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Businesses Technology

How Wind and Politics Pushed the Price of Texas Electricity Below Zero 211

Slate dissects the strange circumstances that led the price of electricity in Texas to briefly dip not just to zero, but into negative territory, reaching at one point negative $8.52 per megawatt hour. Why? A combination of being an "electricity island" with only weak ties to the surrounding state's grids; strong wind in a state that's sprouted thousands of windmills; and infrastructure design that means the only real buyer for most electricity producers' output is ERCOT, the Electric Reliability Council of Texas. (One of the comments attached to the story notes that Texas is not completely isolated from the national grid, but it's still markedly isolated.) A slice: Demand fell—at 4 a.m., the amount of electricity needed in the state was about 45 percent lower than the evening peak. The wind was blowing consistently—much later in the day Texas would establish a new instantaneous wind generation record. At 3 a.m., wind was supplying about 30 percent of the state’s electricity, as this daily wind integration report shows. And because the state is an electricity island, all the power produced by the state’s wind farms could only be sold to ERCOT, not grids elsewhere in the country.
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How Wind and Politics Pushed the Price of Texas Electricity Below Zero

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  • by Mr D from 63 ( 3395377 ) on Sunday September 20, 2015 @08:35AM (#50560485)
    Wind farm owners get lots of taxpayer help paying for the construction of the wind farm, then forced production credits means they get paid if power is needed or not. Apply this to any generation technology and the result would be pretty much the same.

    The model is even worse in place where the grid is forced to purchase power a even higher rates.

    In this model, who pays for the reliable backup?
    • by beelsebob ( 529313 ) on Sunday September 20, 2015 @08:37AM (#50560487)

      Which is great news! Texas is ahead of the world now in being prepared for the huge increase in electricity usage that good electric cars will cause.

      • by bertoelcon ( 1557907 ) on Sunday September 20, 2015 @08:42AM (#50560499)

        Which is great news! Texas is ahead of the world now in being prepared for the huge increase in electricity usage that good electric cars will cause.

        That won't do much good though, Tesla still can't sell in Texas without going through a bunch of hoops for a dealership.

        • Re: (Score:3, Insightful)

          by Anonymous Coward

          If you can afford a Tesla, you have no problem going a state over and buying them. I see plenty in Austin.

        • by Forgefather ( 3768925 ) on Sunday September 20, 2015 @10:48AM (#50560891)

          Speaking as someone who lived in Texas for 5 years. I saw more Teslas there than anywhere else I have traveled. Not being able to sell them in the state has done nothing to stop people from getting them. Every single grocery store has electric chargers out in front, as well as every apartment complex. Just on one street I could have had access to over 15 chargers. Electric cars were very popular in Dallas.

        • by mlts ( 1038732 )

          There are still a ton of Teslas on the roads here (well, namely Austin.) People just buy out of state and bring them here, and Austin has a repair depot for them, so one isn't SOL when they need maintenance.

          I do agree, Texas needs to get with the times... if someone is going to buy a Tesla, they will, and the TT&L money is going to go to Texas or another state.

      • Re: (Score:3, Interesting)

        Which is great news! Texas is ahead of the world now in being prepared for the huge increase in electricity usage that good electric cars will cause.

        Why? Because for a brief moment when electrical usage was at it very lowest (3 am, September day, little heating or cooling) and wind average is blowing at record highs they can supply 30 of demand? How is that world leading? They did accomplish showing how skewed the market had become, that is a form of leadership.

        • Probably almost no heating, but still probably a lot of cooling. In mid-September, overnight temps in Texas are still above where most people set their thermostats, plus the house is still radiating heat collected during the day, some of which goes inward. Even with the thermostat set at 78 in a relatively young house (11 years) built with good insulation, here in Dallas the AC still comes on regularly throughout the night.

          • Can you name a time when you expect much lower demand overall?
          • Just to enter some real numbers into the discussion, I checked ERCOT annual demand for 2014, Mid to late Sept early mornings show loads to be in the lowest 10% generally, with March and Oct early morning hours really being lower. So you are right, it is not the very lowest, but it is close.
      • by Sqr(twg) ( 2126054 ) on Sunday September 20, 2015 @09:06AM (#50560569)

        Nope. A negative price of electricity is not a sign that electricity is going to be cheap on average. On the contrary, it is a sign of poor infrastructure and heavy dependence on fossil fuel. (Coal and oil fired plants are expensive to take off-line, which is why the price of energy fluctuates wildly when the wind changes.) With better infrastructure and more hydro power, the price would not have fluctuated into negative, but would have been lower on average.

        • by Solandri ( 704621 ) on Sunday September 20, 2015 @01:10PM (#50561623)
          If you RTFA, the negative price is a consequence of a demand constraint (only ERCOT can buy the power) and a federal subsidy for wind generation. Normally when supply exceeds demand, the market price drops to below the cost to make some of that supply. It becomes not worth it to keep operating generators which are more expensive to run, and supply decreases to match demand.

          In this case though, there's a $23 per MWh federal subsidy for wind power. I dunno why the summary left that out since that's the most important piece to this puzzle. So even though wind producers are having to pay others $8.52 per MWh to take the electricity off their hands, they're still being paid $23 per MWh to produce it, for a net income of $14.48 per MWH. So they're still running their wind turbines at full even though the price is negative, because to them the price is still positive.

          The subsidy is the main reason the price went negative. The other reasons you cite contributed. The lack of power exchanges with other states meant the excess electricity couldn't be sent to other places where demand still outstripped supply. And the incentive to keep nuclear and coal operating (oil and gas can ramp up and down almost as easily as hydro) meant wind could push the price negative even though it was providing just 30% of the power. But the subsidy was the main culprit. If there were no subsidy, the wind turbine operators would've simply feathered their turbines and ceased production before the price went negative.
          • You are half right and half wrong.

            The price went negative because the ERCOT *must* buy the power to keep the grid stable. Otherwise the surplus energy would cause the grid to crash.

            Behind that might be the market you explained ... but equally important are the laws of physics.

          • I forgot to mention: it is hard to believe that the state is subsidizing a produced 1MWh with $23 when the price at the european spot market is something like 5cents per MWh.

            More likely they subsidized the construction of 1 MW (note the missing h) production capacity with $23.

        • A negative price of electricity is not a sign that electricity is going to be cheap on average.

          It doesn't need to be cheap "on average" for ELECTRIC CARS. Electric cars are happy to wait to be charged until rates are at their lowest, late at night. Most owners already set their chargers to wait until midnight, when prices drop. And most of those same owners install solar panels, too, to greatly reduce their peak/daytime power consumption, too.

        • by tomhath ( 637240 )
          FTFA:

          even if wind operators give the power away or offer the system money to take it, they still receive a tax credit equal to $23 per megawatt-hour.

          Wind farms can afford to give electricity away or sell it at a loss; they still make a profit because of subsidies.

      • by Chas ( 5144 )

        Which is great news! Texas is ahead of the world now in being prepared for the huge increase in electricity usage that good electric cars will cause.

        You missed the part where this happened at 4AM.

        So this surplus is ALMOST as useful as high tide is to a guy buried in the sand at the low tide mark.

        • by ShanghaiBill ( 739463 ) on Sunday September 20, 2015 @09:52AM (#50560685)

          You missed the part where this happened at 4AM.

          Electric cars can be pre-programmed to charge at any time. My wife has a Tesla, and hers is set to start charging at 2am. Our house has a smart-meter that records time-of-use, and our rates are lower at night.

        • Because you know, electric cars can't be set to charge during the night, and electricity companies don't encourage owners to do exactly that with plans that make it cheaper.

          Oh wait, yes they can, and yes they do.

          • There was talk of using the smart meters and the cars inboard computers to negotiate and in some cases, sell back electricity to the utilities during peak times.

        • Which is great news! Texas is ahead of the world now in being prepared for the huge increase in electricity usage that good electric cars will cause.

          You missed the part where this happened at 4AM.

          So this surplus is ALMOST as useful as high tide is to a guy buried in the sand at the low tide mark.

          One of the article points is that Texas is not hugely interconnected with other electrical grids. If it were, that electricity could be easily sold elsewhere. At that hour, things are winding down on the west coast and just getting started on the east coast. I imagine there's a demand for that power somewhere.

        • It would have been a good time to charge up BOB [popsci.com] the Big 'Ol Battery in Presidio Texas; it probably takes 40MW/hrs to charge that sucker up.

      • Which is great news! Texas is ahead of the world now in being prepared for the huge increase in electricity usage that good electric cars will cause.

        Cart before the horse - and likely decades and tens of billions of dollars before the need is there. What a waste. And that's the tragic part... wind/solar are currently a massive waste of resources.

    • I'm sure the savings will be passed on ha ha.
        The average cost of electricity here if you average all the suppliers somewhere around 10.5 cents per kilowatt hour I think it's just another way that using it for collecting taxes here .

    • Re: (Score:2, Informative)

      by Anonymous Coward

      It is not a problem with the generators. The main issue is that Texas regulation only allows selling to ERCOT. I'm sure that they would have loved to sell to someone in New Mexico, Oklahoma, Louisiana, or some other nearby state, even if it was for pennies. With a legislated single seller, there is no possibility to fix things, unless you want to legislate that ERCOT must buy electricity providing a fixed profit margin to the Wind generators

    • by Shoten ( 260439 ) on Sunday September 20, 2015 @09:35AM (#50560643)

      Wind farm owners get lots of taxpayer help paying for the construction of the wind farm, then forced production credits means they get paid if power is needed or not. Apply this to any generation technology and the result would be pretty much the same.

      The model is even worse in place where the grid is forced to purchase power a even higher rates.

      In this model, who pays for the reliable backup?

      Actually, this isn't true at all. Wind farm owners are participants in ERCOT like any other generation facility; if there's too much power on the grid, they are given directives to throttle down, even to zero if necessary. This applies whether the wind farm owners are a larger utility (like CPS Energy, Centerpoint, etc.) or a standalone entity with only wind farm generation.

      The reason behind this is simple; sink (also known as load) and generation must be in balance. You can't just "do" something with surplus power on the grid...it impacts both the voltage and the frequency of power. The second is the more frightening result, as over/underfrequency events do enormous damage to many different components of the bulk electric system. Even a difference of half a cycle (in power, a cycle is 1/60th of a second) is catastrophic.

      • Did you read the article?
        So, what are you contending is not true?

        1) Wind farm owners get taxpayer help with constructi0n?
        2) Wind farms get forced production credits?
        3) Forced production credits at higher rates have greater impact on the market?


        They are all quite true, and verifiable. The reason there is surplus power is due to the forced production credits, otherwise they would shut down and not produce during those periods.
        • > Wind farm owners get taxpayer help with constructi0n?
          FTFY :
          Wind and nuclear, and coal, and oil ... power plant owners get taxpayer help with constructi0n?

          • If you did the calculation based on $ per MWH generated, you'd see that solar and wind get help many times what any other source has ever seen. Its not even close.
      • by fahrbot-bot ( 874524 ) on Sunday September 20, 2015 @01:22PM (#50561689)

        You can't just "do" something with surplus power on the grid...

        Actually, you can and in Virginia we do. The Bath County Pumped Storage Station [wikipedia.org] uses surplus power (from a nuclear plant) to pump water up into a reservoir to later be used to generate hydro power during high demand.

        Also see: The Inside Story Of The World’s Biggest ‘Battery’ And The Future Of Renewable Energy [thinkprogress.org]

        • by Shoten ( 260439 )

          You can't just "do" something with surplus power on the grid...

          Actually, you can and in Virginia we do. The Bath County Pumped Storage Station [wikipedia.org] uses surplus power (from a nuclear plant) to pump water up into a reservoir to later be used to generate hydro power during high demand.

          Also see: The Inside Story Of The World’s Biggest ‘Battery’ And The Future Of Renewable Energy [thinkprogress.org]

          That's an experiment, not a reasonable solution that exists for widespread use today. Also, good luck finding hydroelectric facilities that can be used that way in Texas...or, for that matter, in most places. The fact that a handful of facilities, scattered around the world, that have experimented with various forms of bulk energy storage does not mean that bulk energy storage is suddenly a widespread option for an area the size of ERCOT's BES region. These are laudable projects that aim to address the t

          • That's an experiment, not a reasonable solution that exists for widespread use today. Also, good luck finding hydroelectric facilities that can be used that way in Texas..

            Like the Wildflower Pump Storage [tomlininfrastructure.com]in Southeast Oklahoma that will

            ... deliver power into three electrical grids: ERCOT (Electric Reliability Council of Texas), SPP (Southwest Power Pool) and MISO (Midcontinent Independent System Operator), providing peak power that will help reduce energy shortfalls as well as ancillary services.

            and the proposed Cedar Creek Pumped Storage Project for Briscoe, Armstrong and Randall counties [law360.com]

            You're correct that these opportunities are limited in Texas, but according to Texas State Energy Conservation Office [state.tx.us]:

            Annually Texas generates approximately 1 million megawatt-hours (MWh) of electricity directly from water resources via 675 MW of hydroelectric power capacity. This hydroelectric generation amounted to only 0.3% of the total electricity generation during 2007, and further development of feasible hydropower resources could result in approximately 4 more million MWh per year.

            But, the above does also note that:

            The use of Texas water resources together with other technologies that can exploit saline gradients between water sources is possible, but limited to several million MWh/yr.

          • That's an experiment, not a reasonable solution that exists for widespread use today.

            It and others have been in operation for DECADES, and it's so large-scale that several percent of US & EU power demand can be supplied by the installed pumped-hydro power stations.

            Just how many years of successful operation, and what percentage of capacity does it need to serve, before you stop calling it "experimental" and "not [...] widespread"? Sounds like you're full of it and just don't like pumped-hydro as a solu

          • What do you think ERCOT did with the power it bought for a negative price?

            Ofc it stored id in pumped storages ...

            No idea why you have so less clue. EVERY grid has about 5% to 10% of its peak power as pumped storages. The storage capacity usually is minimum a quarters day production, but in Germany - if I'm not mistaken - about 2 days (which only shows the amount of water, ofc the plants can not produce enough power to run the country 2 days).

            They are not "experimental" ... they are a fundamental necessary f

        • (*facepalm*)
          That is exactly what your parent said, you need a sink for the extra power.

          • (*facepalm*) That is exactly what your parent said, you need a sink for the extra power.

            He said you can't just do something with the extra power. Sure, Texas may not have reservoirs, but if they were better connected to other grids, they could sell their extra power to localities that can "do something" with it. Also, as I noted in another post, and you replied to, Texas is looking into pumped storage and near-by Oklahoma already has one that supplies ERCOT in Texas.

            • He said you can't just do something with the extra power.
              Yes, that is what he said, and it is plain obvious that he meant: "it needs to be put to some use".

              Texas is looking into pumped storage and near-by Oklahoma already has one that supplies ERCOT in Texas.
              That is plain obvious, too. Every grid has a noticeable amount of pumped storages. Otherwise the grids we have in our days wont work at all.

              Or, what do you think where the excess power of a coal plant goes to, when demand suddenly drops? Into a pumped

              • He said you can't just do something with the extra power. Yes, that is what he said, and it is plain obvious that he meant: "it needs to be put to some use".

                Texas is looking into pumped storage and near-by Oklahoma already has one that supplies ERCOT in Texas. That is plain obvious, too. Every grid has a noticeable amount of pumped storages. ...

                And when *I* mentioned pumped storage, *he* replied:

                That's an experiment, not a reasonable solution that exists for widespread use today. Also, good luck finding hydroelectric facilities that can be used that way in Texas...or, for that matter, in most places.

                So which is it (a) him: "an experiment, not a reasonable solution that exists for widespread use today" or (b) you: "Every grid has a noticeable amount of pumped storages" ? Texas and neighboring states have them, but since you two don't seem to agree, perhaps it isn't as "obvious" as you think.

        • by tomhath ( 637240 )
          The Lewiston Pump-Generating Plant [wikipedia.org] at Niagara Falls is a better example. But in order for that type of system to work you need a very predictable oversupply of generated electricity. Extra capacity a couple of times a year for a few hours won't do it.
          • The Lewiston Pump-Generating Plant [wikipedia.org] at Niagara Falls is a better example. But in order for that type of system to work you need a very predictable oversupply of generated electricity. Extra capacity a couple of times a year for a few hours won't do it.

            Agreed. The one in Virginia is powered using excess from a nuclear plant - pretty predictable :-)

      • Actually, this isn't true at all. Wind farm owners are participants in ERCOT like any other generation facility; if there's too much power on the grid, they are given directives to throttle down, even to zero if necessary.

        What we need is a way to use the excess electricity, or store it.

        Storage may be coming within the next 5 years or so. I know, I know, all battery technology is "five to ten years out", but I've been following Donald Sadoway's liquid metal batteries [mit.edu] for awhile now. They're slowly building bigger and better versions, figuring out the full-scale details before releasing it on the market. They're now very close, with no appreciable problems.

        Usage is another possibility. Nitrogen fixation (via the Haber process)

        • Or, perhaps we could shunt unused power towards liquefying CO2 from the atmosphere and pumping it back into unused oil wells.

          CO2 can not be liquified :D it is one of the rare substances that have no liquid phase and go from gas to ice and ice to gas directly ;D

          • by zenyu ( 248067 )

            I don't know where you got the idea that CO2 doesn't have a liquid phase, but it actually has a pretty standard looking phase diagram. It's triple point is within easy reach of a home experiment if you want to see for yourself.

      • Nothing you've said contradicts the parent AT ALL. Yes ERCOT can tell them to throttle down, so they dramatically lower their prices, into negative territory, to ensure somebody will consume all their output, and they can keep operating, to get those federal dollars.

      • Even a difference of half a cycle (in power, a cycle is 1/60th of a second) is catastrophic.
        That is nonsense. 99% of all electric equipment does not care about the frequency.

        However the whole AC grid is constructed around the idea to keep the frequency stable.

        The reason is: it is far simpler to measure the frequency and increase output when it drops or do the opposite when it increases then to "online real time" measure every consumer and producer on the grid.

        • You're right if you're considering just the end-users, but absolutely, incredibly wrong when you consider the entire grid. When different portions of the grid are out of phase, they start fighting each other- look at it in terms of just Ohms law- when all the voltages are exactly in phase, the difference in voltage between the generators is zero- so because V=I*R, the current between the generators is zero. Add a little bit of phase difference, the instantaneous voltage difference is no longer zero, so curr

          • Ofc, that is true for the grid and its generators.
            However the parent claimed every electric/electronic equipment attached to the grid would be damaged ... which is wrong. The problem is, as you point out, the (resulting) fluctuation in voltage.

            If a single event destroys a lot of the infrastructure, it could be years before the grid is restored.

            Yes, in a 3rd world country *cough*, *cough*.

            • The OP actually did specifically refer to the damage to the 'bulk electric system' which I believe was referring to the grid. No matter. A serious frequency/phase excursion can FUBAR the grid. If you FUBAR the grid of a modern country,that country is pretty much instantly moved to 3rd world status, particularly if the equipment needed to manufacture the necessary parts to repair the system are themselves powered by the grid. Big transformers are not a part that is kept on the shelf in a ready to install sta

          • by bbn ( 172659 )

            Each generator is constantly trying to run a little faster than the grid. This result in a current from the generator. If the generator only matched the grid exactly, there would be no current which means there would be no power generated.

            The grid frequency will in fact change according to load. Look it up. If the grid is overloaded, the frequency drops. This happens because the voltage difference between the generator and the grid is just another way to view the fact that the generator is a bit a head. A b

    • A tiny fraction of the money poured into Oil companies:

      http://www.theguardian.com/env... [theguardian.com]

      https://en.wikipedia.org/wiki/... [wikipedia.org]

      http://www.theatlantic.com/bus... [theatlantic.com]

  • Of course (Score:4, Insightful)

    by rmdingler ( 1955220 ) on Sunday September 20, 2015 @08:42AM (#50560497) Journal
    One of the ongoing challenges with renewable sources of energy is the unpredictable nature of their production.

    There are many storage methods available [wikipedia.org] for this excess energy.

    Seemingly concerned with the "Texas" angle, TFA fails to mention if this is a rare anomaly or worthy of storage development.

    • Re:Of course (Score:4, Informative)

      by Shoten ( 260439 ) on Sunday September 20, 2015 @09:53AM (#50560693)

      One of the ongoing challenges with renewable sources of energy is the unpredictable nature of their production.

      There are many storage methods available [wikipedia.org] for this excess energy.

      Seemingly concerned with the "Texas" angle, TFA fails to mention if this is a rare anomaly or worthy of storage development.

      Coming from a career working in the power industry, I gotta tell ya...that Wikipedia entry is about experimental methods, not things meant to store energy on a bulk scale. Bulk storage is an end goal, but saying that "there are many storage methods available" is like saying we could have gone straight to the moon as soon as Yuri Gagarin got into orbit, or we could go to Mars today. It just isn't true.

      Yes, there are many approaches being experimented with, and some of them are very large facilities. No, none of them work as needed yet.

      • Re: (Score:2, Interesting)

        by Anonymous Coward

        Currently this is true, but the costs on batteries keep going down and as the battery producers ramp up production prices will drop even more. Things are going to get interesting [greenbiz.com] more quickly than many realize:

        In our modeling for both The Economics of Load Defection from April 2015 and its predecessor, "The Economics of Grid Defection" from February 2014, our average battery price in 2015 was $547/kWh. Our models did not assume a price close to $350/kWh until 2022 (the $429/kWh price arrived in our models

      • Coming from a career working in the power industry, I gotta tell ya...that Wikipedia entry is about experimental methods, not things meant to store energy on a bulk scale.
        No, none of them work as needed yet.

        In 2010 the United States had 21.5 GW of pumped storage generating capacity.
        The EU had 38.3 GW net capacity of pumped storage , representing 5% of total net electrical capacity in the EU.
        Japan had 25.5 GW net capacity.
        https://en.wikipedia.org/wiki/... [wikipedia.org]

        Sounds like 'bulk scale' to me...

      • In addition to many methods that are still experimental today, the article lists pumped (water) storage, which is in widespread use today (127 GW capacity installed). Single facilities can store multiple GWh at 70% efficiency.

      • by Lennie ( 16154 )

        Doesn't matter how we slice or dice it, storage is where the excitement should be.

        And Germany, like before with solar (and wind), is putting their money behind it to develop more and better systems for it.

        See the kinds of prediction by the Deutsche Bank are making for 2017 for solar even:

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

        I think they are right as long as Swanson's law for Solar and keeps working. Batteries are also still improving, if slowly.

        Their predictions, like 2017, seem kind of early. But let's say it'

  • Not news (Score:5, Informative)

    by pocketbookvote ( 1541431 ) on Sunday September 20, 2015 @10:32AM (#50560831)
    Negative prices have persisted in Texas and elsewhere for the past decade; this is not news. It is a function of the tax credit, but also a lack of transmission. When transmission is not available from wind resource areas, the prices will be negative there (and higher on the other end), reflecting the fact that wind has to back down because it can't go anywhere. There are also instances where there is simply more power than there is demand over an entire area, but this not as common; that scenario is actually a bigger problem in California due to the buildout of solar (for which there is no production tax credit, notably). Negative pricing was much worse in Texas a few years ago before they built a backbone transmission system to get wind from West Texas to load in the east. There is no doubt that the spot price of energy on average is lowered by wind; utilities nationwide are signing contracts at $20/MWh or less, well below today's average spot price, fixed for 20+ years. Interesting aside - even before there was much wind, prices in the Pacific Northwest would typically go negative for a few hours in the spring when coal needed to be paid to back down to accommodate spring runoff through the hydro system.
    • reflecting the fact that wind has to back down because it can't go anywhere.
      That is a misconception.
      The fact that there is a price indicates that there is trade and hence the energy goes somewhere.

  • by gurps_npc ( 621217 ) on Sunday September 20, 2015 @11:49AM (#50561187) Homepage
    That is how the free market is supposed to work. Anyone that can come up with an effective electrical storage company can make a ton of money with spot negative prices. Even if negative prices vanish, they can still make money with a large enough spread.

    If storage has even an 50% loss rate, then daily price variation should be limited to 50% because otherwise storage batteries would make a profit.

    The trick is to create a battery efficient and cheap enough to reliably make money on daily price variations.

    • That is how the free market is supposed to work.

      "supposed" is the operative word here because "free market" is a fiction

    • by Solandri ( 704621 ) on Sunday September 20, 2015 @01:37PM (#50561767)

      If storage has even an 50% loss rate, then daily price variation should be limited to 50% because otherwise storage batteries would make a profit.

      No, that in itself isn't enough for storage batteries to be profitable. Take lead-acid batteries for example. They're a century-old technology whose primary drawback (weight) isn't a factor for storage applications. A deep-cycle lead-acid battery will cost you about $1 per Ah. At 12 V, that's $1 per 12 Watt-hours of capacity, or $83.33 per kWh of capacity.

      The average residential price (the more expensive) of electricity in the U.S. is $0.12/kWh. If the price swing between day and night is $0.12/kWh ($0.18 at peak, $0.06 at night), then it will take you $83.33/$0.12 = 694 cycles to recoup the cost of the batteries and actually start to make money.

      "Great! So you'll start making money after 2 years!" No, these batteries typically only last 150-300 cycles. Deep cycling is very stressful to the chemistry, and the cells rapidly begin to lose capacity beyond that many cycles. So it'll die long before you reach your break-even point. If you figure it lasts 300 cycles, the daily price differential in electricity price between day and night needs to be $0.278 per kWh before the battery becomes economical. If it only lasts 150 cycles, the price differential needs to be $0.556 per kWh. And I haven't even factored in charge/discharge efficiency.

      This is why batteries are used almost exclusively for mobile applications - where it's impractical to draw power straight from the grid. Essentially you're paying dozens of dollars to carry around a few cents worth of electricity. Trying to turn that around and use batteries to release electricity back to the grid is adding a huge expense for very little benefit. It's almost always more practical to just scale electricity production up or down to meet demand, than try to time-shift it with batteries.

      • Just generate hydrogen and sell it to the chemical industry. (And pure oxygen, while you're at it. It's also worth something.)
        • "Just"? Hydrogen is very inefficient to compress and not very useful uncompressed. If you react it to store it, then you have thermal losses going both directions and because hydrogen has an atomic weight of 1, anything you mix it with for storage purposes will have a relatively low energy density. Over time it turns even the hardest steels brittle and is a pain to handle. And then there is the fact that it is an explosion hazard. There is no "Just" when it comes to hydrogen.
      • Lead-acid batteries work reasonably well for homes, but aren't a good option for grid-scale installations. Try the numbers with a Redox Flow Battery. The operating costs (after up-front installation costs) are more favorable:

        http://cleantechnica.com/2014/... [cleantechnica.com]

    • That is how the free market is supposed to work.

      There's nothing "free market" about it. Negative wind prices only happen because of federal subsidies of $24/MWH. That why producers are willing to pay $8/MWH for someone to take it. A free-market price of about $16/MWH is the best you could hope for.

    • In principle true, but storage alone is not enough, you need the grid, too.

      E.g. if own a nice spot for a pumped storage plant, but there is only a low voltage connection to the grid, we need a better grid connection and of course that includes information technology when to draw power from the grid and how much and when to idle and when to generate power.

      Also the grid operators need to know my capacity, both ways, all the time.

      Pumped storage by the way has no 50% loss rate, it is about 81% effective, in som

    • If storage has even an 50% loss rate, then daily price variation should be limited to 50% because otherwise storage batteries would make a profit.

      50% loss rate energy storage is easy and it exists. It is simply a hydro electric dam with pumps to pump water upstream behind the dam. I have read about using such a scheme to even out the difference between peak and base load in a grid. I read about one such project back in 1980s [energystor...change.org]

      . The Chief Minister who inaugurated the project was a ex-movie actor, who completely misunderstood the project. He said it would generate power when the water flowed down, then they will pump the water back up and make energy ag

    • No free market has ever existed. Not even the most primitive tribes have markets that are free of taboos, rules, some form of taxation or regulations. The concept of a free market exists to fool people who really don't think things out. Tell me that some markets are freer than others and I will tell you my sister is a little bit pregnant. It makes no sense at all. She either is pregnant or she is not just as you are free or not.
    • by tomhath ( 637240 )

      Anyone that can come up with an effective electrical storage company can make a ton of money with spot negative prices

      According to the article this is the first time it actually happened, and the circumstances were very unusual. So don't spend too much of your own money on electricity storage just yet.

  • The US uses million and millions of barrels of oil every day. If we replaced that with electricity, and wanted to store even a few minutes worth of a small section of a states energy supply either we have two options: Store it in a medium with about the same energy density of gasoline or crude oil. - We are talking about taking up the area of hundreds of thousands of cubic meters for even just a small section of a state. Store it in some yet undiscovered way that is orders of magnitude smaller. - You just c
  • We've been told for years that we need to subsidize wind power so that there will be investment in wind power development so that it can compete on the open market with coal. It looks like we've reached that goal. Wind power can produce up to 40% of the power in Texas and that sounds like a success to me. I believe that wind can now compete on its own merits now.

    For those that will inevitably point out that coal gets subsidies too, I say those need to go away too. No more energy subsidies.

Doubt is not a pleasant condition, but certainty is absurd. - Voltaire

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