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Earth Science

Norwegian Town Using Sun-Tracking Mirrors To Light Up Dark Winter Days 143

Posted by samzenpus
from the light-up-my-life dept.
oritonic1 writes "During their long, cold winters, the Norwegian town of Rjukan doesn't enjoy much by way of daylight—so the town (population 3,386), installed three giant sun-tracking mirrors to shine a steady light over a 2000 square foot circle of the town square. From Popular Mechanics: 'Call it a mood enhancer. Or a tourist attraction. But the mirrors, which will be carried in via helicopter, will provide an oasis of light in an otherwise bleak location at the center of the 3500-population town. Three mirrors with a total surface area of about 538 square feet will sit at an angle to redirect winter sun down into the town, lighting up over 2150 square feet of concentrated space in the town square. A similar idea exists in the Italian village of Viganella, which has used brushed steel to reflect light since 2006.'"
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Norwegian Town Using Sun-Tracking Mirrors To Light Up Dark Winter Days

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  • by Chrisq (894406) on Thursday July 25, 2013 @04:43AM (#44378957)
    It didn't work out well in Lord Parker's 'Oliday [wikia.com].
  • by bogaboga (793279) on Thursday July 25, 2013 @04:43AM (#44378959)

    ...I live along the equator where our days and nights ar "equal" throughout the year.

    Trouble is that most Europeans I have met on my travels think it's hot hot hot at the equator, which isn't the case. In fact, their summers, which are responsible for some deaths among the elderly and young ones, are way hotter than the hottest day at home.

    When I say this, they won't believe it until I remind them that we are at a higher elevation which is cooler...just like the clouds.

    • by Pascal Sartoretti (454385) on Thursday July 25, 2013 @04:52AM (#44379007)

      ...I live along the equator where our days and nights ar "equal" throughout the year.

      I am glad to live in a place (Central Europe) where there are seasons, and not the same thing all over the year.

      • by Jah-Wren Ryel (80510) on Thursday July 25, 2013 @05:49AM (#44379171)

        I am glad to live in a place (Central Europe) where there are seasons, and not the same thing all over the year.

        As someone who spent the first 20 years of his life in an area without significant seasonal changes and the next 20 years in areas with major seasonal changes I can definitely say that seasons are vastly overrated.

        Having near perfect weather every day is about the least horrible curse I can think of.

        • by Arrepiadd (688829) on Thursday July 25, 2013 @06:14AM (#44379257)

          As someone who spent the first 20 years of his life in an area without significant seasonal changes and the next 20 years in areas with major seasonal changes I can definitely say that seasons are vastly overrated.

          Having near perfect weather every day is about the least horrible curse I can think of.

          Except that being next to equator does not guarantee "near perfect weather". Plenty of friends from places close to equator just say "back home we carried an umbrella every day even if it only rained once a week, because when it did it was pouring really hard.

          And to further counter your example, the more artistic oriented among those friends, even after years of being in a place with significant seasonal changes really appreciate contrast of green summer bursting with activity and people vs the white winter of cold and quiet. Different people for different things, I guess.

          • by jittles (1613415) on Thursday July 25, 2013 @08:19AM (#44380003)

            As someone who spent the first 20 years of his life in an area without significant seasonal changes and the next 20 years in areas with major seasonal changes I can definitely say that seasons are vastly overrated.

            Having near perfect weather every day is about the least horrible curse I can think of.

            Except that being next to equator does not guarantee "near perfect weather". Plenty of friends from places close to equator just say "back home we carried an umbrella every day even if it only rained once a week, because when it did it was pouring really hard.

            Huh. I didn't know people in tropical areas bothered with umbrellas. I lived about 10 degrees north of the equator for a year. Yeah it rained like hell, and an umbrella was useless. Either the rain would come in sideways, or come in so hard and so fast you had to worry more about the water coming up than the water going down. I've seen rocks about half the size of a bowling ball being carried down the gutters along with lawn chairs and everything else you can imagine during an especially strong rain. But contrary to popular belief, most tropical areas do have two seasons: the wet season and the dry season. Where I lived, it rained almost every day for hours on end during the wet season. During the dry season, it may rain for 10 minutes each day, or may not rain for several days.

            • Where I live we have four seasons. The long dry, the long wet, the short dry, and the short wet.

              And as stated by others, the weather is really nice. Actually, at the moment it's a bit cool, sometimes it goes as low as 21 degrees! It does get a little hot sometimes (up to 35 degrees), but just don't go outside.

              And, we use an aircon at most one month a year when it does get really hot. Where I lived previously it used to get into the 40s for two or three months a year. And then bloody cold in the winter. Who

        • Re: (Score:3, Informative)

          by txibi (1691198)

          Having near perfect weather every day is about the least horrible curse I can think of.

          It depends on what you understand by nearly perfect weather. The nearly perfect weather to practice ski is not the same one that you need for swimming in the sea... For this I like having seasons on where I live and being able to practice different sports depending on the season.

          • by SuricouRaven (1897204) on Thursday July 25, 2013 @07:18AM (#44379555)

            Consistancy is key.

            Here in the southern UK, it snows sometimes. Not a lot. Maybe for a week, no more, and only every two years - often we go a winter with no snow at all, or just a very light dusting.

            When it does snow, everything stops. Roads are impassible, schools close, almost total shutdown of the country. Why? Because we don't keep an army of ploughs and gritters and a big stockpile of salt around for something that happens so rarely and is over so quickly.

            Likewise with very hot summers. The crushing heat can reach thirty celcius. In somewhere like the southern US they'd laugh at that - but in those places, everyone is used to it, with buildings made to stay cool and every home fitted with air-con. We melt for about a week a year, so we just endure - the awkwardness is over too soon to justify building houses that stay cool (And thus cost a lot more to heat in winter) or installing expensive aircon systems.

            • by dj245 (732906) on Thursday July 25, 2013 @08:04AM (#44379871) Homepage

              We melt for about a week a year, so we just endure - the awkwardness is over too soon to justify building houses that stay cool (And thus cost a lot more to heat in winter) .....

              Buildings that stay cool in summer and are warm in winter are not mutually exclusive. Presenting them as conflicting design goals is silly considering that these design goals are often complementary.

              • by T Murphy (1054674)
                That depends... if your house has a furnace and an air conditioning unit, your main concerns are having a well insulated house, and having some means of reducing the impact of solar heat load (the sun generally hurts more in the summer that it helps in the winter). If you have heating and no air conditioning, you'll have a warm house in the winter, but your house might not cool down very well in the evenings during the summer.
            • by jbengt (874751) on Thursday July 25, 2013 @08:23AM (#44380035)

              The crushing heat can reach thirty celcius. In somewhere like the southern US they'd laugh at that

              30C (86F) is stifling heat? We laugh at that in the Northern US. True, it would be a little uncomfortable indoors without A/C or at least good ventilation, but you would have to start talking at least 35C or maybe 40C before making US southerners uncomfortable outside. (OK, you'd have to talk 95F to 104F, since they would mostly just look at you funny and wonder what planet you're from if you talk Celsius.)

              • by Luckyo (1726890) on Thursday July 25, 2013 @09:24AM (#44380729)

                Here in Finland, official "hot" figure for weather is at 27C. And yes, when it's 27C, it's exhausting hot.

                On the other hand, -27C is nice weather to go out and ski/skate. And most buildings do not have A/C because there's no real reason to - the season during which you would need it lasts days if it ever comes at all.

              • by tlhIngan (30335)

                30C (86F) is stifling heat? We laugh at that in the Northern US. True, it would be a little uncomfortable indoors without A/C or at least good ventilation, but you would have to start talking at least 35C or maybe 40C before making US southerners uncomfortable outside. (OK, you'd have to talk 95F to 104F, since they would mostly just look at you funny and wonder what planet you're from if you talk Celsius.)

                Depends on the location and average temperatures - take that same southerner and put them on the US-Ca

              • True, it would be a little uncomfortable indoors without A/C or at least good ventilation, but you would have to start talking at least 35C or maybe 40C before making US southerners uncomfortable outside.

                That's not necessarily true. Almost all homes and apartments in the South are air conditioned unless you're very poor. That kind of spoils us when it comes to high heat, as I learned when I moved for a few years out to the Pacific Northwest where they don't bother with A/C because it's only really needed in August.

                Maybe it's different if you're an outdoors type, but for most of us 40 C is "stay the f--- indoors" weather, especially when humidity is as high as it is in most of the South.

              • by GodGell (897123)

                The crushing heat can reach thirty celcius. In somewhere like the southern US they'd laugh at that

                30C (86F) is stifling heat? We laugh at that in the Northern US. True, it would be a little uncomfortable indoors without A/C or at least good ventilation, but you would have to start talking at least 35C or maybe 40C before making US southerners uncomfortable outside.

                That's quite "moderate" by mainland European standards, too: I'm sitting in 34C indoors at the moment (Central Europe), and it's almost 40 outside (93F/104F). I've had hotter summers, too, but only in the last couple of years; I don't know what it's like elsewhere, but I distinctly remember the weather being completely different (more predictable, less extreme) as I was growing up...

                PS. Kudos for being the first American I've seen on Slashdot who recognizes noone else uses F. :-)
                As an aside - seeing as this

      • by RivenAleem (1590553) on Thursday July 25, 2013 @05:52AM (#44379181)

        As someone living in Ireland, I can tell you the lack of seasons isn't restricted to the equatorial areas.

      • by Anonymous Coward

        I am glad I am not a foreigner, too. No one likes foreigners!

    • Re: (Score:2, Informative)

      by Anonymous Coward

      Rjukan isn't all that far to the North, but it's located in a deep valley, with mountains on every side. When the sun gets low in the Winter, the town is in constant shade.

      • by dkf (304284)

        Rjukan isn't all that far to the North

        While it's not that far north for Norway (where it's in the south of the country), it's still nearly 60N. In any reasonable terms, that's still a long way north; you have to go pretty much to the Antarctic peninsula to get an equivalent distance south. Heck, the axial diameter that far north is only half that of the equator...

    • by h3st (945000)
      The problem with Rjukan isn't so much the seasons as the fact that it's in the bottom of a steep valley. So part of the day the sun is shining on one mountainside, then a short period where sunshine reaches the town, and then the other mountainside gets sun. Having a similar town near the equator could be better or worse, depending on the axis of the valley.
    • until Climate Change is finished. Then we can talk about where is a nice place to live or not. My area promises to be much nicer in the future with less seasonal change than now. I'm looking forward to change.
    • by gstoddart (321705)

      When I say this, they won't believe it until I remind them that we are at a higher elevation which is cooler

      Then I assume what you're describing is purely a result of altitude, no?

      I should think anywhere which is equatorial and at sea level is going to be hella hot year round ... then again, I've never been south of about 23 degrees North, so I have no idea.

      • Then I assume what you're describing is purely a result of altitude, no?

        I should think anywhere which is equatorial and at sea level is going to be hella hot year round ... then again, I've never been south of about 23 degrees North, so I have no idea.

        Yes, very likely. I lived in Ecuador for about a year, at 3800m altitude, where the temperature averaged something like 10C all year. A 45 minute (very entertaining) ride by motorcycle, however, took you down to about 1800m and ~28C. Another hour and you were at the coast, which was hellish at 35-40C.

  • by Anonymous Coward

    The exact opposite or Mr. Burns?

  • "It occurred to me that you wouldn't live near perpetual darkness, if you people would MOVE WHERE THE SUN SHINE IS!!!"
  • by Pascal Sartoretti (454385) on Thursday July 25, 2013 @04:57AM (#44379025)

    ... a 2000 square foot circle of the town square ... ... about 538 square feet ... up over 2150 square fee

    This is slashdot science ?

    Besides, the slashdot summary is ambigous : it mentions a population of 3,386, but in which unit ? Number of legs ?

    • by wonkey_monkey (2592601) on Thursday July 25, 2013 @05:09AM (#44379071) Homepage

      Number of legs?

      No, number of feet, of course.

    • by Kidbro (80868)

      While I agree that it's a stupid unit, ft2 to m2 conversion is really easy. Divide by ten, and you have a good approximate. Lean towards rounding down, if unsure.
      1 square meter is 10.7639 square feet.

    • Re: (Score:2, Insightful)

      by PPalmgren (1009823)

      A scientist or engineer that can't handle common unit conversions is an unemployed scientist or engineer.

      The article is from a US website intended for a US audience, and uses US measurements. I don't expect a news aggregator to do extra work because you're lazy.

    • by kermidge (2221646)

      What's tough about it? Far as I can tell, the submitter was going with what info was presented in the article. Perhaps due diligence would have required him to call the town mayor and ask for precise numbers?

      One sentence says it lights up a circle of about 2000 sq. ft.
      In another sentence, the mirrors total 538 sq. ft.
      Onward, a more precise figure is given for the area of the circle, 2150 sq. ft. (From the middle slide, it's more like an ellipse, but that's kinda irrelevant; what matters, I think, is that

  • Why not a ballon, of the size of a giant hat, make of a tinfoil? If would need to be tilted somewhat, and turn itself towards the sun -- easy in the case of a ballon. Would not it be much cheaper? Of course, tinfoil does not have the directionality of a glass mirror, but make the hat big enough and it would not be a problem, and even be a feature -- the more ambient light would not decrease the iris size so much, and thus a human would perceive the lighted area as even more bright.
    • by Sique (173459)
      Because a balloon would not direct much of the light into the town, but basicly everywhere. Sun light is (nearly) parallel, and to reflect it into a town, you need a plane reflector. Only a small part of the balloon's surface would reflect the light into the desired direction.
    • by art6217 (757847)
      It had to be "the shape of a hat" -- i. e. with a flat mirroring surface on the bottom side, and with a gas container on the top side.
  • Couldn't the same setup be used to make steam that could make electric? I think i seen an article of something simuler. Cant remember where/when. Couldn't magnifying glasses do the same also focus light to create steam?
    • by Ogive17 (691899)
      It's not a village living in the stone age, they just lack natural sunlight.
    • by geirlk (171706)

      Probably they could, yes, but would provide low return on investment. And since Rjukan was more or less built to size to man the hydro electric dam that feeds the entire area and earlier also powered Vemork factory, that would seem a bit superfluous. Besides you'd need a lot more mirrors than that.

      • by geirlk (171706) on Thursday July 25, 2013 @09:55AM (#44381131)

        http://www.imdb.com/title/tt0059263/ [imdb.com]
        http://en.wikipedia.org/wiki/Vemork [wikipedia.org]

        Some trivia:

        The Vemork factory was placed exactly there because of the optimal conditions for producing hydroelectric power.

        It started out fixing nitrogen for fertilizer, but later on was converted to produce heavy water. This is what Hitler needed for the production of a nazi A-bomb.

        Both nitrogen fixing and production of heavy water is extremely power consuming.

        The factory (and Rjukan city itself) lies so deep within the valley, the Allies considered it near impossible to bomb. They tried, once. The production was considered so important the Allies tried 4 sabotage operations against it.The most famous one, Operation Gunnerside, was made as a film, starring Kirk Douglas: The Heroes of Telemark.

        PS: Sorry about the links on top, using a shitty mobile browser.

  • They make electric 'day' lights you know. Ever been to a sports arena? If they can light an entire football pitch, why not just do this the old fashioned, non-expensive, non-boondogle way? Buy some floodlights and be done with it.

    • by Trepidity (597)

      Tourism's an important part of the local economy, so this could end up a decent gimmick from that perspective. Giant sun-tracking mirrors sounds like a more interesting tourist attraction than stadium-style floodlights.

      • by CastrTroy (595695)
        I never really understood why small towns did this stuff in the name of "tourism". Yeah, nobody wanted to visit your town before, but you built a big sun reflector, or a statue of some famous dude, and now you think it's a tourist destination. You know what kinds of things are actually tourist attractions? Disney world, The Grand Canyon, The CN Tower, and other stuff like that. Why would you go to some valley town where they have to reflect the sun so you can get sunlight when you can travel an equal dis
        • What part of "Tourism's an important part of the local economy" was so difficult to understand?

          That being the case, people are already visiting the town. In fact, if you could have been bothered to just search some info about this particular town, you'd know that the tourists visited that area for a few centuries, actually before the town even existed, because of the beautiful nature. Besides, the town belongs to the Telemark community, and Telemark basically stands for winter sports.

        • by geirlk (171706)

          http://en.wikipedia.org/wiki/Vemork [wikipedia.org]

          That could be one reason.

    • by Anonymous Coward

      It's Norway. 98% of their power is hydroelectric so they don't really need to reduce energy consumption for economic/environmental reasons. They are also in the top 5 of highest oil production per capita so they pretty much have more money than they know what to do with.
      Without energy and economy being limiting factors it just becomes a matter of life quality.

      They don't care about the light, they want some fancy natural sunlight and this option was easier than removing the mountain.

    • by necro81 (917438) on Thursday July 25, 2013 @07:39AM (#44379691) Journal

      why not just do this the old fashioned, non-expensive, non-boondogle way

      The article states that the project cost is only about $850k, mostly provided by private donations. The tracking motors will be solar-powered. So, for a modest outlay of capital today, they get ample, high-quality, non-polluting light for next to nothing for the life of the system. Any idea what a stadium lighting system costs? How about the cost of electricity and replacement bulbs to keep it operating for 8-16 hours a day, five months out of the year, for decades? Mirrors on a heliostat is not a boondogle, it's proven technology. And, in this case, probably cheaper than the alternative.

      • that money could have bought dozens of street lamps and paid the electric bill for years

        • by rasmusbr (2186518)

          Yeah, the cost of the electricity would have been an order of magnitude lower than the cost of the mirror system if we assume that it consumes 10 kW and runs for 10 hours a day 200 days a year. It would also probably have been more reliable and easier to service...

          But on the other hand, would the electric light be able to simulate the spectrum of natural light the way that natural light changes during the day? Would the electric light double as a minor tourist attraction the way that the mirror probably wil

  • by Tore S B (711705) on Thursday July 25, 2013 @06:20AM (#44379275) Homepage

    Rjukan is also the site of the museum of industrial labour, which is located in Vemork. In addition to being a very early heavy water plant which was sabotaged by the Resistance during the second world war to hinder the Nazi nuclear bomb project, it also currently hosts an exhibit of what is probably the world's only remaining Univac 1108 mainframe.

  • Ok so who's going to be the person to set up giant magnifying classes in front of the mirrors?
  • Several stationary mirrors-walls with different angles, using pieces of broken mirrors placed into the cement. Sort of mirror mosaic.

    Could be built by inhabitants themselves. No need for a million dollars or electricity.
    • by Max_W (812974)
      Or a very large discotheque mirror ball on the mountain.
    • by jittles (1613415)

      Several stationary mirrors-walls with different angles, using pieces of broken mirrors placed into the cement. Sort of mirror mosaic.

      This may not work though, depending on how much snowfall they get. Mirrors that track the sun could be designed to dump snow, and since they track the sun are more likely to have any snow covering the mirrors melt. I haven't looked at the weather specifics of this town, but there are advantages to moving mirrors. Now if snow were to build up under the mirrors, they would not be able to move anyway, so there are plenty of issues to worry about.

  • by methano (519830) on Thursday July 25, 2013 @06:47AM (#44379399)
    They did this same kind of mirror thing in Rattenberg, Austria a few years back.
  • Here's the location on google map : https://maps.google.com/maps?q=59.878637,+8.594049&hl=en&ll=59.878795,8.594055&spn=0.009131,0.02959&sll=37.0625,-95.677068&sspn=60.116586,121.201172&t=h&z=16

    Look at the mountains on both side of the main street with street view, one is blocking the sun in winter and the other is certainly where the mirrors will be.

  • by LoRdTAW (99712) on Thursday July 25, 2013 @07:30AM (#44379621)

    Now we could hack into the controller and reprogram it to direct the sun to a single point and voila! Instant death ray. Might help with the tourist problem.

  • by hawguy (1600213) on Thursday July 25, 2013 @07:37AM (#44379677)

    How does this mirror compare to installing full spectrum lamps to light up the same 2000 sq ft area? Lights could provide extended "days" during the winter months, and could be solar powered from the same mountaintop that houses the mirrors when the sun is out.

  • Really, a town named Viganella with mirrors all over the place? These jokes write themselves!
  • If the mountain is a 2km away the reflection from the mirror is going to be very broad indeed. The sun is a half-degree across, and half-degree times 2km means that the edges of the mirror beam will be about 20 meters wide, nice soft edges and not the harsh ellipse shown. The ends of the ellipse will have edges more like 100 meters wide.

  • Was this plan conceived by an eight year old boy?

    There are millions of ants screaming "Never Again!"

  • ... who thought, after reading the title, that they were going to put mirrors into space? Giant mirrors in geostationary orbit focussing the light onto a small Norwegian town? Now that would be a tourist attraction.

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