When will water use enter power generation debate?

Perhaps Ontario doesn’t have to worry as much because it sits along Lake Ontario and Lake Erie, but I’m surprised that in other jurisdictions there hasn’t been more discussion related to the water requirements of thermoelectric power plants.

Water scarcity, after all, is considered one of the biggest negative outcomes of climate change, but not many people realize just how much water is required for a nuclear or coal (fossil fuel) power plant. The World Resources Institute estimates that nearly two out of every three gallons of fresh water drawn from the U.S. Southeast Southwest is used to cool power plants. One can draw similar conclusions for other regions. Nuclear plants, of course, are the biggest water hogs. You’ll recall that during the heat waves in Europe a few years back France had to ratched down nuclear output because it didn’t have enough water for cooling. It makes one wonder whether it makes sense to build hundreds of new nuclear plants, each with a life of more than 50 years, if a couple of decades down the road we find them crippled by water shortages.

Think about it: If a massive coal plant or nuclear plant had to pay for the amount of water it consumes, the same way individual homeowners must pay, the power would be prohibitively expense. So emissions aren’t the only thing not currently priced into power generation. Water use is a huge externality, and it’s just one more reason to favour renewables and distributed generation, particularly as part of any climate-change adaptation strategy.

Food for thought.

15 thoughts on “When will water use enter power generation debate?”

  1. Another major cause for concern is the effect losing glaciers and summer snowpack will have on flow through rivers with hydroelectric dams. If the flow of rivers like the Columbia was substantially reduced, we would need to find a lot more power in other places.

  2. The Candu plants, at least, don’t use cooling towers. The lakewater is heated and returned to the lake. So they actually don’t consume any water – they just depend on the lake level remaining steady!

  3. Nuclear generating plants in Ontario use water from the lake to cool the reactors, then put it back into the lake. It is not consumed, diverted or turned to vapour. You might argue the negative effects of increasing the water temperature but the same volume that is taken from the lake is returned. In France, I believe the problem was that they cool the water by evaporation in the huge cooling towers that dominate the landscape for miles. They do change river or lake water to vapour released to the atmosphere, we do not.

  4. That’s why I said Ontario doesn’t have to worry because of its position on Lake Ontario. It’s a large enough body of water that it can sustain the release of slightly warmer water. That said, increased water temperature has caused algae growth problems in water intake areas that on several occasions have forced temporary but unplanned reactor shutdowns.

  5. One correction: the article describes the Southeast, not the Southwest. It would be interesting to see the numbers for the Southwest, due to the lack of water resources. But if it’s problem in the Southeast, it’s bound to crop up in the Southwest, especially in a state like Utah that uses mostly coal power plants.

  6. Power plant water issues are complex and much engineering can be done to conserve water. Like almost all things built, power plants use the economically cheapest design at the time it was built. Prices and costs change for materials and resources all the time, resulting in a different “ideal” design over time. That said, there are many types of cooling towers and you can build ones that are optimized for conservation of water. One of the most disappointing attributes of almost all power plant designs is that more energy is thrown away (as low grade heated water in most cases), than is sent out as electrical power. My understanding is that (at least in the US) offering low grade thermal resources was not considered economically relevant when liability issues related to third parties were taken into consideration.

  7. Makes sense. Let’s hope Smitherman & co take this into account before they give the green light for the 2 new reactors planned as part of the Green Energy Act.

  8. It is true that almost all power plants use water for cooling and return it – or it is evaporated. The bad news is that most of the plants, including nuclear are less than 40% efficient – so most of the enery produced is actually going into the cooling water – not electricity…. Consider the coal burners – not only do they use the the same (or more) water for cooling as the nukes. They also polute..

    Interesting stat on water appeared in the Economist a few weeks ago – the average person drinks about 2-3 litres per day – but the food that they eat each day consumes 2,000 – 3,000 litres to produce.

    I agree with the need to conserve water – but the nukes may be a bad place to start. At least the energy that they produce is clean. We might be a lot better off to look at growing lower water consuming plants – as Australia has apparently had to do – and try to buy food that comes from this continent – or nearer…

  9. Stop the craziness! Ontario must stay away from spending money on nukes, even though they do not waste Lake fresh water.

    http://www.nytimes.com/2009/05/29/business/energy-environment/29nuke.html?scp=1&sq=Finland%20Nuclear%20trouble&st=cse

    The plant the arti-link above describes planned to cool with the Baltic Sea. They were also studying how this excess heat was going to change the ecosystem. These heat pools attract a lot of strange animals and plants.

    http://www.stuk.fi/stuk/tiedotteet/2002/en_GB/news_240/

    Nuke heat is a resource that is untapped which, in a cold country, can use to heat cities. It is due time we stop wasting the heat into the lake and drawing from it to warm buildings and homes. Imagine the amount of natural gas we could save.

  10. I wonder if there wouldn’t be a way to use ocean water to cool a power plant and condense the steam to make drinking water… There must be some way to harness the energy that is being injected into water for the greater good…

  11. In reply to Colin – using ocean water in a power plant and capturing the condensed steam is what desalination plants do – common practice in the Arabian Gulf.

    Comment: Water vapor is the predominant green house gas, and (I assume) the majority of steam turbine power plants, whether nuclear, gas or coal fired, release thousands of tons of water vapor to the atmosphere. Am I right? If so, why don’t they talk about this in the global warming debates?

  12. A few points:
    (1) Fresh water used for cooling by electricity generators is mostly returned to river and lakes, however the increased temperature does result in more water being lost to evaporation and the increased temperature has effects on ecosystems. Power plants may have to shut down if lake or river water getting too hot.
    (2) Nuclear plants use more water for cooling than coal plants per kilowatt-hour of electricity produced as they are less efficient than coal plants due to their lower operating temperatures.
    (3) The earth is about 71% ocean. The amount of water vapour added to the atmosphere by electricity generation is trivial compared to the action of sunlight and wind on these huge bodies of water.

  13. Are there any viable methods of power generation using water that do not creat heat and can be used for both personal and commercial applications?

  14. There is major confusion among environmentalists about what water use really is. As pointed out in the comments, you have to look at the amount of water that actually evaporates, which is actually relatively small both for once through as well as for evaporative wet cooling. We are talking about a couple percent of total water CONSUMPTION. Consumption meaning: water that is lost through evaporation or so dirty that it needs major cleaning in water processing plants…

    There is no water shortage, there is a problem about division. Piping in desalinated seawater to arid inland areas is a good solution that is absolutely affordable for a rich country like the US. (percentage of income spent on water is tiny).

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