Slashdot Mirror


South Africans Revolutionize Concentrated Solar Power With Mini Heliostats

Taffykay writes: Concentrated Solar Power (CSP) offers significant benefits, but it's often prohibitively expensive. Paul Gauché from Stellenbosch University in South Africa hopes to change that with Helio 100, a series of 'plonkable' miniature heliostats that require no installation or concrete, and offer solar energy that's cheaper than diesel. The Guardian reports: "Helio100 is a pilot project with over 100 heliostats of 2.2 sq meters each, generating 150 Kilowatts (kW) of power in total – enough to power about 10 households. According to Gauché, the array is already cheaper than using diesel, the go-to fuel for most companies and businesses during regular power outages in the country.

106 comments

  1. ain't no sunshine when she's gone by turkeydance · · Score: 3, Funny

    and i know, i know , i know....

  2. Last sentence makes me squirm with anticip- by ClickOnThis · · Score: 2

    ...

    So, what is Google's RE?

    --
    If it weren't for deadlines, nothing would be late.
    1. Re:Last sentence makes me squirm with anticip- by Anonymous Coward · · Score: 0

      If only there were some amazing internet search technology where you could cut and paste Google's RE and get an accurate answer.

    2. Re:Last sentence makes me squirm with anticip- by ClickOnThis · · Score: 4, Informative

      If only there were some amazing internet search technology where you could cut and paste Google's RE and get an accurate answer.

      Yeah...maybe Google could even offer it. Oh, wait.

      And now the penny drops: it's a broken reference to Google's RE<C.

      Thanks for the improvement.

      --
      If it weren't for deadlines, nothing would be late.
    3. Re:Last sentence makes me squirm with anticip- by alvinrod · · Score: 1

      For me, I have no idea. Maybe something about a renewable energy program from Google assuming it's some kind initialism.

      For samzenpus, par for the course.

    4. Re:Last sentence makes me squirm with anticip- by Anonymous Coward · · Score: 0

      Might've been HTML kicking in. Still on him, though.
      -AC.Falos

    5. Re:Last sentence makes me squirm with anticip- by Anonymous Coward · · Score: 0

      Yeah, what a lazy git, in fact the summary should just be a series of 5-7 keywords for you to put into Google instead of bothering with all this longwinded single paragraph crap.

  3. Another deflationary pressure on oil prices. by Maxo-Texas · · Score: 3, Insightful

    Imagine if these cut diesel fuel usage in africa by 30% over the next 5 years.

    --
    She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
    1. Re:Another deflationary pressure on oil prices. by ihtoit · · Score: 1

      I dunno, is the roof of a tractor trailer big enough to hold a thirty by seventy foot solar array? I can see it working for houses, ten joined terraces has got to be larger than that in roof area, even flat roofs (I'm going by my shoebox which is typically sized for a 1960s midterrace town house in England, at 70 feet deep and twelve wide including the garage - with that kind of efficiency you'd only need to cover 30% of existing roofs to meet the entire domestic power demand), but then you've got infrastructure to deal with as well: converters, storage, isolators...

      --
      Political debates have me rolling my eyes so much I think I got optical whiplash. I should sue. - Foamy The Squirrel
    2. Re:Another deflationary pressure on oil prices. by cloud.pt · · Score: 1

      That's gonna need the help of another South African, you know, the one who makes the batteries that can store the electricity so it can be used in and by moving objects? Model T coming up in 5... 4...

    3. Re:Another deflationary pressure on oil prices. by Darinbob · · Score: 2

      In some places, more diesel is used for electricity than is used for vehicles.

    4. Re:Another deflationary pressure on oil prices. by Maxo-Texas · · Score: 1

      Of just use solar when it's day and not raining. Otherwise use diesel as normal. If you are wise, take a portion of the savings and funnel it into batteries.

      --
      She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
    5. Re:Another deflationary pressure on oil prices. by dbIII · · Score: 1

      Less consumption makes supply easier.
      This is a situation where consumption is low so roof space is not an issue - plus the cost of covering the roof space is far more and issue than available space.

    6. Re:Another deflationary pressure on oil prices. by DarenN · · Score: 1

      Like, for instance, in South Africa, where electricity delivery is very unreliable and most businesses have diesel generators as backups. This also goes for large portions of the continent where power delivery is very unreliable for a host of reasons. (this was aimed at the GP, in case anyone's wondering.)

      --
      Rational thought is the only true freedom
    7. Re:Another deflationary pressure on oil prices. by Anonymous Coward · · Score: 0

      which implies don't use solar power in the UK at all

  4. No details by Michael+Woodhams · · Score: 4, Informative

    TFA is lacking in details about how this works, but if you follow the link you get to a Guardian article which is lacking in details, but links to the projects website which excessively uses gratuitous Javascript and is lacking in details.

    They talk about "plonkability" - that the mirror structures can just be plonked on the ground and will 'just work'. This suggests to me that somewhere in their system is some intelligence or calibration which is able to notice where each mirror is relative to the target and adapt its pointing accordingly. Their photos show the target tower having two rectangular surfaces pointed towards the mirrors. I suspect the plane white surface is there to aid mirror pointing calibration in some way, but I don't know.

    --
    Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
    1. Re:No details by tsotha · · Score: 1

      I've always wondered if this could be done with GPS. If you know where you are and where the tower is, you can figure out what angle the mirror should be to point at the tower. That would get you close enough for some kind of autocalibration if you put the right kind of sensors on the tower and had a link to the mirror controller.

    2. Re:No details by Michael+Woodhams · · Score: 2

      You'd use differential GPS. Wikipedia says this has accuracy of 10cm in the best case. Whether that is good enough for this application I'm not sure. Given that affordability is a big part of their goal, if they were taking this approach they'd not attach a GPS to each mirror, but rather have two receivers that they used for a callibration stage and then wouldn't be needed again unless something shifted. You'd need to know orientation as well as location for the mirrors.

      I doubt this is what they're doing, but who knows.

      --
      Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
    3. Re:No details by AmiMoJo · · Score: 1

      There are low cost passive systems for angling solar panels towards the sun. Perhaps this is a development of that. They rely on heat causing expansion for automatic alignment.

      --
      const int one = 65536; (Silvermoon, Texture.cs)
      SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
    4. Re:No details by Anonymous Coward · · Score: 0

      If you check your Scientific Americans circa 1991, you'll find an article about "Non-Imaging Optics", which has many described applications, but is so tied up by Patents by Roland Winston, that nobody bothers with it any longer, other than Neutrino Hounds.
      In Solar Applications, "Non-Imaging Optics" captures all available Photons and directs them to a Line or Disc Receptor, over a wide acceptance angle, without little need for tracking.
      Small test stands have vaporized Tungsten Targets.
      It turns out that it doesn't work very well with uncooled Photovoltaics, but it's just dandy for Solar Thermal. A test at LBL used NIO to cool a small Computer Center. A letter from a Lawyer ended that experiment. All equipment was supposed to be destroyed, but...hehe...

      I feel that a little Intellectual Property Piracy is called for here. Winston is around 80 now; what's he going to do, gum you into submission?

      Captcha: subvert

    5. Re:No details by NakNak · · Score: 1

      More detail at the (South African) Mail & Guardian, published a couple of days before that Guardian piece, which confirms the intelligence is built into each unit.

      "The heliostats are effectively smart robots that 'know the angle between the sun and the tower, depending on the time of day, and know where the sun is with respect to the tower. They each know this independently'".

    6. Re:No details by Michael+Woodhams · · Score: 1

      Thanks, that is hugely more informative. A big bit of information is that they are using molten salt thermal storage.

      --
      Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
    7. Re:No details by Anonymous Coward · · Score: 0

      Small test stands have vaporized Tungsten Targets.

      Purely passive systems cannot produce temperatures with sunlight higher than the surface of the sun... which means they can't vaporize tungsten.

    8. Re:No details by tsotha · · Score: 1

      I don't see how you get from there to pointing at a specific spot. What angle the mirror needs to be relative to the sun is going to depend on exactly where it is relative to the tower.

  5. Bullshit by ChrisMaple · · Score: 3, Informative

    100 units of 2.2 sq meter each has a total solar input of 220 kW peak, roughly. They're claiming 150 kW. That's 68% efficiency, which nobody has achieved.

    --
    Contribute to civilization: ari.aynrand.org/donate
    1. Re:Bullshit by BoRegardless · · Score: 1

      Absolutely no data in the original article.

    2. Re:Bullshit by thinkwaitfast · · Score: 1

      Who, other than NASA, cares about efficiency, when you can buy panels for $0.28/watt?

    3. Re:Bullshit by Anonymous Coward · · Score: 0

      This isn't solar PV, this is solar thermal, and what they are claiming is better than any other solar thermal plant has ever demonstrated.

    4. Re:Bullshit by Michael+Woodhams · · Score: 1

      It isn't clear to me whether they collect heat and use some heat engine, or whether they use a small area of high cost high efficiency high temperature photovoltaic cells. As I've complained elsewhere, the articles provide almost no detail. There is mention of cooling water, but either possibility could use that.

      --
      Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
    5. Re:Bullshit by tlhIngan · · Score: 5, Informative

      That's 68% efficiency, which nobody has achieved.

      These are heliostats, not PV panels. Heliostats work by heating a salt to high temperatures then using the heat to power a turbine in a traditional heat engine. The latter tends to be highly efficient (over 90%), while the former is around 75% efficient or more.

      It is as the article says - it's converted to heat then heat is used to generate electricity, something a lot of power plants do (including nuclear, coal, natural gas, and others).

      If it was PV panels, you're correct, since the best PVs are only getting around 20%. But if you don't mind the extra space for the equipment, solar thermal is the way to go.

    6. Re:Bullshit by Khyber · · Score: 0

      Learn to read moron, OVER 100.

      Oh, and back to fucking school, because concentrated solar is WAY more efficient than PV.

      --
      Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
    7. Re:Bullshit by thegarbz · · Score: 0

      Powerplants benefit from economies of scale. They are talking about a system 2.2sqm in size. I'm sceptical.

    8. Re:Bullshit by Anonymous Coward · · Score: 0

      "Inhabitat" is the place to be for credulous, science-illiterate eco-enthusiasts.

      http://inhabitat.com/zero-energy-bio-refrigerator-cools-your-food-with-future-gel/

      "Probably the best thing about this concept machine is that it uses zero energy for cooling — it just needs energy for it’s little control pad. Compared to the typical modern fridge, which uses about 8% of a household’s energy, this nifty-looking gadget of the future could cut our energy use significantly."

    9. Re:Bullshit by superposed · · Score: 3, Insightful

      Heliostats work by heating a salt to high temperatures then using the heat to power a turbine in a traditional heat engine. The latter tends to be highly efficient (over 90%), while the former is around 75% efficient or more.

      I think you're trying to say that mirrors can heat salt with >75% efficiency and heat engines tend to be >90% efficient. The first claim seems vaguely plausible, but the second claim is certainly false. Typical single-cycle power plants have efficiencies around 35%, and combined cycle plants (combustion turbine plus heat-recovery steam generator) have efficiencies up to about 50%.

      With a heat engine operating at normal terrestrial temperatures (say 300 K on the cold side and 1000 K on the hot side), the maximum possible efficiency is 70%. To achieve 90% efficiency, the high temperature side would have to be at least 3000 K (half as hot as the sun). I doubt this system is that hot.

    10. Re:Bullshit by Anonymous Coward · · Score: 0

      The latter tends to be highly efficient (over 90%)

      You made that up.

    11. Re:Bullshit by DarenN · · Score: 1

      I'll buy one!

      --
      Rational thought is the only true freedom
    12. Re:Bullshit by Anonymous Coward · · Score: 0

      The latter tends to be highly efficient (over 90%)

      You made that up.

      Probably 90% of the theoretical possible maximum.

    13. Re:Bullshit by Anonymous Coward · · Score: 0

      My guess is lousy reporting. Try 150 kilowatt hours per day and see if that makes sense. I believe it does.

    14. Re:Bullshit by NakNak · · Score: 1

      But if you don't mind the extra space for the equipment, solar thermal is the way to go.

      Apparently so. There's a reference here to KaXu Solar One, 1km square made up of 120 parabolic troughs "delivering up to 100MW". And it seems that storage after sunset is baked in, with the promise that rocks will do it cheaper than molten salt.

    15. Re:Bullshit by K.+S.+Kyosuke · · Score: 1

      This isn't solar PV, this is solar thermal

      Well, maybe that's the first mistake right there. PV has surpassed CSP in economy a long time ago. That's why so many long-planned CSP projects have failed in recent years.

      --
      Ezekiel 23:20
    16. Re:Bullshit by Impy+the+Impiuos+Imp · · Score: 1

      100 of them, for 10 houses.

      --
      (-1: Post disagrees with my already-settled worldview) is not a valid mod option.
    17. Re:Bullshit by jimbolauski · · Score: 1

      Efficiency is important in any place where land is limited.

      --
      Knowledge = Power
      P= W/t
      t=Money
      Money = Work/Knowledge so the less you know the more you make
    18. Re:Bullshit by Coren22 · · Score: 1

      System? 2.2 Sqm is the size of individual mirrors in the system, not the whole system. There are 100 mirrors in the system (at least).

      --
      APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
    19. Re:Bullshit by Anonymous Coward · · Score: 0

      The turbines used in power plants are ~90% efficient. The whole power plant is around 35% once you take out the losses from combustion and cooling etc. I don't know for certain how efficiently the heat transfers from the salt to the drive fluid.

    20. Re:Bullshit by thegarbz · · Score: 1

      That makes more sense. The idea of it being "plonkable" was confusing. I interpreted this as a personal system, not part of a large system.

  6. Plonkable? by Anonymous Coward · · Score: 0

    Isn't that how one describes a hot chick?

  7. WTF by Anonymous Coward · · Score: 0

    I have a 5-ton central air unit, 2,600 square feet of house, a pool filter, all running a lot during the summer and I don't come anywhere close to needing 15kW worth of solar capacity. I need a little under 7kW to offset 100% of my PEAK use (about 6 kW to offset annual use). What the hell are they doing down in South Africa to use 250% more power per household?

    1. Re:WTF by thinkwaitfast · · Score: 1

      Nighttime storage maybe. That's what I do with my excess.

    2. Re:WTF by Chas · · Score: 1

      If it actually hits anywhere close to the target power? If, even on a somewhat cloudy day it achieves even 1/3rd to 1/2 that? Hell yeah!
      If you have the area to actually drop an array like this, you might actually be better off using this than a bank of solar panels.
      The only "downside" to the end user is that you'd probably need to increase the size/depth of your storage system. As you'd have less reason to economize during a power outage.

      It still has some issues with land use. But nowhere near as serious as the larger solar thermal facilities. And, given a large enough piece of property and the fact that the installation isn't fixed, could be rotated about the property periodically to minimize the impact even further.

      --


      Chas - The one, the only.
      THANK GOD!!!
  8. Correct spelling is Grauniad by Tokolosh · · Score: 1

    Ah, the smell of luvvies in the morning!

    --
    Prove anything by multiplying Huge Number times Tiny Number
  9. Useless link by Anonymous Coward · · Score: 0

    Why wouldn't you link directly to The Guardian (or, I'm sorry, "Gaurdian")? The intermediary page adds absolutely nothing, and garbles much.

  10. Re:Yet more vaporware by Anonymous Coward · · Score: 0

    hopes that their pilot project will be fully functional by October of this year

    Come back when it's *actually* generating electricity for 10 homes, and is cheaper than diesel.

    You forgot "more reliably than diesel or anything else that's more reliable than diesel" too.

  11. "Smokers" by Ungrounded+Lightning · · Score: 1, Interesting

    One problem with industrial-scale central-focus concentrating solar systems is "smokers" - birds that were fried by the concentrated light.

      - The concentrated light isn't visible as a bright spot in the air from below and the sides. It IS visible from above, as is the small percentage reflected from the object at the focus.
      - This light attracts insects.
      - The insects attract birds wishing to eat them
      - The birds fly into the focus.
      - The large amount of focussed sunlight kills them quickly and ignites them.
      - The birds fall out of the air, trailing a plume of smoke, and are known a "smokers" by people in the trade.

    Similarly with birds that see the object at the focus - typically the highest thing in the middle of a big flat region, and thus an especially attractive roosting place for predatory birds. - and decide to land on it..

    It's like the cruel kid with the magnifying glass frying ants - but written large.

    At 150 kW output (and substantially more input) it's not clear to me whether the birds would be instantly killed or merely blinded, badly burned, and left to suffer and die on the ground. But I bet even this village-scale heliostat system will suffer from this problem.

    --
    Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
    1. Re:"Smokers" by Socguy · · Score: 4, Interesting

      While what you talk about does happen, it's not a problem because of the relatively rare nature of the incidents. Skyscrapers in cities kill orders of magnitude more birds than power towers.

      Frankly, the birds would be far better off if we switched to CSP exclusively due to the wholesale destruction of habitat caused by fossil fuel development.

    2. Re:"Smokers" by Anonymous Coward · · Score: 2, Informative

      Bird deaths caused by wind and solar are minimal compared to the bird deaths caused by traditional fossil fueled infrastructure. Much like the wind turbine issue, it is much ado about nothing. It is just more visible and makes a better news story than the slow poisonings or secondary displacement deaths caused by other power sources, but in scale is far less damaging.

    3. Re:"Smokers" by Anonymous Coward · · Score: 1, Funny

      PERFECT, a solution to their chronic hunger problems in Africa...

    4. Re:"Smokers" by JoeMerchant · · Score: 2

      Nature of bird injury mostly depends on how the bird is exposed - full on strike, or did he just get "winged?"

      Maybe with large migratory populations, the carnage will continue for a long time. The elevated track people mover in Miami didn't run for a year or so after the tracks were built - pigeons thought the tracks were just the greatest place ever made to hang out, nest, etc. The first months of operation (of the very quiet electric cars) were a nasty pigeon bloodbath, feathers and guts everywhere. After a few months, the remaining pigeons caught on, there's hardly ever one run over anymore. I don't think any special mitigations (tiny cow-catchers, warning lights, sounds) were put in place, just Darwin in action.

    5. Re:"Smokers" by Ungrounded+Lightning · · Score: 1

      Bird deaths caused by wind and solar are minimal compared to the bird deaths caused by traditional fossil fueled infrastructure.

      Thanks.

      I was already aware that wind power, despite the "bird kill" hype, was not all that large a problem. (I'd also thought it might be overestimated, too: Birds die where they live, and wind farms are good hunting sites for raptors and feeding sites for other birds.) It's good to have references to studies actually comparing it to other sources of power - and the comparison to power TRANSMISSION is a really big deal - and might swamp any bird-death issues with heliostats.

      Unfortunately, that article seems to be addressing only wind power and not large central-focus collection systems.

      I'd be happy to see a study estimating the magnitude of the problem (and whether it IS a substantial problem), and will be overjoyed if the problem is trivial, or at least no more than on a par with "traditional" power sources.

      Meanwhile I just wanted to caution that there MAY BE a problem, which needs to be examined.

      --
      Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
    6. Re:"Smokers" by dbIII · · Score: 1

      Yep - just like the bird that hit a window, pretty tough for the bird.
      It doesn't stop us having windows so as a stalking horse for a politically motivated objection it's very weak.

      That politically motivated objection is making some people in China very rich on US developed technology that kept on getting knocked back.

    7. Re:"Smokers" by Anonymous Coward · · Score: 0

      Nature of bird injury mostly depends on how the bird is exposed - full on strike, or did he just get "winged?"

      Maybe with large migratory populations, the carnage will continue for a long time. The elevated track people mover in Miami didn't run for a year or so after the tracks were built - pigeons thought the tracks were just the greatest place ever made to hang out, nest, etc. The first months of operation (of the very quiet electric cars) were a nasty pigeon bloodbath, feathers and guts everywhere. After a few months, the remaining pigeons caught on, there's hardly ever one run over anymore. I don't think any special mitigations (tiny cow-catchers, warning lights, sounds) were put in place, just Darwin in action.

      "Darwin" operates a little slower than that. It was just simple learning.

      The one's that didn't learn, needless to say, got sacrificed to Darwin.

    8. Re:"Smokers" by Jack+Griffin · · Score: 1

      At 150 kW output (and substantially more input) it's not clear to me whether the birds would be instantly killed or merely blinded, badly burned, and left to suffer and die on the ground. But I bet even this village-scale heliostat system will suffer from this problem.

      Not sure about this installation, but one I read about in Australia was in the desert, where there are no birds.

    9. Re:"Smokers" by K.+S.+Kyosuke · · Score: 1

      Well, they do, but largely because there's so many more of them.

      --
      Ezekiel 23:20
    10. Re:"Smokers" by Anonymous Coward · · Score: 0

      Its too bad that life doesn't have some method of pruning poor performing adaptations and concentrating on better ones.

    11. Re:"Smokers" by LongearedBat · · Score: 1

      Gives new meaning to "smoke and mirrors".

    12. Re:"Smokers" by cellocgw · · Score: 1

      No problem: we'll scare the birds off with lizards, then use Chinese needle snakes to get rid of them, followed by snake-eating gorillas, and then we just need to make Africa have a winter.

      --
      https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
    13. Re:"Smokers" by Anonymous Coward · · Score: 1

      And you think the number of CSPs are ever going to get close to the numbers of buildings birds slam into? It'll never compare. Not to mention the pollution from a single coal power plant easily kills off more birds and other wildlife than the few that randomly fly through a "heat beam". We're talking a small number of birds compared to the already huge losses we take from the existing pollution producing coal power plants.

    14. Re:"Smokers" by Ungrounded+Lightning · · Score: 1

      Not sure about this installation, but one I read about in Australia was in the desert, where there are no birds.

      Huh?

      There are LOTS of birds in deserts.

      --
      Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
  12. Cheaper than diesel ? by Crashmarik · · Score: 1

    The only places that use diesel are areas that can't be properly served by other power plants.

    Requires no concrete, well seeing as the article didn't mention how they dealt with the problems concrete solves.(stability, weather resistance) I'll just chalk that up to another example of agenda driven reporting. Looking at the image a good wind will turn these things into tumble weeds.

    1. Re:Cheaper than diesel ? by Chas · · Score: 1

      Looking at the image a good wind will turn these things into tumble weeds.

      Actually, if properly staked in? Probably not.

      --


      Chas - The one, the only.
      THANK GOD!!!
    2. Re:Cheaper than diesel ? by Crashmarik · · Score: 1

      Looking at the photo they aren't

    3. Re:Cheaper than diesel ? by hvrbyte · · Score: 0

      I'm originally from South Africa (all of my family and a lot of my friends still live there).

      Everyone I know down there have diesel generators as backup. The state run utility can't provide enough power to supply the whole country which means that they institute "load shedding" quite often. What this actually means is that you can expect to be without power for 4 hour stretches on a regular basis as they roll these through the country.

      I went back there for an extended (8 month) visit last year and the power situation drove me nuts.

  13. Hate to say this but... by mikeiver1 · · Score: 1

    Likely this is true until the trackers built into the base go tits up. There were a number of these systems in the California desert in the 80s, don't hear about them any do we? To complicated and maintenance intensive to be practical and ultimately damages the reputation of solar. Simple high efficiency solar panels are most likely to disrupt the present power generation monopolies and allow us a bit more freedom from the handful of those that literally have the power in their hands. Consider this, where is the greatest growth in power generation happening throughout Europe and America, It ain't heliostats!

    1. Re:Hate to say this but... by Required+Snark · · Score: 1
      Living in the past? Are you traveling at relativistic speeds perhaps?

      Hey, Rip Van Winkle, it 2015, not 1980. Simple math. To make it fair, let's say 1990. 2015 minus 1990 equals 35 years.

      No change in electronics has happened since 1990, according to you. Are you posting here using your ASR-33 teletype or your DEC VT-100? Just wondering.

      --
      Why is Snark Required?
    2. Re:Hate to say this but... by Anonymous Coward · · Score: 0

      I think you should have stayed with 1980 for your mathematics to work out ;-)

      TBH I'm sure that these mirrors could self-guide themselves using a Raspberry Pi with a camera, and some image recognition/targeting software to keep sunlight aimed at the big block of salt.

      Alternatively, this could be a large scale Martian heat ray in the making...

  14. Currency, tracking and transport by AHuxley · · Score: 1

    What where South African power needs in the distant past? Mining, always ready rapid air defence for its decades long military needs, city, towns, advanced industrial use (eg Secunda and other projects).
    The power grid was a huge cost to expand everywhere over decades.
    Advanced tracking tilt heliostats can offer grid isolated communities a way to escape the traditional costs of diesel use with a generator at a remote location, delivery costs and currency exchange rate pressure needed to pay for all that domestic diesel use.
    Why pay for electrical energy in a foreign currency?
    Every hour of sun light can be understood on site to optimize the tilt angle every day to give some electrical power.
    With the power needs of water pumping, sanitation, farming, education, efficient led displays computers and lighting the needs for always on diesel power in remote sites may change. Domestic build costs, domestic tracking computing and engineering, lower long term costs, not having to buy or transport diesel over years to many remote locations could be a real plus for SA.
    Even exports given a local factory, the software, easy set up for appropriate global use.

    --
    Domestic spying is now "Benign Information Gathering"
  15. Why not? by Anonymous Coward · · Score: 0

    I had initial doubts, but a quick look at the pictures reveals that this could be true.

  16. Probably 15.0 kW, not 150 by subreality · · Score: 1

    They're claiming this enough to power 10 households, which would be 15 kW per house... Someone clearly dropped a decimal or doesn't understand units. 15.0kW or 150kWh/d is plausible. Math or GTFO:

    Google used ((862 heliostats) * (6 m**2 / heliostat)) to generate 890 kWe. Source

    890kWe / 5172 m**2 =~ 172 watts per square meter.

    Helio100 is using ((100 heliostats) * (2.2 m**2 / heliostat)) == 220 m**2. Assuming it's really 15.0 kWe, that comes out to 68 watts per square meter. The difference can easily be because Google optimized more for large-scale and efficiency instead of installation cost, whereas Helio100 optimized for smaller scale and minimum labor.

    1. Re:Probably 15.0 kW, not 150 by Anne+Thwacks · · Score: 1
      15kW per house? This is Africa, not America - typical usage in Europe is 4kW per house. It is probably 40W per house in Africa. Only 0.001% of houses have A/C.

      And, as pointed out elsewhere, most electricity comes from Diesel in Africa (The rest mostly from Hydroelectric).

      --
      Sent from my ASR33 using ASCII
    2. Re:Probably 15.0 kW, not 150 by Anonymous Coward · · Score: 1

      Holy crap can you be any more wrong?

      Firstly *SOUTH AFRICA* - it is a small country on the tip of Africa that shares very little in common with most of the rest of Africa. Secondly no most of our electricity does not come from Diesel or Hydroelectric, the bulk of our power comes from coal. Third, no, the general household usage here is probably at least 1kW at a minimum if not more.

      Seriously please just refrain from commenting on stuff that you clearly know nothing about.

    3. Re:Probably 15.0 kW, not 150 by Anonymous Coward · · Score: 0

      Hydro is only 0.1% of our power generation....

    4. Re:Probably 15.0 kW, not 150 by goose-incarnated · · Score: 1

      15kW per house? This is Africa, not America - typical usage in Europe is 4kW per house. It is probably 40W per house in Africa. Only 0.001% of houses have A/C.

      And, as pointed out elsewhere, most electricity comes from Diesel in Africa (The rest mostly from Hydroelectric).

      I'm South African. You're wrong. Usage per house varies from between 1kW to 4kW. Running a house on 40W basically lights a room dimly for an hour. Also, we have AC everywhere - I certainly have AC at home, at work and in my Mercedes-Benz.

      Oh, wait! You thought Africa was a poor *country*... silly you.. *South Africa* is a country in *Africa*, and we're more first-world than third-world.

      Idiot.

      --
      I'm a minority race. Save your vitriol for white people.
    5. Re:Probably 15.0 kW, not 150 by K.+S.+Kyosuke · · Score: 1

      Typical usage in Europe is around 400 W per household on average. 4 kW? What are you smoking? That would make two days of my energy expenses almost larger than my monthly bill.

      --
      Ezekiel 23:20
    6. Re:Probably 15.0 kW, not 150 by K.+S.+Kyosuke · · Score: 1

      If you're actually using around 2 kW on average (seems quite atrocious to me), it seems that you'd probably save a lot of money by running your AC from rooftop solar (unless there's some kind of glitch like red tape or extortionist pricing in the local market). Besides the power, you'd be shading the building somewhat.

      --
      Ezekiel 23:20
    7. Re:Probably 15.0 kW, not 150 by goose-incarnated · · Score: 1

      I personally (my home) use around 1kW on average. The problem with using solar is that the payback period (in SA, anyway) from electric bill savings exceeds the expected lifetime of the panels and related kit needed to set it up.

      --
      I'm a minority race. Save your vitriol for white people.
    8. Re:Probably 15.0 kW, not 150 by K.+S.+Kyosuke · · Score: 1

      In that case, you PV install prices must be truly atrocious if you can't amortize it even with modern equipment. It's either that, or your electricity is ridiculously cheap.

      --
      Ezekiel 23:20
    9. Re:Probably 15.0 kW, not 150 by Anonymous Coward · · Score: 0

      I know that everyone is fixated on a binary world these days where only one of two things can be true, so this may completely blow your mind.
      ITS BOTH, AT THE SAME TIME!

    10. Re:Probably 15.0 kW, not 150 by Coren22 · · Score: 1

      When did South Africa join NATO?

      http://www.nato.int/cps/en/nat...

      Oh, it didn't.

      http://www.nationsonline.org/o...

      First world is NATO aligned countries, second world is Soviet aligned countries, and third world is non aligned countries. You don't rise into the first world by improving conditions in the country, you do it by joining alliances.

      --
      APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
    11. Re:Probably 15.0 kW, not 150 by bullok · · Score: 1

      No. Typical usage in Europe is MAYBE 4kWh/year. Notice the difference between kW and kWh, please. They are very different - kW is power, kWh is energy. See: http://www.energylens.com/arti... for an explanation. You can find energy use for several countries at http://shrinkthatfootprint.com... Having said that, there is no way that 150kW powers only 10 houses. Louisiana uses more energy per household than any other state in the US (probably due to air conditioning): 15270 kWh per year (the average in the US is 10908 kWh). So, in Louisiana, a home is using (15270kWh/year)/(8765.81 hours/year) = 1.74 kW of power at any given time, on average. That means that a 150kW heliostat should power about 86 homes in Louisiana - during the time when the array is functioning (daytime, with some lag for heating up and cooling off). So, the article is not very useful, because it's not telling us how many kWh/day this heliostat produces. My guess is that they either got a decimal point wrong, or that 150kW measures the amount of solar power being CAPTURED, not the amount of power being GENERATED as electricity.

    12. Re:Probably 15.0 kW, not 150 by Anonymous Coward · · Score: 0

      Certainly in the Mid-Atlantic region of the Eastern US, we have both of those - fairly high costs to install and fairly low electrical costs (~$0.10/kwh). Add to that a relatively low average insolation (4.5 hours) and even with subsidies it's not a no brainer. Without subsidies, it doesn't make financial sense here.

    13. Re:Probably 15.0 kW, not 150 by Anonymous Coward · · Score: 0

      Actually, you're incorrectly pedantic. First world countries were non-Communist participants in the Cold War. Third world countries did not take a side. Second world countries were Communist participants in the Cold War.

      NATO literally has nothing to do with it, though they were a component of the Cold War and were a more or less accurate list at the time (less accurate as you'll see).

      South Africa took a position against the Cold War, and thus was a first world country. This due to Western European colonization of South Africa at the time. If you don't believe me, have a look at the map.

      https://en.wikipedia.org/wiki/First_World

      The list of First, Second, and Third world countries are frozen in time (Specifically whatever was your status on December 26, 1991) and immutable. A country can only cease to be First or Second world and become Third world by changing name/government (As a country that didn't exist during the Cold War could have no position on it). There's no way to become Second or First world at this time without a time machine, and even then, I'm not sure how that would work.

    14. Re:Probably 15.0 kW, not 150 by bruce_the_loon · · Score: 1

      You're all falling into the trap of average daily power usage. The heliostat needs to provide the peak power draw, not the average power draw of a house.

      I'm a South African and while my 3 person house averages 700W power consumption over a 24 hour period, my peak is close to 10kW if I've got the stove, water heater and kettle going at the same time. That happens regularly in the early evening or mornings. And yes, we have electric stoves and water heaters because we don't have a gas infrastructure like Europe or North America.

      Our electricity rates per kWh seem to be comparable to the US rates, 10 US cents to 14 US cents per kWh for my city's inclined tariffs. But solar installation costs are high, a 10kW installation with batteries to hold overnight can be around $25000 and the batteries will have to be replaced after 6-9 years at around $8000. My house uses roughly 1000 kWh a month for a bill of $110. So the capital cost would pay off over 19 years, but after a maximum of 9 years, I'd add another 6 years to that. And for the average working and middle class South African, $25000 as a capital expense is a harsh layout.

      --
      Trying to become famous by taking photos. Visit my homepage please.
  17. Power Outages by Anonymous Coward · · Score: 0

    The question is why there are regular power outages in South Africa? Do South Africans prefer a society on the brink of a collapse, all the time?

    1. Re:Power Outages by Anonymous Coward · · Score: 0

      Yes.

  18. Who needs sharks with friggin lasers ? by Anonymous Coward · · Score: 0

    Just hack the controllers, line 'em all up at the same target and watch the cities burn.

    (Credit to Larry Niven here)

  19. Re: Yet more vaporware by Anonymous Coward · · Score: 0

    It is already more reliable. This is Africa. Your diesel might get stolen in transit to fight a war or fund terrorism

  20. Wow, such BS by Maury+Markowitz · · Score: 0

    " offer solar energy that's cheaper than diesel."

    Diesel is an extremely expensive fuel. Comparing yourself to that, when conventional PV is 2 to 3 times cheaper already, seems very fishy indeed.

    http://www.lazard.com/media/1777/levelized_cost_of_energy_-_version_80.pdf

    1. Re:Wow, such BS by Tokolosh · · Score: 2

      The South Africans have mismanaged their power supply system to the extent that they now have to operate open-cycle emergency/peaking sets on diesel, continuously. This is very expensive, as you say, and is contributing to the downward economic spiral. Hence the grasping at straws.

      --
      Prove anything by multiplying Huge Number times Tiny Number
  21. Khyber, if ANYONE's a moron, it's you... apk by Anonymous Coward · · Score: 0

    "he's tying to get your fucking information." - by Khyber (864651) on Saturday August 22, 2015 @01:02PM (#50370415)

    My program doesn't transmit outward ONLY intake of data from 10 reputable sources in the security community!

    ---

    "NOD32 detects a trojan in APK's HOSTS bullshit." - by Khyber (864651) on Saturday August 22, 2015 @01:02PM (#50370415)

    VirusTotal & NOD32 SHOW IT COMPLETELY CLEAN IN ITS EXES

    https://www.virustotal.com/en/...

    AND

    https://www.virustotal.com/en/...

    There's only 2 exe's & 5 text files in it - The exe's are proven clean as shown above in the 2 links from VirusTotal, the installer's a SFX rar (keeps it 2mb smaller on download) - that's NO virus!

    (Unless YOU know of a way that .txt files are "viruses")

    ---

    "APK is apparently too fucking stupid to do this at the ROUTER level where it's most effective" - by Khyber (864651) on Saturday August 22, 2015 @01:02PM (#50370415)

    You believe in "eggshell security" which fails per -> http://www.theregister.co.uk/2...

    A TRULY COMPETENT NETWORK ADMIN WOULD DO FAR MORE THAN MERE PERIMETER LEVEL SECURITY @ ROUTER LEVEL!

    (Right down to the endpoints/network nodes level in PC workstations also using tools you already have in hosts + firewalls (vs. "piling on 'MOAR'" that's inefficient & not nearly as effective in slower usermode browser addons)).

    ---

    "Windows 10 has hardcoded IPs and bypasses HOSTs." - by Khyber (864651) on Saturday August 22, 2015 @01:02PM (#50370415)

    Windows ONLY bypasses hosts files for Windows update (Win8 & below) & for the tracking "telemetry" in Windows 10 (this is going to KILL Windows 10, mark my words - nobody likes tracking -> http://localghost.org/posts/a-... - test it yourself.

    ---

    "Browsers can bypass HOSTs as well." - by Khyber (864651) on Saturday August 22, 2015 @01:02PM (#50370415)

    WTF? They'd be bypassing the IP stack itself, hosts are part of it - since that's impossible? You've proven yourself a moron, again.

    APK

    P.S.=> See subject & "EAT YOUR WORDS"... apk

    1. Re:Khyber, if ANYONE's a moron, it's you... apk by Khyber · · Score: 1

      http://www.computerworld.com/a...

      http://simpleprogrammer.com/20...

      https://lonesysadmin.net/2008/...

      http://windowssecrets.com/lang...

      http://serverfault.com/questio...

      *YAWN* Try again when you're an actual competent system admin, APK. You're completely fucking useless, outdated, and even 5 year olds know better than you.

      --
      Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
    2. Re:Khyber, if ANYONE's a moron, it's you... apk by Anonymous Coward · · Score: 0

      Hey APK
      don't loose any sleep over this "Khyber" asshole...
      He probably saw sitting in the back of class with a pointed hat as an acknowledgement of his abilities. well, they certainly were!
      He 'Khyber" don't own shit & aint' got nothing! lives with his boyfriend cause he can't support himself and has serious psycho-socio-economic problems- He's just too stupid to do anything constructive, violent , aggressive temperament and can't even hold down a job delivering pizzas.
      IF that ain't the bottom of the barrel, what is ?
      Let the Idiot rant and rave... He'll be in Prison before to long, that's almost a guarantee !

    3. Re:Khyber, if ANYONE's a moron, it's you... apk by Anonymous Coward · · Score: 0

      KHYBER ( the Butt-Fuck Boy says):
      "he's tying to get your fucking information." - by Khyber (864651) on Saturday August 22, 2015 @01:02PM (#50370415)
      My program doesn't transmit outward ONLY intake of data from 10 reputable sources in the security community!

      SO, List your 10 Reputable sources in the security community here, for us all to see, Bitch!
      Khyber, Your Ass is OWNED

  22. LMAO, I don't... apk by Anonymous Coward · · Score: 0

    Can't think for himself (google junkie) & I broke him 2x -> http://tech.slashdot.org/comme...

    Khyber the MORON doesn't even READ HIS OWN LINKS HE POSTS... lol!

    APK

    P.S.=> He's an utter incompetent, a google junky @ BEST/MOST... & couldn't even get THAT right (he didn't read his own links fully there, & now I'm going to dismantle him on these too easily)... apk

  23. Dismantling dumbass Khyber yet again... apk by Anonymous Coward · · Score: 0

    Try again when YOU're actually competent in computing @ all Khyber:

    1st link is a KNOWN bug easily gotten around in Windows defender in Windows VISTA/8 (nobody bought those pieces of junk anyhow, lol)

    2nd link MY PROGRAM KEEPS YOU CURRENT AGAINST since it reverse dns pings ANY hardcodes you may use in hosts (THE MAJORITY OF THE FILE IS BLOCKED ADDRESSES OF KNOWN BAD SITES THAT IT PRODUCES, BY FAR, AS WELL).

    3rd link is about dns: That's wasteful for a home user in electrical power (especially if setup as another machine), HAS SECURITY ISSUES GALORE (kaminsky flaw redirect poisoning, 99.999% of ISP dns server aren't patched vs. it mind you), cpu cycles, RAM, & other I/O it uses PLUS it has a far more complex rules table vs. hosts (most users won't get it, hosts by comparison are easy to understand internally).

    4th link is from a "writer" (not even a competent sysadmin, who are helpless monkeys themselves minus PROGRAMMERS LIKE MYSELF CREATING TOOLS FOR THEM TO USE, them merely being users with a better password only, lol) - & wrong as hell: They ADMIT hosts work to block malware & can do hardcodes for faster LOCAL resolution from memory.

    5th link TRIES to make it sound like someone's trying to 'cache the entire internet' in hosts - even I don't DO that! I merely put where I spend MOST OF MY TIME ONLINE @ THE TOP OF HOSTS & once that caches into RAM here? I am DEFINITELY RESOLVING LINKS FASTER than calling out to a REMOTE DNS SERVER, stupid.

    YOU LOSE AS ALWAYS STUPID...

    APK

    P.S.=> My burning your ass here though, for YOUR STUPID MISTAKES, & TWICE? Priceless -> http://tech.slashdot.org/comme...

    ... apk

  24. Khyber = "the incompetent 'sysadmin'"... apk by Anonymous Coward · · Score: 0

    What's that YOU just said Khyber? Take a peek here everyone http://tech.slashdot.org/comme... & have him tell us that again... R O T F L M A O!

    * :)

    (Khyber - you're an UTTER total fool...)

    APK

    P.S.=> Not only did I totally SCORCH YOUR ASS point-by-"so-called 'point'" of yours in that 1st link above, but I also TOTALLED you on "hosts being Windows 98 technology" stupid (they're from UNIX) -> http://tech.slashdot.org/comme... AND on your "DESPERATION PLAY" errors you made by NOT READING YOUR LINKS YOU POSTED, in full http://tech.slashdot.org/comme... , moron, point-by-"so-called 'point'" of yours there...

    ... apk