Even in the North, 2018 Heat Wave Curbs Nuclear Output

August 8, 2018



This year’s unusually warm summer in the Nordic region has increased sea water temperatures and forced some nuclear reactors to curb power output or shut down altogether, with more expected to follow suit.

The summer has been 6-10 degrees Celsius above the seasonal average so far and has depleted the region’s hydropower reservoirs, driving power prices to record highs, boosting energy imports from continental Europe and driving up consumer energy bills.

Nuclear plants in Sweden and Finland are the region’s second largest power source after hydropower dams and have a combined capacity of 11.4 gigawatts (GW).

Reactors need cold sea water for cooling but when the temperature gets too high it can make the water too warm for safe operations, although the threshold varies depending on the reactor type and age.

Unscheduled power output cuts in Swedish and Finnish reactors could push prices even higher, said Vegard Willumsen, section manager at Norway’s energy regulator NVE.

“If nuclear reactors in the Nordics shut down or reduce power due to the heatwave, it could also put pressure on the supply and consequently on the Nordic power prices,” he added.

Electric Light and Power:

As Europe struggles through a major heat wave, the French energy company EDF says it has halted a fourth nuclear reactor, this time one at the country’s oldest nuclear plant at Fessenheim in eastern France.

In a statement, EDT said the Fessenheim nuclear reactor was temporarily shut down Saturday.

Since Thursday, four French nuclear reactors in three power plants near the Rhine and the Rhone Rivers, including Fessenheim, have had to be temporarily shut down. EDF said the decision was made to avoid overheating the rivers.

Nuclear power plants use water from the rivers to cool down the temperatures of their reactors before sending the water back into the rivers. Rivers that are unusually warm can experience mass fish die-offs, which has happened in Germany in the past week.


26 Responses to “Even in the North, 2018 Heat Wave Curbs Nuclear Output”

  1. Gingerbaker Says:

    Another brick in the wall for nuclear.

    Science predicted problems with hydro and nuclear because of heat and drought – and the concerning cavalcade of reality is in upswing.

    Meanwhile, back at the farm, solar and wind could care less.

    • jfon Says:

      Hot weather can reduce solar photovoltaic output by 25% or more – more than the heat-related reduction in nuclear output overall in any country where it’s a major player. As for wind, in the UK, during the heat wave, the wind farms produced almost no power for the first week of this month; Germany and the Low Countries were also well below average output. There is no real cure for that – if it’s not windy, you can’t make wind power. One of the effects of climate change is a slower jet stream, causing blocking highs over much of Europe, and so long periods of little wind output, combined with extra power demand for air conditioning in summer, or heating in winter.
      With nuclear, you can build a cooling tower, extend sea intakes to deeper water, or dig spent water canals. Newer designs will run at higher temperatures, cutting the amount of cooling they need in half.

      • Gingerbaker Says:

        And colder weather increases those panels efficiency by the same amount. So, back to the stated overall output. Unless they are thin-film panels, which don’t share these problems.

        And, if you can propose hugely expensive additions to nuclear plants to make them run at all during heat waves, I can propose cheap additions to solar panels to make up for the small losses during elevated heat:

        * air cooling
        * water cooling
        * adding 25 percent more panels

        You make it sound like a dire situation for PV, which it isn’t. But no output at all from a hundred billion dollar nuke plant? – disaster.

        And this doesn’t even take into consideration what we could accomplish with environmentally-designed panels or nuke plants. The problem is – no one is building better-designed nuke plants. No one is building any nuke plants, so your suggestions are moot.

        Someday, if say, a large government auction demanded it, solar panels could be customized for their environmental conditions in which they would be placed, ie, extreme heat panels, extreme wind panels, high humidity panels. Right now, panels are one single flavor, when it is possible they could be designed not only for better efficiencies, but also for significantly longer longevity.

        • Actually the Chinese are building around 18 nuclear plants, domestically, at a median build time of 5.7 years. Predominately they are a French and USA designs. Also the odd few in other countries like the UK. My beautiful PV panels suffer downtime every day. Some days, all day.

          • dumboldguy Says:

            Shush! No fake news about nukes allowed here in the land of the nuke-haters!. Better that you should talk about some of the real science that nuke-haters also subscribe to, like how bad vaccines and GMO’s are.

          • Gingerbaker Says:

            “Actually the Chinese are building around 18 nuclear plants…”

            Here is the problem – how do you count them? Because you can’t count nuclear plants if they are just “planned, you can’t count them if they are just “approved”, you can’t even count them if they are just “under construction”, either, as they are abandoned all the time.

            Like this 25 billion dollar boondoggle in Georgia:

            China is building only five nuclear plants at present, and experiencing delay with them and the next wave due to start construction appears to have been delayed. And this is in China, where economics play little role:


            Indeed, nuclear is becoming restricted more and more to countries run by oligarchs, like Russian satellites. Because it is too damned expensive to compete in the capitalistic world.

          • Gingerperson, a mere glance at your link shows 5 nuclear plants coming online in 2018, not just 5 being built. Tsk tsk. Why are these disputes even happening? Action needs to be, must, start as soon as possible. This is self evident and will be crapee expensive regardless. Future tech and ideas, whether fantastical or practical, do not count until they (if) work, are built and contributing in a meaningful way. Total renewable’s is wishful thinking at present technology, and need turn key backup. Got a better one than nuclear, go for it. All should keep the eye on the goal and maintain THAT goal.

          • Brent Jensen-Schmidt Says:

            Gingerperson. This panti spat began with the statement ‘nobody is building nuclear plants’. Incorrect, and so they have problems Sherlock. So do Mekong hydro dams, horrors to betsy. Build all solar plants, wind farms and anything that works, great! Standing against a solution based on dogma, and it is unscientific dogma, is against saving the planet.

        • dumboldguy Says:

          “And colder weather increases those panels efficiency by the same amount”.

          Yeah, and colder weather usually occurs in the winter when days are shorter, tend to be cloudier, and snow falls, negating any gains in in efficiency.

          “I can propose cheap additions to solar panels to make up for the small losses during elevated heat”

          Yeah, adding more panels to a roof that is already covered with them is cheap and easy, as is air or water cooling, which would likely more than use up any additional electricity that is generated.

          Keep blathering on about solar and piling more dirt on the grave of nuclear power, GB. Don Quixote needs help.

        • jfon Says:

          ‘..colder weather increases those panels efficiency by the same amount. So, back to the stated overall output.’ Or it would be, if Stockholm, for example, didn’t average only an hour and a half of sunshine per day for the three months of winter, with snow on the panels for some of that time. Fact is, every year renewables boosters make a big deal of a few reactors closing for a week or two, ignoring the fact that solar fails every night and most of the winter, wind every time a high parks over the continent. It’s a ‘ man bites dog’ story – nuclear plants are so reliable, when they have to shut it makes the news. Solar and wind power-downs would only be noticeable if people had to rely on them – which nobody in his right mind does.

          • Gingerbaker Says:

            “Yeah, adding more panels to a roof that is already covered with them is cheap and easy, as is air or water cooling, which would likely more than use up any additional electricity that is generated.”

            Here you go again, making bad assumptions.

            First of all, not all PV goes on rooftops. You’ve heard of solar farms? They are on the ground, and cost 2 to 5 times *less* per watt output than rooftop solar? It’s easy, if you wanted, to add more panels. Not that you would need to – people already take temperature efficiency losses into account when they spec out the farms.

            But even if you are talking about rooftop, there exist, like I said before but you evidently missed it, or simply scoffed at it, options for cooling. Most don’t bother, of course, because it ain’t a big problem, but some opt for stuff like passive cooling using ridged sheets under the panels, internal fans, external fans. There are companies selling hybrid panels that incorporate water cooling which is harvested as thermal energy for hot water use.


          • dumboldguy Says:

            Again, your self-delusion is obvious. That “ground” you speak of as being under solar farms is NOT free, and the cooling “fixes” that some adopt are not free either. Of course, if your motto is “Damn the real facts about cost, full speed ahead”, you will keep waffling.

          • Gingerbaker Says:

            ” It’s a ‘ man bites dog’ story – nuclear plants are so reliable, when they have to shut it makes the news.”

            Your anti-solar and anti-wind slip is showing, and you are full of it re nuclear reliability – it has unscheduled downtimes just like everything else. Sure, the industry and its boosters like to quote a 96 percent capacity factor… but that ain’t the whole story

            Here is the real data, from the EIA:

          • dumboldguy Says:

            NINETY+ freaking percent isn’t the whole story? Nuclear isn’t at the top of that chart by a huge margin?

            “REAL data” is meaningless to those with cognitive dissonance, and yours re: solar/wind/nuclear borders on delusional.

          • Gingerbaker Says:

            Real data???

            That chart shows nuclear is often in the 70th percentile. Cognitive dissonance indeed.

          • Gingerbaker Says:

            “Gingerperson, a mere glance at your link shows 5 nuclear plants coming online in 2018, not just 5 being built. Tsk tsk. ”

            Until they are on-line, they are still being built. As in: not open for business. And you talked about 18, not 5, but neglected to give apologies for your over-estimation. The second article addresses the unknowns about those 13 additional plants and others.

            It even talks of Chinese nuclear plants completed and only needing fuel installed which are then put on “hold” status.

            Tsk tsk yourself.

          • Gingerbaker Says:

            “That “ground” you speak of as being under solar farms is NOT free, ”

            Who said “free”? Not me. You said it was not possible to have space to add panels to a roof. I pointed out panels also go on farms. Then you started talking about free land, for some unknown reason.

            Again temperature efficiency calculations are part of the planning process. But adding more cooling towers to a nuke plant – nope.

            Tell us, Mr “Nuclear is not dead” – how many new nuclear plants are being planned in the U.S.?

  2. These nuclear plants need more efficient ways of using their coolwater. Dumping the warm water in to rivers is a wast. There must be better ways to use this warm water.

    • jfon Says:

      In some cases, reactor waste heat is used for district heating in winter. This should be done more often, replacing the coal-powered district heating in places like Denmark and China. Not much you can do with it in summer, though. Newer reactor types, cooled by molten salt or metal, or helium, would run about 200 C hotter than current light-water reactors. This would raise their thermal efficiency from ~35% to over 45%, with a concomitant reduction in water use for the same power. ( Skating rinks sometimes use their cooling waste heat for an adjacent swimming pool’s heating, but it doesn’t work the other way. Entropy rules.)

      • Andy Lee Robinson Says:

        Warm waste water could be stored in vast underground tanks for use in the winter in conjunction with heat pumps to amplify the temperature.

        It’s scandalous that so much of the energy used to heat steam to drive turbines and then condense it is just wasted when it could be stored or used for district heating instead of being dumped unsold into the environment.

        • dumboldguy Says:

          YES! That’s a far better alternative to storing the waste heat in the ocean and atmosphere as we are now doing. It is so danged hard to get it back when you need it and it tends to pop out as heat waves when you don’t need it or want it

        • jfon Says:

          The laws of entropy – you can’t win; you can’t even break even ; you can’t quit. If you’re using energy, you’ll be losing heat.

  3. Gingerbaker Says:

    “Yeah, and colder weather usually occurs in the winter when days are shorter, tend to be cloudier, and snow falls, negating any gains in in efficiency.”

    See, now you are just talking out of your butt. Not a good orifice to speak from.

    Solar PV panels rated output is measured at 25C = 77 degrees Fahrenheit. The efficiency of panels increases below that temperature, and decreases above that temperature by the same factor. That factor is different for all the different panel designs, but ranges from as little 0.1x to as much as 0.50.

    So, that increase in efficiency happens not just during winter, but during all seasons. Most of the time, the decrease in efficiency is pretty darned small:

    Different panel types are used for home rooftop vs larger-scale solar farms, and the farm types can be less affected by this phenomenon, but here are some facts and figures for rooftop panels. The usual high panel temperature is pegged at 45C, which would result in a 10 percent reduction:


    • dumboldguy Says:

      I’M the one who’s talking out of my butt? LOL

      You are fixated on trying to make solar look good under any conditions. I will say again—-cold = winter = lower temps AND shorter days (less sunlight) AND more clouds ( less sunlight) AND snow on the panels (less sunlight) = less power (sometimes very little). Do you ever REALLY read others’ comments before giving us the “cult chant”

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