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Power Hardware IT Technology

Can the Sun Realistically Power Datacenters? 237

Posted by Soulskill from the nobody-needs-wyoming-for-anything-important dept.
1sockchuck writes: A massive solar array in central New Jersey provides the daytime power for a server farm delivering online financial services for McGraw Hill. The 50-acre field of photovoltaic solar panels symbolizes a new phase in the use of renewable energy in data centers. Massive arrays can now provide tens of megawatts of solar power for companies (including Apple) that can afford the land and the expense. But some data center thought leaders argue that these huge fields are more about marketing than genuinely finding the best approach to a greener cloud.
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Can the Sun Realistically Power Datacenters? More

Can the Sun Realistically Power Datacenters?

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  • Obligatoriness Extraordinaire (Score:3)

    by Mr D from 63 ( 3395377 ) on Tuesday October 14, 2014 @05:12PM (#48144279)
    Lets just get this out of the way;

    As soon as they come out with them super whamodyne batteries, our problems will be solved.

    Proceed....

    • Re:Obligatoriness Extraordinaire (Score:5, Insightful)

      by saloomy ( 2817221 ) on Tuesday October 14, 2014 @05:23PM (#48144351)
      Can a certain number of solar panels power a datacenter with a given load? Sure! Just not 24/7. But that doesn't mean they can not. Your datacenter takes 1 MW/h. You receive roughly 8 hours of usable sunlight, so you need 3MW/h capacity of solar panels to produce the power you need. During the day, the power company will take your excess power, and light up factories, offices, Air Conditioning, etc... During the night, you will use the power company to power your datacenter, when it has to keep its power systems up anyways, and therefore has excess capacity. Look up the terms "base load" and "peak load", understand that not everything that plugs into the power grid needs to be up 24/7 ( not even all servers, look up "DRS"). So can that much power be produced to have a "net neutral" load on the grid? Sure!

      But there is always the desire to be completely self-reliant. In this area, I always liked the idea of using the excess power during the day to lift water to a lake high up, and running hydro at night to power the datacenter. This is of course expensive, especially since power companies have excess power at night anyways, since the cycle time to stop / start producing base power won't allow the company to shut down X generators at night.

      • Re:Obligatoriness Extraordinaire (Score:5, Interesting)

        by mcrbids ( 148650 ) on Tuesday October 14, 2014 @05:39PM (#48144477) Journal

        Sadly, there just aren't enough places with lakes to store anything like the amount of power we'd need to store. You also have to deal with transmission loss between the solar site and the point of use. There was this proposal a while back [greentechmedia.com] to use massive, carved granite/stone blocks to store power but it doesn't seem to have achieved much mention beyond its initial proposal.

        • You also have to deal with the transmission losses from the coal plant to the site where it is used (*facepalm*)

          If the whole grid is solar you only need to store about 100% of max usage.

        • Re:Obligatoriness Extraordinaire (Score:5, Insightful)

          by ShanghaiBill ( 739463 ) on Tuesday October 14, 2014 @06:31PM (#48144973)

          Sadly, there just aren't enough places with lakes to store anything like the amount of power we'd need to store.

          This is actually a silly concern. Electricity demand is highest in the middle of the day when the sun is shining. That is also when the spot price for power is highest. It makes no sense at all to store that power to sell it in the middle of the night, when prices are far lower.

          Storing solar power is an issue in niche applications, and it is an issue in a future fantasy world where 100% of our power is solar. But it is not an important issue in the real world, and is unlikely to be for a long, long time.

          • Re:Obligatoriness Extraordinaire (Score:5, Interesting)

            by Moof123 ( 1292134 ) on Tuesday October 14, 2014 @06:49PM (#48145135)

            The example of Prineville in TFA is a good one. Here in Oregon we have a lot of base load provided by hydroelectric. We have had squabbles between the Hydro guys and the Wind guys at night in winter when the Hydro guys need to keep the turbines spinning to keep the dam levels safe, and the wind guys have to stop feeding into the grid and that hurts their bottom line.

            Summer during the daytime is when Oregon fires up more of the of the coal and natural gas plants, so solar fits in well to cover these peaks times and seasons when the rain isn't falling, the snow has stopped melting, and the AC is running.

            Other regions are not nearly as lucky as Oregon to have good wind and hydro options, but lets not disqualify a technology just because it isn't a perfect fit everywhere.

          • Storing solar power is an issue in niche applications, and it is an issue in a future fantasy world where 100% of our power is solar.

            Very true, and not even a real issue in a 100% renewable scenario. The entire state of South Australia ran on 100% renewable power for a full working day for the first time last week. The bulk of that was wind generation, with rooftop solar adding a significant contribution.

            There have been several instances in recent months when wind energy has accounted for all, or nearly all, electricity demand in South Australia. Last Tuesday, however, set a new benchmark – the combination of wind energy and rooftop solar provided more than 100 per cent of the state’s electricity needs, for a whole working day between 9.30am and 6pm. There were several periods in South Australia from Saturday September 27, and over the following days, when wind generation was greater than total state NEM demand.

            In reality, renewables contributed well over 100 per cent because they were generating and consuming their own electricity from rooftop solar – the state has 550MW of rooftop solar, with nearly one in four houses with rooftop modules.

            That meant that “true” demand by consumers on that day, i.e. the amount of electricity being used by consumers, including rooftop solar, was in fact considerably higher than NEM demand — up to 20 per cent according to the Australian Photovoltaic Institute — because of the contribution of rooftop PV to total electricity supply.

            http://reneweconomy.com.au/201... [reneweconomy.com.au]

      • Re:Obligatoriness Extraordinaire (Score:5, Insightful)

        by Mr D from 63 ( 3395377 ) on Tuesday October 14, 2014 @05:39PM (#48144479)
        Average solar insolation is more like 5 sun-hours/day, not 8, in good locations. Much less in places like Germany. If you want autonomy on the shortest day of the year, you may have less than 2 full sun hours, which means 12 MW of capacity, but that doesn't account for a cloudy day, in which case you may get less than 1 full sun hour insolation.

        So, bottom line is there are a lot of ways to look at the numbers, but to be truly autonomous with no grid support, you need a lot of capacity.
        • The key fact is the Sun has vastly more capacity than we will need in the next few thousand years, let alone the next few decades. There's literally an oil well on every street corner. The difficulty for now is storing that for later use.

          You also touched on another key factor. When the fuel is free, efficiency of generation can be a very low priority. Sure it costs more to build a bigger array, but not nearly as much as trying the infinity cost of doubling your solar panel efficiency if the tech don

          • Re: (Score:2)

            by sl149q ( 1537343 )

            And take up more land.

            Increased solar means increased habitat destruction.

            Unlike Gas and Oil plants that produce plant fertilizer :-)

            • Unlike Gas and Oil plants that produce plant fertilizer :-)

              They produce bullshit?

            • data centers generally aren't lacking for available roof space so no taking up any more land. Hell give tech 10-20 years and the roads themselves will be providing us power. They have window films today that generate electricity.

              But keep sucking on that sweet sweet tail pipe o crude
              • Well, perhaps, but the roofs aren't enough. The cooling density of server racks is higher than the solar constant.
                • Glad we agree it's feasible then, just a matter of scale. We have lots of buildings just waiting to generate power while just 'sitting there'.

                  Nobody said they had to generate it all directly on site. And when the roads and every other manmade surface are producing power, habitat destruction will be the straw man it always was.

              • Re:Obligatoriness Extraordinaire (Score:4, Insightful)

                by Idarubicin ( 579475 ) on Tuesday October 14, 2014 @11:59PM (#48146975) Journal

                data centers generally aren't lacking for available roof space so no taking up any more land.

                Above the atmosphere, at the equator, the average insolation (that is, the amount of incoming solar energy, averaged over the course of a day) is about 400 watts per square meter. At the bottom of the atmosphere in an ideal location (like the Sahara) it's closer to 300 W/sq. m. In most places where people want to have data centers, the number is closer to 200 W/sq. m...or worse. And the efficiency of commercial solar panels runs about 20%, so you're down to 40 watts per square meter.

                200 watts is (optimistically) about the draw of a single server, so you're looking at powering one server for every five square meters of rooftop. If you want to run on rooftop solar, then you're going to have to design a data center with very short racks and very wide aisles.

        • Thats true if you do not have solar arrays that rotate to take advantage of the sun's maximum incidence, but in a commercial installation, thats non-sense. On a roof top, there are limitations such as aesthetics of having the panels flat against the roof, and maximum height of the structures that come into play that don't need to be considered for commercial installations. The commercial installations move their collectors to attain a maximum incidence throughout the day, by remaining perpendicular to the
          • I know you get it, just being a little more 'real world' with the numbers because a lot of folks don't realize how short the solar insolation day can be.

            An interesting thing about tracking panels. You might see more of them if battery systems came in to play. Right now, there is no incentive to pay for tracking systems, but rather plunk that extra money into more capacity because feed in tariffs and production credits don't care what time of day the power is produced, so why bother. Just put in more pane

            • Re: (Score:2)

              by dwywit ( 1109409 )

              My installer said that tracking systems aren't really worth it for domestic situations. They cost about the same as 2 extra panels, and provide roughly the same amount of energy - so why not buy 2 extra panels and not have to deal with maintenance of motors, etc.

              I thought that a tracking system could be set up to forego motors and use bi-metallic strips to drive the panel movement throughout the day - have the panels point east when "cold", i.e. in the morning, then bimetallic strips would warm with the sun

        • Re: (Score:3)

          by mlts ( 1038732 )

          Not just grid capacity, but battery banks. Conventional lead-acid batteries don't last a while. I've been reading good reports on Ni-Fe (Iron Edison is the main brand) batteries, while not as dense, have a 20+ year life.

          Of course, there are charge controllers to make sure you feed the power to the batteries at the right voltage and amperage. Too many volts, and lead-acid batteries will boil.

          With a source of fuel like propane or natural gas, going off-grid is doable, since a lot of heavy hitting appliance

          • Re: (Score:2)

            by dwywit ( 1109409 )

            Ni-Fe batteries have a long life and more tolerance for discharge levels, but poor efficiency compared to lead-acid. Doesn't mean they wouldn't be useful, but you'll need LOTS more panels to replace what you take out.

            My last set of lead-acid cells (12 x BPSolar 2-volt 1100ah) lasted 8 years of domestic use before the first one failed.

            You're right about the controller - a good controller makes all the difference.

        • Re: (Score:2)

          by dbIII ( 701233 )

          Average solar insolation

          Since most of the world's population are concentrated towards the equator that just indicates you either do not understand that your objection is mostly irrelevant or you are pretending to misunderstand to push an invalid point. True - solar is going to really suck in Alaska, Siberia and probably even Seattle but in a lot of places it's a nice addition to the energy mix in daytime when people are working and using up a lot of electricity.

          but to be truly autonomous with no grid suppo

      • I always liked the idea of using the excess power during the day to lift water to a lake high up, and running hydro at night to power the datacenter.

        The version I like is using excess power to pump air into an enclosed space, natural or artificial. Then at night, release the compressed air to drive a turbine. It seems more flexible than large water works. And in case of massive failure, you just get a loud noise instead of a million gallons of water everywhere. Datacenters and standing water door poorly together.

        A different variation is what they're doing at Solar Two in California. It's a "solar thermal" plant, but unlike other thermal plants that

      • Re: (Score:2)

        by sl149q ( 1537343 )

        Not quite.

        You need about double that to allow for losses pushing the power into storage and getting it back out.

        And you need some additional capacity for generation and storage to allow for days when you run at less than 100% efficiency. E.g. cloud cover or winter.

        So 1MW/h becomes 3MW/h becomes 6MW/h becomes maybe 10MW/h and you might have 1-2 days best case backup for bad weather.

    • Re:Obligatoriness Extraordinaire (Score:5, Interesting)

      by mythosaz ( 572040 ) on Tuesday October 14, 2014 @05:57PM (#48144647)

      We're already harnessing the power of the sun without "batteries" in the traditional sense. Most of the recent plants built (and under construction) here in Arizona are molten salt, which provides full power for three hours after the sun is "off" -- well into peak residential hours -- on residual heat.

      We're still nowhere near 24/7/365 coverage, but we're making strides.

      • Hold on there buddy. Those molten salt plants are still developmental projects. Extremely expensive and by nature very inefficient. Reliability is a big unknown as well. Lets let them get a few years under their belts before we count on them. And then consider that not everywhere has the ideal conditions that are found in Arizona.

        • Yeah, yeah, super duper experimental....

          On July 4, 2011, a company in Spain celebrated an historic moment for the solar industry: Torresol’s 19.9 MW concentrating solar power plant became the first ever to generate uninterrupted electricity for 24 hours straight, using a molten salt heat storage.

          Maybe you'd like to visit the 280MW Solana plant I've got here just outside of Phoenix? They're molten salt and churn out power three hours after dark (or six on other references).
          http://en.wikipedia.org/wiki [wikipedia.org]

          • OK, show us the operating record then. Reliability, cost per kwh, etc. That info is available for mature technologies.

            • Oh, snap! You've got me with your clever, "It just went online and works great, but it's not 'proven' so na-na-na-na!" line of reasoning.

              APS agreed to pay 14c/kWh for Solana's power, and Solana (for cocktail napkin purposes) makes 1 million MHh/year, giving it 14 years to return the 2BN it cost to build, before operating expenses. It's the largest plant by far currently online in Arizona, and no large plants have been operating for 14 years here yet, so the answer is, "We'll see."

              The first kWh of electric

              • Don't mix price and cost.

                $2B for 250 MW isn't that bad if it has a high capacity factor. Of course, equipment lifetime and maintenance costs become a big deal. Reliability as well, if the plant shuts down it takes a long heat up period before it can produce electricity again. It also appears to require gas backup, how often is uncertain. The biggest question is lifetime of major costly components. If they last 5 years, not a good deal. If they last 15, then its probably a wash. All those things fall in t
                • So if he gets back to you in 15 years and all is well, you'll concede?

                  • "OK Google, remind me in 15 years to gloat."

                  • 15 years is, what I would say, bearable. That is, if it proves to be highly reliable. That must include all costs, not just the initial CAPEX. If the thing will work for 30 years without complete overhaul, even longer might make sense. If high maintenance costs and a lot of down time are seen, and so there needs to be extra reserve to compensate, then the payback better be a whole lot shorter.

        • Reliability is a big unknown as well

          Molten salts of various types have been used on an industrial scale for steel heat treatment since the late 19th century. A bit about warming them up, cooling them down and so on has been picked up over that time.

          And then consider that not everywhere has the ideal conditions that are found in Arizona.

          You are correct, it is unlikely to work at your desk in an airconditioned office in the middle of a city. Meanwhile there are coal fired power stations already using solar

  • At least the infrastructure is in place (Score:5, Interesting)

    by racermd ( 314140 ) on Tuesday October 14, 2014 @05:24PM (#48144371)

    It may be a drop in the bucket now (Facebook's 100kw solar array for a facility consuming 25Mw is just that), but the infrastructure is in place to put in better panels later as they're developed. Additionally, if using otherwise "wasted" space (such as a rooftop), why not put it in place? The long-term power cost savings for such a facility (that is planned for the long term, anyway) will eventually pay for for the system a few times over, even if the impact to overall energy usage is that proverbial drop in the bucket. In other words, it makes business (read: financial) sense to do it.

    • Re:At least the infrastructure is in place (Score:5, Interesting)

      by ArcadeMan ( 2766669 ) on Tuesday October 14, 2014 @05:28PM (#48144399)

      If you have solar panels on a rooftop that would otherwise be cooked by the sun, aren't you also saving on the amount of power required for air conditioning?

      • Depends how well it is insulated.
      • If you're trying to heat the building - not so much. If the panels are in contact with the building - not then either - they tend to capture a lot of heat. If you get them far enough away that outside air removes the heat - then shade may help.
        • All else being equal, if you put solar panels on a building that you are also cooling, the building will be cooler as a result of some of the sun's energy being converted to electricity. Basic conservation of energy.

          • All else is not equal. If you didn't have solar panels up there, you could put some light-colored paint on the roof, which reflects much of the sunlight. Solar panels tend to be quite dark, and get quite hot since they aren't anywhere near 100% efficient.

      • Re: (Score:2)

        by linatux ( 63153 )

        Any idea what percentage of the sunlight that would normally get reflected back into space now gets turned into heat?

    • Re: (Score:2)

      by AmiMoJo ( 196126 ) *

      If you have the cash on hand solar is a good investment. It's safe, guaranteed to pay back in a few years, and ethical.

      • Re: (Score:2)

        by mspohr ( 589790 )

        I just installed solar panels. Works out to a guaranteed 7% return on investment with no risk. The return should increase in future years as electricity prices rise.

      • guaranteed to pay back in a few years

        Gonna need to see the math on that one.
        Please show your work.

        • All it takes is a local utility that's exploiting it's monopoly and doing some serious price gouging for the panels to pay themselves off in a few years - and that applies in a depressingly large number of places.
          Now if it was the utility themselves with the panels that's a much longer payback time. The gap between generating costs and retail price is enormous nearly everywhere and keeps increasing. Where I live it can be as low as 3 cents per kilowatt hour for the wholesale rate and in excess of 30 cents
    1. Can't energy not being used be stored in batteries that can be used later?
    2. What's the environmental impact of these arrays taking up so much land versus the emissions they're cutting down on.
    3. Nevada, I can understand, but New Jersey? Not only do they get less sunlight, they also have less real estate.

  • Q: Can the sun power clouds? (Score:5, Funny)

    by MrEricSir ( 398214 ) on Tuesday October 14, 2014 @05:36PM (#48144455) Homepage

    A: Yes. It's called "evaporation." Next question, please.

  • The second link brings up Solyndra and government loan guarantees.
    The author conveniently leaves out the fact that Solyndra's failure was a direct result of China dumping solar panels onto the market.

    The USA and China have been fighting a slow motion battle at the World Trade Organization over solar subsidies and tariffs.

    In 2012, the USA slapped billions in tariffs on Chinese products.
    In 2014, the WTO said that the USA overstepped with its tariffs.
    Then the Chinese appealed the WTO ruling [reuters.com] even though it was

  • The sun is powering data centers all over the place right now... albeit from light it shined down on earth millions of years ago.

  • If they were serious about going green, they would rather than move their data centers here, in Quebec, Canada. We have a lot of electricity surplus generated by hydro-power plants. Their solar panels will never be able to be price competitive with our electricity and we have no problem to provide enough power at night. We can surely power the whole data centers, all of them. They can even build them next to the goddam damn to make the power wires as short as they wish to make the power supply reliable.

    Are

  • They need to integrate the 'solar farms' with pasture based farming. You can graze sheep, chickens, ducks, geese, cattle and goats under these solar arrays. It ends up like a savannah with filtered moving patches of sunlight and shadow. Very effective for pasture. Plenty of light gets to the forages for growth and the animals trim the forages so brush doesn't grow up in the fields. This avoids the need for mowing - a user of fossil fuels or at the very least electricity and time. Unfortunately, too few of t

  • Can the Sun Realistically Power Datacenters?

    Therefore the answer is: No

  • Short answer: No

    Long answer: No. Because the tradeoffs just aren't worth it, considering that you'd have to invest in a solar field nearly 400 times the size of your data center and you'd have to allot still MORE space for a HUMONGOUS unobtainium battery setup to store power in off-production hours.

    Then there's the environmental impact of clearing that much land just to let it like barren and house all those panels.

    We won't even go into the issues of the environmental impact of actually MANUFACTURING that

  • A massive chunk of the energy requirements for a datacentre is getting the heat out of the place. Using solar thermal heat pumps works at that sort of industrial scale and it's now commercial instead of just experimental.

  • If rich companies like Apple and FB want to burn cash seeing what it's like to do large solar deployments, for fuck's sake SHUT THE FUCK UP AND LET THEM! "Oh no, this problem can't be 100% solved overnight, so no one should be trying anything at all!" No, they won't cover 100% of their power bill on the first day, but they'll cover some of it, and they'll learn a lot along the way, and it's only going to get better over time. By the time it IS viable, they will have already reached capacity and paid off all

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