Cities turn to desalination for water security, but at what cost?



File 20190207 174873 kcdlxk.jpg?ixlib=rb 1.1
The largest desalination plant in Australia, Victoria’s A$3.5 billion ‘water factory’ can supply nearly a third of Melbourne’s needs.
Nils Versemann/Shutterstock

Ian Wright, Western Sydney University and Jason Reynolds, Western Sydney University

This is the first of two articles looking at the increasing reliance of Australian cities on desalination to supply drinking water, with less emphasis on alternatives such as recycling and demand management. So what is the best way forward to achieve urban water security?


Removing salts and other impurities from water is really difficult. For thousands of years people, including Aristotle, tried to make fresh water from sea water. In the 21st century, advances in desalination technology mean water authorities in Australia and worldwide can supply bountiful fresh water at the flick of a switch.

Achieving water security using desalination is now a priority for the majority of Australia’s capital cities, all but one of which are on the coast. Using the abundance of sea water as a source, this approach seeks to “climate proof” our cities’ water supplies.




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It’s hard to believe now that as recently as 2004 all Australian capital city water authorities relied on surface water storage dams or groundwater for drinking water supplies. Since Perth’s first desalination plant was completed in 2006, Australian capital cities have embraced massive seawater desalination “water factories” as a way to increase water security.

Perth and Adelaide have relied most on desalination to date. Canberra, Hobart and Darwin are the only capitals without desalination.

The drought that changed everything

From the late 1990s to 2009 southeastern Australia suffered through the Millennium Drought. This was a time of widespread water stress. It changed the Australian water industry for ever.

All major water authorities saw their water storages plummet. Melbourne storages fell to as low as 25% in 2009. The Gosford-Wyong water storage, supplying a fast-growing area of more than 300,000 people on the New South Wales Central Coast, dropped to 10% capacity in 2007.

These were familiar issues in locations such as Perth, where the big dry is epic. For more than four decades, the city’s residents have been watching their supply of surface water dwindle. Remarkably, only about 10% of Perth’s water now comes from this source.

Perth’s two desalination plants have a combined output of up to 145 billion litres (gigalitres, GL) a year. That’s nearly half the city’s water needs. Both have remained in operation since they were built.




Read more:
Is Perth really running out of water? Well, yes and no


Modern industrial-scale desalination uses reverse osmosis to remove salt and other impurities from sea water. Water is forced under high pressure through a series of membranes through which salt and other impurities cannot pass.

Design, construction and maintenance costs of these industrial plants are high. They also use massive amounts of electricity, which increases greenhouse gas emissions unless renewable energy sources are used.

Another concern is the return of the excess salt to the environment. Australian studies have shown minimal impact.




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Just as many of the massive new desalination factories were completed, and proudly opened by smiling politicians, it started raining. The desalination plants were switched off as storages filled. However, water consumers still had to pay for the dormant plants to be maintained – hundreds of millions of dollars a year in the case of the Melbourne and Sydney plants.

Bringing plants out of mothballs

Now drought has returned to southeast Australia. Once again, many capital city water storages are in steep decline. So what is the response of water authorities in the desal age? Not surprisingly, more desalination is their answer.

One by one the desalination plants are being switched back on. Sydney has just begun the process of restarting its plant, which was commissioned in 2010. Adelaide has plans to greatly increase the modest output from its plant this year. The Gold Coast plant, which can also supply Brisbane, is operating at a low level in “hot standby” mode.

After a dry winter, Melbourne Water is expected to advise the Victorian government to make the largest orders for desalinated water since its plant, able to produce 150GL a year, was completed in December 2012. Mothballed for more than four years, it supplied its first water to reservoirs in March 2017. The previously forecast need for 100GL in 2019-20 (annual orders are decided in April) is almost one-quarter of Melbourne’s annual demand. Plant capacity is capable of being expanded to 200GL a year.

When bushfires recently threatened Victoria’s largest water storage, the Thomson dam, the government said desalinated water could be used to replace the 150GL a year taken from the dam.

Sydney’s plan for future droughts is to double the output of its desalination plant from 250 million litres (megalitres, ML) a day to 500ML a day. This would take its contribution from 15% to 30% of Sydney’s water demand.

Perth, Adelaide, Melbourne, Brisbane and the Gold Coast already have the capacity to supply larger proportions of their populations with desalinised water as required.

What about inland and regional settlements across Australia? Large-scale desalination plants may not viable for Canberra and other inland centres. These regions would require sufficient groundwater resources and extraction may not be environmentally sound.

How much, then, do we pay for the water we use?

The plants supplying our biggest cities cost billions to construct and maintain, even when they sit idle for years.

The Australian Water Association estimates the cost of supplying desalinated water varies widely, from $1 to $4 per kL.

In fact, water costs in general vary enormously, depending on location and how much is used. The pricing structures are about as complex as mobile phone plans or health insurance policies.

The highest price is in Canberra where residents pay $4.88/kL for each kL they use over 50kL per quarter. The cheapest rate is Hobart’s $1.06/kL.

The issue of water pricing leads on to the question of what happened to the alternative strategies – recycling and demand management – that cities pursued before desalination became the favoured approach? And how do these compare to the expensive, energy-hungry process of desalination? We will consider these questions in our second article.


This article has been updated to clarify the status of advice on Melbourne’s use of desalinated water.The Conversation

Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University and Jason Reynolds, Research Lecturer in Geochemistry, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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We can’t know the future cost of climate change. Let’s focus on the cost of avoiding it instead



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Economists have searched for the mythical balance between the cost of climate action, and the future cost of doing nothing.
Joop Hoek/Shutterstock.com

Jack Pezzey, Australian National University

As delegates at the UN climate summit in Katowice, Poland, discuss the possibility of restraining global warming to 1.5℃, it might sound like a reasonable question to ask how much money it will cost if they fail.

Economists have spent the past 25 years trying – and largely failing – to agree on the “right” answer to this question. It’s an important consideration, because governments are understandably keen to balance the benefits of limiting long-term climate damage with the more immediate costs of reducing greenhouse emissions.

In simple economics terms, we can ask what price would be worth paying today to avoid emitting a tonne of carbon dioxide, given the future damage costs that would avoid.

This mythical figure has been called the “social cost of carbon”, and it could serve as a valuable guide rail for policies such as carbon taxes or fuel efficiency standards. But my recent research suggests this figure is simply too complicated to calculate with confidence, and we should stop waiting for an answer and just get on with it.




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While some climate economists have put the social cost of carbon at hundreds or even thousands of dollars per tonne of CO₂, one of the most influential analyses, by Yale University economist William Nordhaus, offers a much more modest figure of just over US$30.

Nordhaus won this year’s Nobel Prize in Economics, but his analysis has some uncomfortable conclusions for those familiar with the science.

At this level, it will be economically “optimal” for the world to reduce its CO₂ emissions quite slowly, so that global warming peaks at about 4℃ some time next century. But this certainly doesn’t sound optimal from a scientific perspective.

Reconstructed global mean temperature anomalies for 0–2000 CE, and DICE-2016R projections for 2015–2400.
CREDIT, Author provided

The impossibility of knowing the social cost of carbon

Calculating this magical economic balancing point is the holy grail of climate economics, and sadly it also seems to be an impossible task, because the question is so complex as to be unanswerable.

Why so? Normally, we gain knowledge via three main methods. The first option is to design an experiment. If that’s impossible, we can look for a similar case to observe and compare. And if that too is impossible, we can design a model that might hopefully answer our questions.

Generally, the laws of physics fall into the first category. It’s pretty straightforward to design an experiment to demonstrate the heat-trapping properties of CO₂ in a lab, for instance.

But we can’t do a simple experiment to assess the global effects of CO₂ emissions, so instead climatologists have to fall back on the second or third options. They can compare today’s conditions with previous fluctuations in atmospheric CO₂ to gauge the likely effects. They also design models to forecast future conditions on the basis of known physical principles.

By contrast, economists trying to put a dollar value on future climate damage face an impossible task. Like scientists, they cannot usefully test or make comparisons, but the economic effects of future climate change on an unprecedented 10 billion people are too fiendishly complex to model with confidence.

Unlike the immutable laws of physics, the laws of economics depend on markets, which in turn rely on trust. This trust could break down in some catastrophic future drought or deluge. So economists’ various rival calculations for the social costs of carbon are all based on unavoidable guesswork about the value of damage from unprecedented future warming.

This view is understandably unpopular with most climate economists. Many new studies claim that recent statistical techniques are steadily improving our estimates of the value of climate damage, based mainly on the local economic effects of short-run temperature and other weather changes in recent decades.

But so far, the world has experienced only about 1℃ of global warming, with at most 0.3℃ from one year to the next. That gives us almost no way of knowing the damage from warming of 3℃ or so; it may turn out to be many times worse than projected from past damage, as various tipping points are breached.

Focus on emission reduction, not damage cost

One reason why economists keep trying to value climate damage is a 1993 US Presidential Executive Order that requires cost-of-carbon estimates for use in US regulations. But my findings support what many other climate economists have been doing anyway. That is to build models that ignore the future dollar cost of climate damage, and instead look at feasible, low-cost ways to cut emissions enough to hit physical targets, such as limiting global warming to 1.5℃ or 2℃, or reaching zero net emissions by 2100.

Once we know these pathways, we don’t need to worry about the future cost of climate damage – all we need to ask is the cost of reducing emissions by a given amount, by a given deadline.

Of course, these costs are still deeply uncertain, because they depend on future developments in renewable energy technologies, and all sorts of other economic factors. But they are not as fiendishly uncertain as trying to pin a dollar value on future climate damage.




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Focusing on the cost of emissions-reduction pathways allows researchers to put their effort into practical issues, such as how far and fast countries can shift to zero-emission electricity generation. Countries such as Sweden and the UK have already begun implementing this kind of action-oriented climate policies. While far from ideal, they are among the best-ranked major economies in the Climate Change Performance Index. Australia, by contrast, is ranked third worst.

But aren’t trillion-dollar estimates of future warming damage, as featured in the recent US Fourth National Climate Assessment, necessary ammunition for advocates of climate action? Maybe, but it is still important to appreciate that these estimates are founded on a large chunk of guesswork.

Setting climate targets will always be a political question as well as a scientific one. But it’s an undeniably sensible aim to keep climate within the narrow window that has sustained human civilisation for the past 11,000 years. With that window rapidly closing, it makes sense for policymakers just to focus on getting the best bang for their buck in cutting emissions.The Conversation

Jack Pezzey, Senior Fellow, Fenner School of Environment and Society, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

India unveils the world’s tallest statue, celebrating development at the cost of the environment


Ruth Gamble, La Trobe University and Alexander E. Davis, La Trobe University

India’s Prime Minister Narendra Modi will today inaugurate the world’s largest statue, the Statue of Unity in Gujarat. At 182m tall (240m including the base), it is twice the height of the Statue of Liberty, and depicts India’s first deputy Prime Minister, Sardar Vallabhbhai Patel.

The statue overlooks the Sardar Sarovar Dam on the Narmada River. Patel is often thought of as the inspiration for the dam, which came to international attention when the World Bank withdraw its support from the project in 1993 after a decade of environmental and humanitarian protests. It wasn’t until 2013 that the World Bank funded another large dam project.

Like the dam, the statue has been condemned for its lack of environmental oversight, and its displacement of local Adivasi or indigenous people. The land on which the statue was built is an Adivasi sacred site that was taken forcibly from them.




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The Statue of Unity is part of a broader push by Modi’s Bharatiya Janata Party (BJP) to promote Patel as a symbol of Indian nationalism and free-market development. The statue’s website praises him for bringing the princely states into the Union of India and for being an early advocate of Indian free enterprise.

The BJP’s promotion of Patel also serves to overshadow the legacy of his boss, India’s first prime minister, Jawaharlal Nehru. Nehru’s descendants head India’s most influential opposition party, the Indian National Congress.

The statue was supposed to be built with both private and public money, but it attracted little private investment. In the end, the government of Gujarat paid for much of the statue’s US$416.67 million price tag.

The statue under construction, January 2018.
Alexander Davis

The Gujarat government claims its investment in the statue will promote tourism, and that tourism is “sustainable development”. The United Nations says that sustainable tourism increases environmental outcomes and promotes local cultures. But given the statue’s lack of environmental checks and its displacement of local populations, it is hard to see how this project fulfils these goals.

The structure itself is not exactly a model of sustainable design. Some 5,000 tonnes of iron, 75,000 cubic metres of concrete, 5,700 tonnes of steel, and 22,500 tonnes of bronze sheets were used in its construction.

Critics of the statue note that this emblem of Indian nationalism was built partly with Chinese labour and design, with the bronze sheeting subcontracted to a Chinese firm.

The statue’s position next to the controversial Sardar Sarovar Dam is also telling. While chief minister of Gujarat from 2001 to 2014, Modi pushed for the dam’s construction despite the World Bank’s condemnation. He praised the dam’s completion in 2017 as a monument to India’s progress.

Both the completion of the dam and the statue that celebrates it suggest that the BJP government is backing economic development over human rights and environmental protections.

The statue’s inauguration comes only a month after the country closed the first nature reserve in India since 1972. Modi’s government has also come under sustained criticism for a series of pro-industry policies that have eroded conservation, forest, coastal and air pollution protections, and weakened minority land rights.

India was recently ranked 177 out of 180 countries in the world for its environmental protection efforts.

Despite this record, the United Nations’ Environmental Programme (UNEP) recently awarded Modi its highest environmental award. It made him a Champion of the Earth for his work on solar energy development and plastic reduction.

The decision prompted a backlash in India, where many commentators are concerned by the BJP’s environmental record.




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Visitors to the statue will access it via a 5km boat ride. At the statue’s base, they can buy souvenirs and fast food, before taking a high-speed elevator to the observation deck.

The observation deck will be situated in Patel’s head. From it, tourists will look out over the Sardar Sarovar Dam, as the accompanying commentary praises “united” India’s national development successes.

But let’s not forget the environmental and minority protections that have been sacrificed to achieve these goals.


This article was amended on November 7, 2018, to clarify the role of Chinese companies in the statue’s design and construction.The Conversation

Ruth Gamble, David Myers Research Fellow, La Trobe University and Alexander E. Davis, New Generation Network Fellow, La Trobe University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How much does wind energy cost? Debunking the myths


Dylan McConnell, University of Melbourne

Are renewables pushing up the cost of electricity? That’s the claim made by Alan Moran in an opinion piece for the Australian Financial Review this week.

Moran, executive director of Regulation Economics and a former director at the Institute of Public Affairs, argues that increasing investment in renewables and particularly wind energy will cost consumers billions of dollars. The high operating costs and requirements for backup when the wind isn’t blowing are the problem, he argues.

But the evidence actually suggests the opposite: wind energy is already competitive with fossil fuels, will reduce electricity prices for consumers, and will play a large role in reducing Australia’s greenhouse gas emissions.

So, let’s go through Moran’s claims one by one.

Claim: [W]indfarms […] need three times the price at which Australian coal generators can supply electricity. Australia’s coal resources are so abundant that across the eastern states that they can profitably supply electricity at a cost of $40 a MWh. Windfarms require $120 a MWh.

It is true that black coal can supply electricity to the wholesale market at A$40 per megawatt hour (MWh). However, new wind farms require much less than A$120 per MWh to be financed. Recent experience shows that new wind farms require A$80-90 per MWh.

But this is comparing apples with oranges. The coal cost refers to what is essentially the cost of fuel. The wind cost is the cost over the lifetime of the project, including capital and return on investment.

If we compare apples with apples, the long-run cost of coal is A$85-$100 per MWh (without a carbon price), versus A$90 per MWh for wind. The short-run cost of wind is zero: flowing air costs nothing.

Claim: [B]ecause wind generated supply is intrinsically unreliable it needs back-up in the form of fast start generators […] Wind/solar generation in Australia currently has a 7% share of supply. That level requires 6 per cent in additional back-up, according to the estimates by the Australian Energy Market Operator.

This statement implies that additional capacity has had to be installed because of wind. This is demonstrably not true. The Australian Energy Market Operator has stated that there is no new capacity required in the next 10 years, despite the increase in wind and solar.

South Australia is a good example. More than 1,200 megawatts of wind power capacity has been installed, but virtually no new gas plants have been built as “backup”. In the chart below you can see that on the afternoon and evening of Sunday June 7, wind and gas met all electricity demand in South Australia.

Generation by fuel type in South Australia on Sunday the 7th of June 2015. Operations at the Northern Power Station were shut down after an explosion at around midday.

More broadly, redundant capacity is important in the entire electricity system (not just wind). All types of generation have planned and unplanned shortages.

Unplanned outages are more challenging. If a whole generator goes offline, the system must return to normal within five minutes. This is often achieved with a “fast start” generator such as a gas turbine or hydro plant. These contingency plans must equal the loss of the largest generator in the system, usually coal.

No technology is 100% reliable, as illustrated in the graph above. Wind is really quite predictable and reliable compared to coal.

Claim: Wind turbine development has been improved over the past 20 years but is now approaching its theoretical maximum efficiency. It will never be remotely price competitive with conventional generators notwithstanding wishful thinking.

As I’ve shown above, wind is already competitive with new-build coal (and gas) in Australia, and many other places around the world (including the United States). Carbon policy aside, some of the assets are seriously old and are going to be retired anyway.

A new study from UNSW Australia looked at the best energy mix for generation. Even without a carbon price, the research found that the lowest cost mix in 2050 sources only 30% of electricity from gas, with the rest supplied by renewables. About half of the gas capacity is Open Cycle Gas Turbines (for peak demand) that supply very small quantities of energy.

Claim: In aggregate terms, the annual impost on electricity consumers [of the Renewable Energy Target] is therefore from the 33,000GWh and means a cost to the customer of $3 billion a year […]

As I’ve written before on The Conversation, the government’s own modelling shows a net saving to consumers (and so does plenty of other analysis). The ACIL Allen analysis finds the target will cut power bills from 2021 onwards (by up to A$91 per year by 2030) and deliver a net saving to consumers.

Claim: Energy only comprises 25 to 30 per cent of emissions and Australia’s renewable target might therefore reduce emissions by 4 to 5 per cent.

According the Climate Change Authority’s review of the Renewable Energy Target (RET), the RET is projected to reduce Australia’s overall emissions by 58 million tonnes of CO2-equivalent.

The Government’s latest estimate of Australia’s emissions reduction task between 2015 and 2020 is 421 million tonnes. So between 2015 and 2020 alone, the RET achieves at least 13% of the reduction task.

The Conversation

Dylan McConnell is Research Fellow, Melbourne Energy Institute at University of Melbourne.

This article was originally published on The Conversation.
Read the original article.

Australia: Green Energy Cheaper


The link below is to an interesting article that reports on the cost of electricity generation in Australia.

For more visit:
http://news.mongabay.com/2013/0208-wind-power-australia.html

Australia: Victoria – Melbourne


The link below is to an article that looks at the cost of climate change for Melbourne in Victoria, Australia.

For more visit:
http://www.theage.com.au/victoria/climate-change-bill-of-1b-for-suburbs-20121020-27yli.html