Become a fan of Slashdot on Facebook


Forgot your password?

Tesla Runs an Entire Island on Solar Power ( 191

Jon Fingas, writing for Engadget:Now that Tesla has officially acquired SolarCity, it's not wasting any time showing what the combined entity can do. Tesla has revealed that it's running the island of Ta'u (in American Samoa) on a solar energy microgrid that, at 1.4 megawatts, can cover "nearly 100 percent" of electrical needs. It's not just the 5,328 solar panels that are key -- it's the 60 Tesla Powerpacks that offer 6 megawatt-hours of energy storage. While Ta'u is normally very sunny, the packs can keep it running for three days without sunlight. They don't have to worry about a cloudy day leading to blackouts. The solar switch, which took a year to complete, has both its long-term environmental and immediate practical benefits. Like many remote communities, Ta'u previously had to run on diesel generators. That burns 300 gallons of fuel per day, which is neither eco-friendly nor cheap. Solar eliminates the pollution, of course, but it also saves the cost of having to continuously buy and ship barrels of diesel. And crucially, it provides a more reliable source of electricity.
This discussion has been archived. No new comments can be posted.

Tesla Runs an Entire Island on Solar Power

Comments Filter:
  • by WillAffleckUW ( 858324 ) on Tuesday November 22, 2016 @03:28PM (#53341475) Homepage Journal

    As indicated, shipping fossil fuel has high costs, and operation is noisy. Sunlight works even on cloudy days, and you can run desalination plants using solar, and it withstands weather effects fairly well.

    Many islands operate with a hybrid solar and wind system, especially in equatorial regions.

    • As a counterpoint, note that where I live we had a pretty solid overcast for five days last week.

      That said, yah, solar is a perfectly usable system when you have to ship any other fuel in across the Pacific, and when you don't need power 24/7.

      • Re: (Score:3, Informative)

        by Anonymous Coward

        However, overcast does not mean no power from solar. With the reduce power from the solar panels plus the batteries being fully charged to run for three days you probably have enough power to run six to seven days before the batteries are totally drained

        So it is very unlikely that you will have too little sun in a tropical island to keep it running.


  • How much did 1.4MW and 60 battery units cost? What is the buyback period compared to burning 300 gallons of diesel per day?
    • Re:Cost? (Score:4, Insightful)

      by Yvan256 ( 722131 ) on Tuesday November 22, 2016 @03:36PM (#53341537) Homepage Journal

      Don't forget the shipping cost of those 300 gallons of diesel per day, the maintenance and parts required for the generators, etc.

    • by guruevi ( 827432 )

      Wholesale diesel costs about $1.5/gallon. A day of diesel for the island thus costs ~$450/day, with shipping and storage probably about 20k/year. A set of generators for 1.5MW probably costs about 500k, and the same in maintenance over 10 years especially in a remote area. So you're talking about at the high end (with land, storage, regulatory and fuel cost increases) $1.5M investment once all is said and done.

      Solar currently costs about $1/W. 1.5MW is thus about $1.5M and lasts 20 years with a lot less mai

  • The summary is I think a bit misleading in saying how expensive the fuel is, while not giving any figures for how much the solar panels plus battery cost... I would love to know how much diesel all of that money could buy...

    That said there are a lot of fantastic benefits of being totally independent for energy and not having to rely on fuel shipments and being immune to price fluctuations, so you can't just look at the monetary cost and say it's not worth doing.

    • by ledow ( 319597 ) []

      It tops if you do certain things but at 2000 KW for 3 hours (should be 6 MW hours of total storage?):

      Roughly $2,751,100.

      • Re: (Score:3, Informative)

        by ledow ( 319597 )

        At $2.50 a gallon (seems to be current US price?), 300 gallons a day costs $750.

        Which means that THE BATTERY for that system that runs for 3 days only without solar would cost the equivalent of 10 years of diesel.

        Sure, there's a lot of losses, shipping, conversion, other equipment on the diesel side, but there's also a lot of solar etc. required on the Tesla side that's unaccounted for above. And it would take 10 years to break even just on the battery storage alone, let alone the solar + battery.

        Sure, it'

        • by Fire_Wraith ( 1460385 ) on Tuesday November 22, 2016 @04:02PM (#53341719)
          You're thinking of the US cost. That's going to be a lot different on an island like this in the middle of the Pacific Ocean. Take that $2.50 per gallon, and multiply it by the cost of shipping to Samoa. At an offhand guess, you're talking anywhere from 5 to 10 times as expensive.
        • At $2.50 a gallon (seems to be current US price?), 300 gallons a day costs $750.

          If you're buying it at a pump in the US, sure. If you have to load it onto a plane and send it to the easternmost volcanic island in the Samoa chain, it's going to be a touch more expensive. In Hawaii, for example, (which contains major air and sea infrastructure), diesel is over $4 per gallon. American Samoa is about 2600 miles from Hawaii, or 1800 miles from New Zealand. A chartered flight to the airport on this island from the capital of American Samoa is about $4,400 (obviously, not including the co

          • I don't know what the situation is there, but boat-to-shore pipelines do exist. Or, they could use shuttle boats. The idea of flying in fuel for routine use, to a Pacific Island, is just funny.
          • with a maximum cargo capacity of around 8,000 lbs, or about 4200 gallons of diesel, or enough for 2 weeks of power generation.

            Actually, diesel weighs about 7.1 lbs/gallon so you can only carry ~1100 gallons.

        • by Kinematics ( 2651345 ) on Tuesday November 22, 2016 @04:36PM (#53342033)

          Diesel cost in Samoa as of last July (quick Google check) was $2.06 to $2.28 per liter. That's between $7.80 and $8.63 per gallon. Call it $8.00. 300 gallons per day, 365 days per year, gives an annual cost of roughly $876,000. A $2.75 million battery cost would be paid for in saved fuel costs in a little over 3 years.

          Still have to figure in the solar panel costs. It's a 1.4 MW microgrid. Current Google response on solar panel costs is $3.57 per watt. There's federal compensation for solar installations (~30%), but I have no idea whether they'd be able to get any funding/credit for that, given that it's not a home installation. So going with the $3.57 value, 1.4 million watts would cost $4,998,000.

          Total cost is thus $7.75 million. Figure maintenance costs balance out with the diesel setup (less to break, more expensive per break), so no real effect there.

          Total buyback cost in terms of diesel fuel would thus be slightly under 9 years, not counting inflation or continued increases in fuel prices. Allowing for cost fluctuations, you could then say that the entire solar grid plus batteries should for itself within 10 years, which is a pretty decent rate. As long as the replacement time is significantly above that, it's a good deal.

          • Solar panels can be had for closer to 50 cents per watt these days. The cost you found is average installed cost on a house roof. The cost should be substantially less for a grid scale installation.

        • by necro81 ( 917438 )
          The cost of electricity on a remote island is very different than just the cost of the fuel on the mainland. You have neglected the cost of getting the fuel there and the cost-of-ownership for the diesel generators.

          Another approach to costing this system out, since sadly the article itself gives no numbers, is to consider the retail cost of the electricity. A handy comparison is Hawaii - another island location that, until recently anyway, generated almost all of its electricity from diesel shipped fro
        • by idji ( 984038 )
          you are also not considering the irregular arrival of ships for the diesel, and the effort of deshipping and handling the diesel. All of this completely disappears.
        • Well, there's a reason they're doing this kind of trial/test run on this island. Of course it won't immediately be at maximum efficiency, but that's why things like this are done. To learn how to do it better in the future.

          Give Tesla a few years of practice at these sorts of deployments, allow for greater economies of scale, and the costs will go down dramatically.

          What you're saying is essentially akin to claiming passenger air traffic is impossible, based upon the results at kitty hawk.

        • by snadrus ( 930168 )

          Other dimensions than today's price:
          - Inflation: What will Diesel cost in 10 years?
          - Politics: Will there be a consistent political climate to allow diesel to arrive from somewhere?
          - Availability: We could run out of oil one day. Reliable energy seems smart.

        • And it would take 10 years to break even just on the battery storage alone, let alone the solar + battery.

          So years 11+ are free? Where do I buy one?

          Sure, it's not linked to oil prices, but it's still only just verging on "viable" assuming nothing ever goes wrong. Same as every "green" project I've ever done the numbers for.

          Trajectory is just as important as position. Solar/Battery are getting cheaper every year. So if it's barely viable now it would follow that it will be absolutely viable soon, and really really viable later on? And we shouldn't bother because why exactly?

          • So years 11+ are free? Where do I buy one?

            Call Solar City, tell them I sent you, we both get a free month and I get $100

  • Mold (Score:5, Interesting)

    by marklark ( 39287 ) on Tuesday November 22, 2016 @03:28PM (#53341481) Homepage

    While the idea of a sunny Pacific island may seem like an easy and ideal place for solar power, this may not be the case.

    When I worked for NOAA, I heard wild stories about how the molds in Samoa would destroy our scientific instruments. They would even eat glass... This should prove an interesting and challenging situation.

    • by hjf ( 703092 )

      Fungus regularly eats camera lens glass. It sounds like exotic tropical island stuff, but it happens in closets all over the world, where grandpa's camera is rotting away.

      • Re: (Score:3, Interesting)

        by SubtleGuest ( 967971 )
        It isn't eating the glass it is eating the coating on it. No organism eats glass as an energy source.
        • by marklark ( 39287 )

          You haven't been to Samoa. Heat, humidity, molds, time -- a very effective destroyer of hardware (even glass). See the AC's link for something similar...

      • Re:Mold (Score:4, Interesting)

        by dwywit ( 1109409 ) on Tuesday November 22, 2016 @04:01PM (#53341705)

        It doesn't "eat" it. The fungus grows between lens elements. It seems to like the glue. Lost a nice Nikkor 200mm lens that way. It's fixable, but not economic to do so.

        The PV frames would (unless pre-emptively treated) corrode in the salty, damp air, but as they sit in harsh sunlight for extended periods, I think fungus would be somewhat down on the list of problems. Salty air can kill domestic computers inside 1 year, so junction boxes, blocking diodes, micro-inverters, etc would all have to be treated with sealant before installation. Same with all the controller circuitry, chargers, inverters, etc.

        Today's price of diesel in Brisbane - AUD$1.13/litre
        300 litres/day x 365 days = AUD$123,735.00 per annum
        Transport and maintenance of fuel and gensets = ?

        The payback period needs to be shorter than the Panel/battery system's expected lifespan, but as someone else has pointed out, there are benefits other than economic.

  • massive solar plants combined with massive desalination plants. Sadly it looks like it's just time for more tickle down economics. I'm really not looking forward to all the money that's about to get repatriated. There was an article on cnn with a whole mess of CEOs salivating over all the Mergers and Acquisitions they're gonna do. I wouldn't care if ever round of M&A didn't end in massive layoffs...
    • by jonwil ( 467024 )

      Trump said he would oppose the merger of AT&T and Warner Bros which sounds like he isn't exactly going to be conducive to a while bunch of anti-competitive mergers...

      • He has already backed off prosecuting Hillary, how many more statements will he back off of?

        • He's even waffling [] on the Paris deal, so it's quite possible that many of the people that supported him may find he's not as keen to fulfill all his campaign promises as they hoped.

        • He has only said that it's not on the top of his priority list, he didn't say that he'd block any investigation. If Jason Chaffitz asks him for a Special Prosecutor, he may likely get it.
          • I think we all know there is little to no likelihood of Clinton being investigated, much as there isn't going to be a wall or a Muslim registry.

            • by Jeremi ( 14640 )

              I think that if there is one thing everyone should have learned from the 2016 election, it's that the words that are heard coming out of Trump's mouth on any given day N are no indication of what his words or behavior will be on day N+1 or later.

              You might as well listen to a white noise stream; there's an equal amount of useful information present, and it's a lot more soothing.

  • Now all he needs is a monocle.
    • Don't forget about his plan to nuke the Martian polar ice caps: []

      For a while after that, he changed his twitter picture to that of him holding a long-haired white cat, so at least he has a sense of humor about it... well, that or he really is one:

      "Do you expect me to talk, Elon?"
      "No, Mister Bond, I expect you to buy my electric car."
  • by powerlord ( 28156 ) on Tuesday November 22, 2016 @04:05PM (#53341759) Journal

    This is the perfect proof of concept that Musk is aligning all the pieces needed for Mars Base 1.

    SolarCity for the energy collection
    Tesla for the storage and local transportation
    SpaceX for the "long haul" to/from Mars, as an umbrella for the expedition and for the environmental pieces (habitat design, space suits).

  • Since not all "entire islands" are created equal, I used Wikipedia so you do not have to.

    "The land area of Tau Island is 44.31 square kilometers (17.11 sq mi) and it had a population of 873 persons as of the 2000 census.
  • by tomhath ( 637240 ) on Tuesday November 22, 2016 @04:38PM (#53342057)
    That part of the world has very reliable trade winds. One wind turbine could generate several times as much power and would probably cost much less.
    • by dwywit ( 1109409 )

      It's the crazy gusts you get with cyclones that are the problem, but you're right about wind power generally in those 'trade winds' locations.

  • In remote areas where there is no existing grid infrastructure Solar is already cost competitive. Many parts of India which are off the grid are running on a mix of Solar and Biogas plants(basically farm waste and cow shit in a sealed tank with a pipe to draw out the methane). An Island where fuel needs to be shipped in is ideal for Solar and wind as it gets rid of the uncertainty of the fuel ship being delayed by a storm. However the locals need to be trained to fix the solar panels and batteries themselv

  • by Gonoff ( 88518 ) on Tuesday November 22, 2016 @05:31PM (#53342515)

    Orkney, a group of islands of the north coast of the UK is apparently now self sufficient in electricity from wind turbines. Yes we still have a diesel fired power station in case of problems and an undersea link to the UK national grid.

    This is the future - solar, wind, whatever, not filthy fossil power pushed by some bad tempered businessman with dodgy hair.

  • Filthy Space marines wouldn't. They would have been brainwashed into beliving in "clean coal" or some other such nonsense.
  • by PPH ( 736903 )

    Another evil genius builds a secret lair on an island under a volcano.

"Ask not what A Group of Employees can do for you. But ask what can All Employees do for A Group of Employees." -- Mike Dennison