Saturday, 31 May 2008

Nuclear energy for mitigation as well as adaptation

In an article titled Squaring up to Reality in Nature Reports, an online outlet of the journal Nature, Martin Parry, Jean Palutikof, Clair Hanson and Jason Lowe discuss the risks, realities and likely outcomes of different emission reduction scenarios.

Nature is a well respected scientific magazine. Martin Parry, Jean Palutikof and Clair Hanson led the impacts assessment for the IPCC, as co-chair, head and deputy head, respectively, of the Technical Support Unit of Working Group II. Jason Lowe is a climate scientist in the UK Met Office and provided the underlying scenarios used in the report.

When they discuss countries most likely to be impacted by climate change...?
We are now probably witnessing the first genuinely global effects of greenhouse gas warming. The steep increases in food prices around the world are the result of rising costs and demand aggravated by drought in food-producing regions — in the case of Australia, probably due in part to global warming — and by a poorly conceived experiment in climate policy that has converted cropland to bio-fuel plantations. This should serve as a wake-up call: impacts of climate change can surprise us, especially when they act in combination with other pressures.
Carbon emission reductions of 50–80% below 1990 levels are considered, but what interests me most is their call for a blend of mitigation as well as adaptation - specifically to meet global water needs. Even with a 50% reduction by 2050, 1 billion people will be without water. 80% cuts will half that number, but clearly adaptation measures are needed as well as those to mitigate, or achieve the cuts in the first place.

I have invested a large quantity of keystrokes discussing nuclear power's potential role to help Australia satisfy no/low carbon energy demands and, with other technologies and programmes, meet the relevant emission reduction targets. However, I have not spent much time on nuclear power's role in adaptation.

Nuclear desalination is the first application that springs to mind. According to the WNA, there are currently around 12,500 desalination plants operating today producing 30 million m3/day of potable water. Most of these energy intensive plants rely on fossil fuels, but there are nuclear desalination plants operating in Kazakhstan, India and Japan. In total these plants have over 150 reactor years of experience.

Sydney Water's desalination project in Kurnell, NSW is promoting itself as 100 percent renewable powered. But if you watch their promotional video you will see this argument is made by saying new wind-farms will be built with at least as much capacity as that required to operate the desalination plant. These wind turbines will supply energy to the national grid and the desalination plant will draw energy from this grid. I don't want to bash wind. However, the potential for energy executives and politicians to 'double-dip' may be too tempting to resist. For example: if, during the new windfarm's ribbon cutting ceremony the turbines are heralded as boosting the countries commitment to emissions reductions - but then all this capacity is required to operate the new desalination plant down the road - which emissions have been reduced?

Reverse osmosis [the technology being implemented by Sydney Water] draws 4–6 kW per cubic metre of water produced. Per the project approval document, the capacity is to be 500,000 m3/day. That's about 100 MWe per hour of electrical power. This power could be supplied by around 50 largish wind turbines if/when the wind is blowing at the design velocity. More turbines [or other sources of energy] would be required when the wind is light. I believe this is the plan being promoted by Sydney Water.

An alternate approach would be to co-locate nuclear power and desalination plants on the Australian coast. In this case the desalination plant uses the excess power available during off-peak times of the day/week since most if not all nuclear plant operators prefer to run the plants at full capacity around the clock. It's another energy strategy for consideration. The wind turbines would still be built and together with nuclear power, they could actually displace some carbon emissions while improving overall energy [as well as water] quality and reliability.

One-hundred MWe is about 6–10% of a large modern nuclear power plant's capacity. Water generating capacity could go well beyond the planned capacity for Kurnell should Australia need significantly more water to, for example, shore up the beleaguered agriculture industry.


  1. Reactor waste heat can be used for desalination. waste heat represents a free source of energy, that is now dumped into the environment.

  2. This is something separate from [and/or in addition to] using electricity generated by the plant to run a desalination plant. It improves overall plant efficiency and is therefore a more sustainable approach.

    Also, waste heat is used for district heating applications in cooler areas of the world.

    Thanks Charles.

  3. BHP Billiton have said they need an extra 690 MW in South Australia presumably including the desalination plant at Pt Bonython near Whyalla. The water will be pumped 300 km to Olympic Dam. Some suggested granite geothermal could supply the power but that looks unlikely. If they use carbon power such as precious natgas it will play into the hands of nuclear critics. Of course a 1000 MW plant would have a handy surplus to export to the grid.

  4. Thanks John. I fully agree with your comment.

    Industry requires power and I believe those who would argue the downside of nuclear by citing its mining energy requirement would [or should, for the sake of consistency] see similar negatives for other heavy industry such as steel works, aluminium smelting, etc. This ‘back to the stone age’ mentality is shared by a vocal minority but is not broadly shared by the general public [i.e. people will not voluntarily forgo their favourite toys, but must be made to feel some pain to make any statistically significant cuts – case in point, petrol prices].

    We need more energy and will continue to require additional capacity to account for both increasing demand as well as the closure of ageing generation facilities [even in the context of aggressive conservation, efficiency and renewable deployment initiatives]. To achieve the other relevant constraints such as emission reductions as well as power quality and reliability – nuclear must be part of that package.