Plant utilizes this strategy where 48 wind turbines produce 80MW on the Emu Downs Wind Farm to provide an overall 24MW to the desalination plant. [8] Electrical energy from the renewable energy can also be stored in storage batteries and utilized when needed. As seen in the PV-powered RO system in Gillen Bore, Australia; producing 1,200 L/d. [9] Or if the plant is not required full-time, it can operate using the power as it becomes available. In 2005 a PV-powered hybrid UF/RO filtration system providing 764 liters per day tolerated well power variation from changing weather conditions. [10]

Adelaide

In December 2007, the South Australian government announced it would build the Adelaide Desalination Plant seawater desalination plant for the city of Adelaide, Australia, located at Port Stanvac. The desalination plant was to be funded by raising water rates to achieve full cost recovery. [11] [12]

Perth

About two million people occupy the Perth region in the south western corner of Western Australia. The Perth Seawater Desalination Plant (PSDP) was installed in late 2006 to produce up to 45 gigalitres of potable water per year. In addition, its brine discharge has been shown to have no adverse impact on the environment. The plant buys its power from electricity generated by the Emu Downs Wind Farm, located 200 kilometers north of Perth. The 83 megawatt wind farm consists of 48 wind turbines and contributes over 272 giga-watt-hours (GWhr) per year into the grid, fully offsetting the Perth SWRO Plant's estimated electrical requirement of 180 GWhr per year. [13] The plant has attracted interest from the world's water industry and media, and has won numerous national and international awards including the International Desalination Association's International Desalination Plant of the Year in 2007.

Another seawater desalination plant on the coast about 160 kilometres south of Perth is now operational. This plant is designed to have an initial annual output of 50 gigalitres which later doubled to 100 gigalitres when the project was completed in 2012. [14]

Related Research Articles

<span class="mw-page-title-main">Desalination</span> Removal of salts from water

Desalination is a process that takes away mineral components from saline water. More generally, desalination refers to the removal of salts and minerals from a target substance, as in soil desalination, which is an issue for agriculture. Saltwater is desalinated to produce water suitable for human consumption or irrigation. The by-product of the desalination process is brine. Desalination is used on many seagoing ships and submarines. Most of the modern interest in desalination is focused on cost-effective provision of fresh water for human use. Along with recycled wastewater, it is one of the few rainfall-independent water resources.

Multi-stage flash distillation (MSF) is a water desalination process that distills sea water by flashing a portion of the water into steam in multiple stages of what are essentially countercurrent heat exchangers. Current MSF facilities may have as many as 30 stages.

Solar desalination is a desalination technique powered by solar energy. The two common methods are direct (thermal) and indirect (photovoltaic).

<span class="mw-page-title-main">Osmotic power</span> Energy available from the difference in the salt concentration between seawater and river water

Osmotic power, salinity gradient power or blue energy is the energy available from the difference in the salt concentration between seawater and river water. Two practical methods for this are reverse electrodialysis (RED) and pressure retarded osmosis (PRO). Both processes rely on osmosis with membranes. The key waste product is brackish water. This byproduct is the result of natural forces that are being harnessed: the flow of fresh water into seas that are made up of salt water.

<span class="mw-page-title-main">Reverse osmosis plant</span> Type of water purification plant

A reverse osmosis plant is a manufacturing plant where the process of reverse osmosis takes place. Reverse osmosis is a common process to purify or desalinate contaminated water by forcing water through a membrane. Water produced by reverse osmosis may be used for a variety of purposes, including desalination, wastewater treatment, concentration of contaminants, and the reclamation of dissolved minerals. An average modern reverse osmosis plant needs six kilowatt-hours of electricity to desalinate one cubic metre of water. The process also results in an amount of salty briny waste. The challenge for these plants is to find ways to reduce energy consumption, use sustainable energy sources, improve the process of desalination and to innovate in the area of waste management to deal with the waste. Self-contained water treatment plants using reverse osmosis, called reverse osmosis water purification units, are normally used in a military context.

A solar-powered desalination unit produces potable water from saline water through direct or indirect methods of desalination powered by sunlight. Solar energy is the most promising renewable energy source due to its ability to drive the more popular thermal desalination systems directly through solar collectors and to drive physical and chemical desalination systems indirectly through photovoltaic cells.

<span class="mw-page-title-main">Emu Downs Wind Farm</span> Wind farm in Western Australia

The Emu Downs Wind Farm is a 79.2 MW wind farm in Western Australia. It was a 50:50 joint development between Griffin Energy and Stanwell Corporation. The site is approximately 200 kilometres north of Perth, near Cervantes. Construction of the $180 million project commenced in November 2005, and the project was commissioned in October 2006.

<span class="mw-page-title-main">Perth Seawater Desalination Plant</span>

The Perth Seawater Desalination Plant, located in Naval Base, south of Perth, Western Australia, turns seawater from Cockburn Sound into nearly 140 megalitres of drinking water per day, supplying the Perth metropolitan area.

<span class="mw-page-title-main">CETO</span>

CETO is a wave-energy technology that converts kinetic energy from ocean swell into electrical power and directly desalinates freshwater through reverse osmosis. The technology was developed and tested onshore and offshore in Fremantle, Western Australia. In early 2015 a CETO 5 production installation was commissioned and connected to the grid. As of January 2016 all the electricity generated is being purchased to contribute towards the power requirements of HMAS Stirling naval base at Garden Island, Western Australia. Some of the energy will also be used directly to desalinate water.

<span class="mw-page-title-main">Victorian Desalination Plant</span>

The Victorian Desalination Plant is a water desalination plant in Dalyston, on the Bass Coast in southern Victoria, Australia. The project was announced by Premier Steve Bracks in June 2007, at the height of the millennium drought when Melbourne's water storage levels dropped to 28.4%, a drop of more than 20% from the previous year. Increased winter-spring rains after mid-2007 took water storage levels above 40%, but it was not until 2011 that storages returned to pre-2006 levels.

<span class="mw-page-title-main">Pressure exchanger</span> Device for exchanging pressure between two fluids

A pressure exchanger transfers pressure energy from a high pressure fluid stream to a low pressure fluid stream. Many industrial processes operate at elevated pressures and have high pressure waste streams. One way of providing a high pressure fluid to such a process is to transfer the waste pressure to a low pressure stream using a pressure exchanger.

Richard Lindsay Stover, Ph.D., pioneered the development of the PX Pressure Exchanger energy recovery device Energy recovery that is currently in use in most seawater reverse osmosis desalination plants in existence today.

The Sydney Desalination Plant also known as the Kurnell Desalination Plant is a potable drinking water desalination plant that forms part of the water supply system of Greater Metropolitan Sydney. The plant is located in the Kurnell industrial estate, in Southern Sydney in the Australian state of New South Wales. The plant uses reverse osmosis filtration membranes to remove salt from seawater and is powered using renewable energy, supplied to the national power grid from the Infigen Energy–owned Capital Wind Farm located at Bungendore.

Reverse osmosis (RO) is a water purification process that uses a semi-permeable membrane to separate water molecules from other substances. RO applies pressure to overcome osmotic pressure that favors even distributions. RO can remove dissolved or suspended chemical species as well as biological substances, and is used in industrial processes and the production of potable water. RO retains the solute on the pressurized side of the membrane and the purified solvent passes to the other side. It relies on the relative sizes of the various molecules to decide what passes through. "Selective" membranes reject large molecules, while accepting smaller molecules.

<span class="mw-page-title-main">Adelaide Desalination Plant</span>

The Adelaide Desalination plant (ADP), formerly known as the Port Stanvac Desalination Plant, is a sea water reverse osmosis desalination plant located in Lonsdale, South Australia which has the capacity to provide the city of Adelaide with up to 50% of its drinking water needs.

<span class="mw-page-title-main">Southern Seawater Desalination Plant</span> Plant supplying water to Perth, Western Australia

The Binningup Desalination Plant is a desalination plant near Binningup, Western Australia, about 150 kilometres (93 mi) south of Perth. It supplies water to the state capital Perth, as well as the nearby regional city of Bunbury and is known as the Southern Seawater Desalination Project It was designed to initially deliver 50 gigalitres of potable water per year but was expanded to deliver 100 gigalitres of potable water per year, or 33% of Perth's requirements. The plant was officially opened in September 2011 at reduced output, and was completed and operating at full capacity in January 2013.

The Capital Wind Farm near Bungendore is the largest wind farm in New South Wales. It is part of the 6,000-hectare (15,000-acre) Capital Renewable Energy Precinct, along with nearby Woodlawn Wind Farm and the Capital East Solar Demonstration Plant.

There are approximately 16,000 operational desalination plants, located across 177 countries, which generate an estimated 95 million m3/day of fresh water. Micro desalination plants operate near almost every natural gas or fracking facility in the United States. Furthermore, micro desalination facilities exist in textile, leather, food industries, etc.

The low-temperature distillation (LTD) technology is the first implementation of the direct spray distillation (DSD) process. The first large-scale units are now in operation for desalination. The process was first developed by scientists at the University of Applied Sciences in Switzerland, focusing on low-temperature distillation in vacuum conditions, from 2000 to 2005.

References

  1. "Desalination – Past, Present and Future". International Water Association. Retrieved 19 November 2019.
  2. 1 2 3 El Saliby, I., Y. Okour, et al. (2009). "Desalination plants in Australia, review and facts." Desalination 247(1-3): 1–14.
  3. 1 2 Heath, J. "The Water Supply in Hearth Australia." July 2007 Web. 28 April 2010 <http://www.viacorp.com/perth_water.htm>
  4. Desalination options and their possible implementation in Western Australia] CSIRO June 2006
  5. Desalination Sydney Water
  6. Kurnell Desalination Plant, Australia. n.d. Web. 28 April 2010. <http://www.water-technology.net/projects/kurnell-desalination/>
  7. "Home". carnegiewave.com.
  8. Perth Seawater Desalination Plant, Seawater Reverse Osmosis (SWRO), Kwinana, Australia". Water-Technology. n.d. Web. 28 April 2010. <http://www.water-technology.net/projects/perth/>
  9. Ghermandi,A., and Messalem, R. "Solar-driven desalination with reverse osmosis: the state of the art". Desalination and Water Treatment 7 (2009) 287
  10. De Munari, A., Capäo, D.P.S., Richards, B.S., and Schäfer, A.I. "Application of solar-powered desalination in a remote town in South Australia". Desalination (1987) 67:81–95
  11. Water prices to rise and desalination plant set for Port Stanvac News.com.au 4 December 2007
  12. Desalination plant for Adelaide. ministers.sa.gov.au. 5 December 2007
  13. "Environmentally sound desalination at the Perth seawater desalination plant" by Richard Stover, Gary Crisp Energy Recovery, Inc., San Leandro, California, USA. Retrieved on 2 May 2010 from http://www.energyrecovery.com/UserFiles/file/archives/news/documents/ThePerthSaltwaterDesalinationPlant.pdf
  14. "Water Corporation". www.watercorporation.com.au. Archived from the original on 10 June 2023. Retrieved 17 June 2023.