In Oregon, Wind Power Surges Disrupting Grid 506
cpm99352 writes "The Oregonian reports gusts of wind cause synchronized power surges, more than the transmission lines can handle. Windmill farms are ordered to fan their blades, despite tremendous demand for 'green' power from California."
Re:Store in a water tower (Score:4, Informative)
Dutch wind energy is currently being stored in Norwegian lakes (because here it's flat, and they have mountain lakes). Apparently the advantage was worth laying the worlds longest underwater power line between nations.
With my emphasis on the quote above, I reckon that if the Oregon->California electrical lines would be of the same quality, then we wouldn't see TFA on /., would we?
But taking this idea a step further for local power generation: Why convert to electricity in the first place? If you pump water to a higher place [etc.]
Now, as a Dutch you should now that the Dutch windmills were used initially to pump water out, not to generate the electricity.
Where is this relevant? If your main purpose is to generate electricity, then each step of transforming energy in different forms will cost you at the bottom line (efficiency goes down). I'm not saying that transforming wind (kinetic) energy in water accumulation (potential energy) is stupid if you have excess of wind energy But if you don't have excess, then direct transformation into electric energy will offer you the best return.
Re:Store in a water tower (Score:5, Informative)
As for the 'as a Dutch you should know'; when you quote someone it helps to also read the part you replaced with '[etc.]' since I already noted that windmills were created originally to pump water...
Re:From TFA, wind is fine. (Score:4, Informative)
I could probably quote myself from the comment I made about 6-12 months ago when someone posted an article about the US wanting to buy more green power. But I wont bother to search for the article, so I'll just say:
THIS IS the problem with the currently renewable energy sources. We do not have control over their output. When they produce too little we need to augment, when they procude too much, we need to siphon the excess. The higher the percentage of renewable energy is being used, the more these extremes will vary.
So putting out an economic incetive (like the energy credit in the article), means that societys requirements and needs will be countered by politics (however well intended) when they're told they're overperforming, because the energy shouldn't go to waste.
The exact same thing happens here (where we can't rely on solar during the day, due to heavy clouding during wintertime where powerconsumption is highest), the windmills overproduce heavily at night, where the cost of energy can actually drop to NEGATIVE (yes, you get paid to buy power at certain times of the night on rare occasions in northern Europe). One of the ways to counter this, is actually by tailoring consumption. So if you have a smart house, and an electric car. NOW is the time your batteries will start charging. This is also the idea behind the "better place" http://www.betterplace.com/ [betterplace.com] Weather you store in a chemical or natural battery (like a lake on the other side of a dam), or you turn down other sources of power, we WILL need a way to regulate that doesn't involve cutting production of the cleanest powersources.
I admit, there WILL be a cost to the energy infrastructure in the future (or as the article suggest, NOW). And as the energy market goes global, we're not just talking sales from state to state. But that investment should have been obvious from the initial planning of the site. If you can procude 400MW, it's no good if the infrastructure is only made to handle a third of that. That'd be like building a 1 lane freeway.
Re:Stop putting it on the grid! (Score:3, Informative)
One thing that you won't be able to predict is when the tank/lake will be so full you can't pump in it any more. I guess I'm trying to say that: what is unpredictable will stay unpredictable (no matter how many buffers you use to cushion against values you cannot handle).
How is that unpredictable? You should always know the current water level. If you know the mean and maximum pump rates as well, then you can set a computer to fan the blades on the windmills, in turn generating less electricity, when you get near the limit. If you reach the maximum very often you should think about adding a second reservoir.
It can be done - Spain example (Score:4, Informative)
Distributed storage (Score:2, Informative)
In the not-so-distant future, we may see a large number of electric vehicles on the road, with increasing policy support. The batteries in these vehicles could provide a very good distributed storage solution through an intelligent charging infrastructure.
One of the biggest arguments against wind power has been intermittency and the inability to tailor demand to supply volatility. An on-site storage can provide stability of output from the wind farm to the grid, but the options are either too ecologically-damaging (normal lead-acid batteries), or too radical (underground compressed air storage), or too debatable (hydrogen, in terms of efficiency of electrolysis, transport / storage and reconversion) and in all cases too expensive and unproven. A high capital cost of the wind farm itself ($1.5 - 1.8 mUSD / MW) and low capacity utilisation factors (27% - 35% at Class I windy sites) mean that given the current utility offtake rates in the US make the project barely viable by itself, and no developer would want to add a hugely expensive backup facility.
On the other hand, the anti-EV lobby opposes the claim of a reduced carbon footprint by a switchover to electric, by calculating the emissions related to power generation, whether through coal or gas. In this case, it would make imminent sense to use renewable sources to generate electricity for charging EV batteries. This still does not solve the issue of a limited range, which is the chief criticism of EVs.
Companies like Better Place (http://www.betterplace.com) have started lobbying hard, tying up with governments in Denmark, Israel, Australia, and local bodies in places such as San Francisco and taxis in Tokyo, to establish an EV-charging and battery swapping network to provide an innovative and seemingly practical solution to the range problem. The network they are proposing to build will keep talking to the car (such as the Nissan Leaf) to keep track of the charging status, the vehicle's position and availability of nearby swapping stations.
Further, in order to address the issue of peak demand, they also propose to charge intelligently, especially during non-peak hours. This can be done for both the battery in the car and the stock in the swapping station. Better Place also talks of buying power from renewable sources to keep the carbon footprint low.
In India, the wind power producer need not be a dedicated utility. Power can be generated by an industrial unit, fed into the grid, and a credit in terms of kWh supplied is available in the industrial unit's power bill, with banking facilities to help adjust excess generation and excess consumption. In some places, time of day metering and credit mechanism is also used to reward generation during peak hours. Similarly, a wind farm can sell power to an unrelated industrial unit too. Such a system could be introduced in the US and elsewhere.
Continued...
Re:Store in a water tower (Score:5, Informative)
Re:Isn't fanning the blades the problem? (Score:3, Informative)
hydrogen is a joke (Score:5, Informative)
people please stop talking about hydrogen
it wastes too much energy in electrolysis and then burning. plus its a nightmare to store and handle. there's far more efficient energy storage mediums that are far easier to manage
i wish people would just forget about hydrogen, but it seems to have entered the public conscience and will be a long time in banishing from consideration. hydrogen is not a serious green energy contender, and never will be
its too wasteful to convert to, and then convert back from, and too messy to handle. please understand these simple obvious facts that make hydrogen a complete waste of your time
Re:From TFA, wind is fine. (Score:5, Informative)
THIS IS the problem with the currently renewable energy sources. We do not have control over their output.
No : the major source of renewable energy today is hydroelectric dams, whose output can be nearly 100% controlled.
Re:Stop putting it on the grid! (Score:4, Informative)
The word is 'feather', people. You feather the blades.
Re:Isn't fanning the blades the problem? (Score:4, Informative)
As another poster in this article noted the term is "feather" the blades, not "fan" the blades.
Re:Heard of power demand spikes? (Score:2, Informative)
As I said, consumer demand spikes are generally predictable, so that generating capacity can be warmed up in advance. When consumers are being unpredictable, they tend to cancel out.
I have never said that renewables cannot generate enough electricity. However, in order to produce a reliable supply, renewables must be backed up by storage sufficient to cover the troughs in renewable supply by storing energy from the peaks. If you add in the entirely necessary cost for this storage, the total bill becomes much greater. We should still do it, but we must recognize the extra cost.
Wind power is particularly bad in this respect: Its peak-to-trough ratio is very high, very unpredictable, and troughs can be very long. The latest solar generators, by using thermal instead of photoelectric conversion, are able to store heat overnight in baths of molten salt and flatten out the day/night variation. These provide a much more tractable form of renewable energy.
Re:Much ado about nothing (Score:3, Informative)
The gist of it is that Denmark exports almost all of the wind energy they generate to neighbouring countries, because most of the time the power generated is in excess of the demand.
Denmark is a very small country with lots of wind. I'd guess that they are doing this on purpose, simply producing power as an export product (probably a bit like Oregon in this story).
In Belgium, currently about 55% of our electricity is generated by nuclear plants. The problem? About 55% of the time (from 21h-6h on weekdays and all day on weekends), the power generated is in excess of demand and simply reducing the output of nuclear plants at night and on weekends is apparently not economically feasible (I can't imagine why they wouldn't do it if it were, it's not like Suez/Electrabel are corporations with a bleeding heart).
As a result, electricity is cheaper at night and on weekends, and virtually all of our motorways are lighted at night. Sure, it's nice to have all that light (except if you want to look at the night sky), and in the future this will also be useful for recharging electric cars, but the constant power generation by nuclear plants is not without its problems either.
Granted, that paper is several years old, but it still demonstrates the randomness of wind-based energy-generation pretty well.
It's not really random, but it definitely is variable. What is however generally more important is the predictability of the generation so you can adapt other means of production. And those prediction models get more accurate every year. In fact, the more wind mills are put into operation, the more accurate the models get because you get more measurement locations.
In Belgium, if the wind comes from the East, then based on measurements in Germany they can quite accurately predict the output of Belgian wind farms several hours in advance. This allows them to constantly adjust the power production of other plants (in Belgium it's mainly natural gas, often combined with burning garbage because we don't have room for huge landfills) and keep the grid at a more or less constant load.
Wind can never be used for base load energy generation without some kind of (expensive and impractical) energy-storing gimmicks, so instead of that how about just building a few comparatively cheap nuclear reactors and being set for decades? Perhaps at that point wind energy will be more feasible
One problem is that nuclear does not play nice together with wind/solar power generation because of its inflexibility in terms of output. It does not make sense to put lots of wind mills or solar panels on a grid that is almost completely fed by nuclear plants, because their production patterns cannot be used to complement each other. As a result, you get less investment in wind/solar power research, which is sort of a vicious circle.
It's true that you do need a base load guarantee and that localised wind production can in no way guarantee that. One of the keywords is locally though, because if you look at the wind over large areas of land (and/or water), the variations in total available wind power are reduced quite a bit (lots of nice graphs [wind-energ...-facts.org]).
There's no silver bullet, but I think it's incorrect to paint the picture as if wind power is completely unsuited compared to nuclear power. Both have problems in terms of matching the demand and keeping an even grid load.
Re:From TFA, wind is fine. (Score:5, Informative)
Solar thermal also does not face this problem. It has very, very predictable peak loads and any excess can be stored directly as heat in an underground reservoir of molten salt or heated oil for nighttime use, or you can simply turn a valve and direct the steam away from the traditional turbines.
Re:New efficient energy storage with hydrogen (Score:5, Informative)
The site you link claims 97%, not 98%.
And that's just storage. In practice, you get 70% efficiency for making the hydrogen from water and around 50% from a fuel cell turning it back into electricity. Inverter losses are typically another 2-3% (98% efficiency) on both ends.
0.98 * 0.70 * 0.97 * 0.50 * 0.98 = 22.6% overall.
Pumped water storage is between 70% to 85% efficient overall.
=Smidge=
In Texas, the Opposite Problem (Score:5, Informative)
Re:Store in a water tower (Score:3, Informative)
Re:Much ado about nothing (Score:3, Informative)
Modern wind turbines don't run in phase with the grid, they convert with power electronics. This means that they are a great stabilizing factor on the grid in the short term, especially if the load needs power factor correction.
Older wind turbines were indeed troublesome for the grid because it is difficult to keep something powered by the wind rotating at a completely steady speed. Luckily this is no longer necessary.
Anyway, two coal fired blocks are supposed to be closed in Denmark this year according to this article [ing.dk]. They have not been replaced by new coal-fired capacity (and that wouldn't make sense anyway, as they are fairly modern and quite efficient).
Re:Store in a water tower (Score:5, Informative)
Local energy storage with hydrogen, 98% efficiency? HA!
Round trip, it's closer to 50% using ceramic fuel cells, and the capital costs are absurd compared to other options relative to power provided (and only moderate relative to energy stored).
The two most cost-effective storage methods at this point in time are batteries and pumped hydro. In most areas, pumped hydro is cheaper. Pumped hydro does *not* require continuous incoming water (beyond what is lost to evaporation), and the water pumped need not be freshwater (it could be a mining pond contaminated with nuclear waste for all they care). As far as batteries go, there are several techs that are all reasonable and depend on what you need -- lead acid and various flow batteries (most famously, vanadium redox) being the prime examples.
Also, not all energy storage is for *supply* buffering. Worldwide, the overwhelming majority of it is for *demand* buffering. And not all of the demand buffering is even due to power plant limitations; some is due to line limitations. For example, one of the Rattlesnake lines out in Utah has a vanadium redox buffer for voltage support out in Castle Valley. The area is sensitive, so they have trouble building new lines, and a lot of the places that need power are rather isolated, so they can't justify increasing the capacity of their existing lines. So what they did was build a big buffer in the middle of it that stores power at night and releases it during the day.
Energy storage does add a cost, but it's not prohibitive. It's generally a couple cents per kilowatt hour, give or take.
Produce Energy Intensive Products (Score:3, Informative)
I think another solution to using excess capacity is to produce energy intensive products. For example ammonia is like the second or third most produced chemical because the fertilizer industry buys mass quantities of it. You could think of ammonia as a nifty way of storing hydrogen because it's very easy to compress it into a liquid. For a windmill farm you would probably want to start by eletrolyzing water into O2 & H2. Then take the H2 and Air and produce your ammonia. A windmill farm might build a small mostly automated ammonia plant on site that can be switched on when the wind is blowing hard and be able to store the product for later transportation by truck.
BTM
"disrupting grid" is wholly inaccurate (Score:2, Informative)
Partly due to the title of the original post I think a lot of people are misinterpreting the issue here.
Sudden surges in wind capacity are not "disrupting the grid." nothing is broken, there are no alarms at the control station. What's happening is simply that during brief bouts of strong wind, the wind turbines are generating so much electricity that the Pacific Intertie (which carries power from Oregon to California) cannot carry it all. Power schedulers are feathering the blades of wind turbines, meaning the blades are being turned to parallel with the wind so that the turbines generate less electricity.
What does this really mean? To be honest, it's not a big deal. Frankly, I think it's cool - at times we're generating so much power with our wind capacity that it's exceeding the capabilities of the Pacific Intertie, one of the United State's largest long-distance direct-current transmission routes. From the perspective of the Bonneville Power Administration and wind capacity owners in the Pacific Northwest this is annoying, because feathering wind turbines is like opening the spillways on dams - they're effectively letting power flow by uncaptured, which means they can't sell it. If the Pacific Intertie were expanded, they could sell all of the power even during large surges, which means more money for them.
Really, though, nothing is wrong. We're saturating the intertie, which is a good thing, because that means more power for power-hungry Los Angeles, and more money for money-hungry wind turbine operators. All we need to do now is advance storage technologies (Bloom Boxes, anyone?) so that we can saturate the intertie more often.
As a note, I'm very interested in bloom boxes for storage of power from unreliable sources. The efficiency numbers Bloom Energy has published are incredibly promising.