China To Use Curtailed Wind Power To Replace Coal-Fired Heating

May 1st, 2013 by Nicholas Brown

In China, coal is very heavily used to generate electricity. It is also used to heat buildings. The Chinese have experimented with the use of curtailed wind energy to provide heat, and they now want to scale it up.

Image Credit: Wind Farm via Shutterstock

Jilin Province has one of the highest curtailment rates. There, there is relatively low electricity demand at night, but high wind speeds — and hence, high wind power generation.

Curtailed wind power is wind power that was not put to use, that essentially goes to waste. The amount of wasted wind power has been increasing substantially in China. The amount of curtailed wind power in 2012 was 20,000 GWh, approximately twice what it was in 2011.

This resulted in wind farms being allowed to generate electricity for only 1,420 hours in 2012, “much lower than the industry-adopted economic minimum of 1,900 hours,” Wanqing Zhou of the China Program at Worldwatch Institute notes.

That is enough to power 6.66 million homes for one hour, 277,000 homes for a day, or 761 homes for an entire year!

It is time to put that electricity to use.

This wind-to-heat concept provides multiple benefits:

Coal-fueled heaters pollute the air because they burn coal. Burning coal produces the toxic substances (in gas form) carbon monoxide, sulfur dioxide, nitrogen oxides, mercury, arsenic, lead, and carbon dioxide (which is not toxic, but is a greenhouse gas which causes global warming). Using wind power to provide heating via electric heaters can partially replace these coal-fired heaters, reducing all of these emissions.
The use of curtailed wind power to heat instead of coal is good for China’s economy because it would have otherwise been wasted. It reduces coal expenditures by reducing coal requirements.
This is good for the wind industry because companies can sell the wind power that would have been curtailed, and wind power is generally cheap (less than 10 cents per kWh). Curtailed wind power is a loss of potential revenue, but it doesn’t actually incur expenses.

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Tags: Alternatives to curtailing wind power, China, China curtailed wind power, china wind energy, china wind power, china wind power to heat, China wind to heat, Curtailed wind power, heating with wind turbines, Putting surplus wind energy to use, Putting wasted wind power to use, Wind powered heating, Wind-to-heat

About the Author

Nicholas Brown writes on CleanTechnica, Gas2, Kleef&Co, and Green Building Elements. He has a keen interest in physics-intensive topics such as electricity generation, refrigeration and air conditioning technology, energy storage, and geography. His website is: Kompulsa.com.

Ronald Brakels

In the past China subsidised building wind power capacity. This subsidy did not depend on whether or not there was adequate transmission capacity to handle it. They have since changed their policy, but there is still an overhang from it.
arne-nl

China is the biggest wind market in the world, but still still has a relatively small amount of wind installed. Alas, it is not wind producing more than consumption on a national level!

As far as I can judge this, the curtailment is due to insufficient grid capacity (transporting wind power out of areas of high wind penetration and low population density) and/or too much baseload that can not be regulated.

20 TWh is a lot, probably in the order of 15% of total wind production in China.

The heating value of coal is ~8 MWh/ton. 20 million MWh equals around 2.5 million tons of coal, less than 0.1% of annual coal consumption. So it helps, but not a lot. That’s why I used a 1:1 ratio for kWh electric versus kWh coal.

Some commenters have suggested heat pumps, but I am not sure many Chinese can pay for this expensive technology. It wlll probably be used in simple resistive heaters.
http://profiles.google.com/vandammes James Van Damme

Heat pumps and smart meters.
Dave2020

It’s easy for anyone to say with the benefit of hindsight, but the ‘powers that be’ should have seen this coming before the end of the last century.

Everyone’s been too focussed on – “What do we do when there’s a lull in renewable generation?” and not given enough thought to – “What happens when surplus power swamps the grid?”

Whether the problem manifests itself when there’s inadequate transmission capacity or through a mismatch with demand, by far the best solution is to store renewable energy at source, because that reduces peak generation AND keeps the generators going when the wind drops. (or the tide turns)

Installing new systems in order to use the ‘wrong-time’ surplus, is a very slow and expensive business. e.g. switching domestic heating to electricity.
- Bob_Wallace
  
  Dave, it’s sometimes cheaper to curtail wind/solar than to transmit or store it.
  
  It’s sometimes cheaper to overbuild capacity and throw away/curtail some of the output than to build storage.
  
  If we sometime overbuild then someone may come along with a clever use for that surplus. In this case, the Chinese have found one. We might take their lead and look for places where we could use extra off-peak wind generation, turn it into heat, and displace fossil fuel heating in industrial settings.
  - arne-nl
    
    Actually, overbuilding is very common for fossil power plants. Whenever they are shut down because of low demand, that is a form of curtailment too.
    - Bob_Wallace
      
      True, we have natural gas plants which run only a few hours per year. In the Pacific Northwest, with its excellent wind and hydro, coal plants are closed for months.
      
      Recently we brought a moth-balled NG plant back on line after a few years of non-use in order to fill in for the San Onofre nuclear reactors which went off line.
    - Dave2020
      
      How do you make money out of idle assets?
      
      The UK government wants private money to build up to 26GW of new gas generation (largely as ‘back-up’ for when the ‘wind stops blowing’!), but investors break out in a cold sweat at the thought of their gas plant only earning money for “a few hours per year”. The load factor for the entire fleet may drop to 20%, in the not too distant future. That’s worse than wind!!
      
      Under a ‘capacity market’ arrangement the price of electricity could be £10,000 per MWh. Investors want a guarantee that consumers will foot the bill to sustain their profits. Same goes for nuclear – guaranteed prices tied to inflation for 40 years – “or we won’t build it”. This is the ‘market’ solution? No, it’s the lunatics taking over the asylum.
      
      https://www.gov.uk/government/policies/maintaining-uk-energy-security–2/supporting-pages/electricity-market-reform
  - Dave2020
    
    I don’t disagree – never have. We just need to choose the best option for the circumstances at the time, but we could usefully employ a little foresight and plan decades ahead, which the ‘free’ market is bloody useless at. Add to that the power and influence of the dying fossil fuel industries and the planet’s ecosystems (we) have a big problem. Overbuild is only cheaper in the short term.
    
    Surplus PV output could easily be put to good use on-grid and storage only really makes sense to time-shift off-grid, and yet the Germans have tied their incentive to grid-connected storage. Can’t figure that out!
    
    “look for places where we could use extra off-peak wind generation, turn it into heat, and displace fossil fuel heating in industrial settings.”
    
    Naturally – that may be the ‘low-hanging fruit’ approach, but it’s not always the most cost-effective option long term and the way we’re heading, wind power peaks in future will be huge. We are going to need a very large capacity of the most viable energy storage we can devise, and that HAS to be before-generator, NOT after generation. The sooner the better.
    
    “this storage system would dovetail well with (floating wind turbines), Hodder says.” The two ‘halves’ are 400m of deep ocean apart – some dovetail!!
    http://web.mit.edu/newsoffice/2013/wind-power-even-without-the-wind-0425.html
    
    “The researchers estimate that an offshore wind farm paired with such storage spheres would use an amount of concrete comparable to that used to build the Hoover Dam — but would also supply a comparable amount of power.” Sloppy argument – comparable on GW maybe, but not on GWh!
    
    Would the Hoover dam have been built by private investors? How do their design lives compare, and their O&M costs?
    
    The steel and concrete used to build my storage design is, in part at least, the same material that’s used to build the turbine support structure. Makes sense to me!
    
    The American approach to infrastructure build can be an unmitigated disaster. (think bridges) Sorry, in the final analysis, it all boils down to political ideology.
    
    In the UK, the Forth Rail Bridge is an icon, still going strong after 125 years. The road bridge nearby, built in 1964, requires expensive remedial work and faces weight restrictions. You pays yer money . . . .
    http://www.bbc.co.uk/news/uk-scotland-edinburgh-east-fife-21522376
    - Bob_Wallace
      
      US political realities are different now than they were when the US did the big infrastructure jobs like the Hoover Dam, TVA, interstate highways, ….
      
      As for your storage idea, it isn’t going to get built by posting about it on the internet. If you really believe in it you’re going to have to do the hard work of finding enough money to build a demonstration and produce data.
      - Dave2020
        
        Hi Bob,
        
        Sure – political realities have changed globally – that’s one problem.
        
        My belief is irrelevant, and no amount of “hard work” on my part will achieve anything. I first have to find someone who is financially and intellectually capable of doing that work. That’s another hurdle to overcome.
        
        One insurmountable barrier outweighs all others. International intellectual property law deprives me of my IP rights. (human rights, that is)
        
        MIT applied for a patent on their storage Sphere. That process represents a liability of perhaps a quarter million dollars. Only people who can afford to lose that kind of money can play the game. That rules me out.
        
        I adopt a three-pronged strategy – political, commercial and philosophical chats on the net to refine the ideas and weed out any flaws in my argument.
        
        Eleven years of lobbying government (with the support of my MP) hasn’t influenced policy decisions in areas such as Innovation Strategy.
        
        I am currently in correspondence with a new company that claims to have billions of pounds of investment lined up to build their tidal power scheme. I expect they’ll treat this disruptive technology the same way that commercial concerns have in the past – chuck it in the bin without exercising their mental faculties. (not invented here, etc. etc.)
        
        These internet exchanges are the only fun part. Without them I’d lose all faith in the human spirit. Meanwhile, I can put my meagre funds to good use converting my place to low carbon power, starting by stripping out the gas central heating. That’s more rewarding.
        
        ‘The Engineer’ deregistered me. Some people want to curtail my right to free speech as well, it seems.
      - Bob_Wallace
        
        Filing a patent in the US costs only a few thousand dollars. Nothing even remotely like a quarter million dollars.
        
        So far you haven’t convinced anyone to do your hard work for you. Have you considered the possibility that others simply don’t find your idea worthwhile?
        
        Perhaps “The Engineer” got tired of your posts. I can imagine that happening. I’ve seen it happen with people who keep posting about how they have “the answer” yet do nothing to demonstrate that their idea works. And especially when others point out likely problems with their ideas which are simply waved away….
      - Dave2020
        
        Filing for a patent in one country only establishes your priority date. The only protection for your IP is to have the patent examined and granted in each jurisdiction. As I said – a liability easily running into six figures for EVERY novel step in your design. Engineering of such complexity could have dozens of patents.
        
        I’ve never “waved away” any “problems”. I welcome these comments, but they do have to have some merit.
      - Bob_Wallace
        
        If you have a great idea getting it patented in a single large country such as the US would assure you all the wealth you could ever want.
        
        Where’s your proof that vertical wind turbines work? The wind industry hasn’t found that they do.
        
        Where’s your math on energy losses in your mechanical system? That’s fairly simple engineering.
        
        Where’s your math on energy loss via heat during air compression? Again, not rocket science.
        
        Where’s your math on the cost of storing in your system vs. storing by other methods? Unless you’ve penciled out the costs you’ve got nothing.
        
        Have you dealt with the basic design issues which a financing agency would want to see before loaning seed money? Or are you at the “I’ve got an idea. How about you make it work and make me rich.” stage.
        
        Is the decision that “some problems” have no merit made simply on the fact that they challenge your idea?
        
        Actually I don’t see that you have anything patent-able. Your idea is to attach a shaft to a wind turbine and use that to drive a compressor in order to store wind away as compressed air. Then use the compressed air to drive a turbine when the electricity is wanted.
        
        That’s not a new nor unique idea. There was a company (in Texas, I think) that was going to do this on land, storing the compressed air in a cavern.
        
        Actually they may have installed the compressor at the turbine level which would reduce friction losses.
      - Dave2020
        
        I don’t need any more wealth than I already have and a company wouldn’t see much value in patent protection in one country, or even the whole EU. An international market doesn’t work that way.
        
        More competent engineers than I have designed VAWTs that “work”. It’s plain common sense that they would be the better choice for floating installations.
        
        Why would I need any math on CAES? My design pumps water!!!
        
        MIT did the math on a water powered turbine driven from stored power. Are they pulling the wool over your eyes?
        
        My only viable approach is – “I have these ideas which need to be developed. If you can do the evaluation, you can claim the IPR yourself.” What’s wrong with that? Why do you assume I want to get rich off my IP? Altruism works for me.
        
        The objections that have no merit are the ones that are based on misunderstanding the facts that I’ve already spelt out, such as Variable Displacement Water Pump.
        
        Where did you get “compressed air” from?
        
        You don’t ‘believe’ I can design a wave energy converter to stabilise a floating turbine? And you don’t ‘see’ that the running costs of before-generator systems must be lower than after generator storage?! Exactly what I said: People dismiss ideas without even thinking about it.
      - Bob_Wallace
        
        If you’ve got all the wealth you want then quit whining about the cost of patents. Open source whatever you think might be patentable and let someone make something out of your idea if there’s anything to it.
        
        As for your claim that you don’t wave away criticisms, I’ve pointed out to you more than once that VAWTs have not proven to be equal or superior to HAWTs. Check all the wind farms you wish and see if you can find any.
        
        Common sense tells us that wind is better away from the water’s surface. That’s common sense based on data.
        
        Go do the hard work Dave. Come back when you have something other than a concept.
        
        People get tired of your unfounded claims. I know that I certainly am.
      - Dave2020
        
        Putting an idea in the public domain precludes any grant of patent. Your silly suggestion would destroy its commercial value. Who’s going to invest money in that?
        
        So, you don’t like to see the reigning paradigm threatened? I don’t dismiss what you say about the lack of VAWTs – I simply link to expert opinion that doesn’t share your irrational antipathy. That’s how innovation is developed:-
        http://www.onlinetes.com/wind-sail-type-vertical-axis-wind-turbines-111011.aspx
        
        Do you think 100 slow-speed, direct-drive generators with upwards of 50 magnetic poles and a diameter of more than 7 meters will give a lower LCOE than half a dozen bog-standard 100MW generators, driven by water turbines? Seems unlikely.
        
        “The greatest challenge for floating wind technology is the reduction of the Capex impact of building, transporting and installing the necessarily extremely large steel or concrete hull structures.” – ‘UK Offshore Wind Market Study’. For VAWT designs, with a low CofG the hulls could be less massive.
        
        If energy storage is an integral part of those hulls it’s bound to improve the LCOE, but I can’t do the math. So what? All designs start life as concepts!!
        
        It would help if you’d read what I’ve written and checked the links. (with an open mind)
        
        The wind gradient above 30m doesn’t trouble VAWTs, but it puts extra stress on HAWTs. That may not be common sense, but better engineers than I have done the numbers.
      - Bob_Wallace
        
        If your idea had any value then companies would build your concept and make money. A patent would not be relevant.
        
        You linked page does nothing to address the issue of whether VAWTs can match HAWTs. It’s basically more handwaving.
        
        “Seems unlikely” is not data. It’s pure speculation.
        
        You admit you can’t do the math. You admit you can’t get anyone to believe in your dream. You admit that at least one engineering site has told you to go away and stop bothering them.
        
        Dave, you’re blowing smoke.
      - Dave2020
        
        Try telling Sir James Dyson that a patent is not relevant to the value of an idea. Tell him to stop “whining” about the (anti-competitive) injustice of the law. My position mirrors his exactly. Money makes ALL the difference and possession is nine-tenths of the law. That’s business reality and I have to live in the real world.
        
        http://ecogeneration.com.au/news/shaking_up_offshore_wind/075441/
        “Preliminary Nénuphar analysis suggests that their VAWT will lead to a high energy yield, and have lower investment and operating costs.” That can’t be credible either – Bob says it’s just hand-waving.
        
        Here’s some actual (no storage) operational data for you Bob:-
        http://www.wind-energy-the-facts.org/de/part-3-economics-of-wind-power/chapter-2-offshore-developments/the-cost-of-energy-generated-by-offshore-wind-power.html
        
        MIT’s analysis prices storage at “about 6 cents per kilowatt-hour”, but grid balancing costs 3 €/MWh which would be deducted from that. Every little helps.
        
        And mechanical storage has a natural synergy with kinetic renewable energy, but MIT have failed to exploit that potential efficiency gain.
        http://cleantechnica.com/2013/04/30/mits-innovative-floating-wind-energy-storage-technology/
        
        Why is investment in the real (new energy tech) economy so painfully slow?
        
        An IMechE policy statement concurs with my (pro) storage position:-
        
        “The problem is that investors aren’t interested because they can achieve higher profits through other subsidised projects.”
        http://www.utilityweek.co.uk/news/news_story.asp?id=196966&title=Incentivise+electricity+storage+and+work+out+how+much+we+need%252C+engineers+tell+government
        
        btw: ‘The Engineer’ do editorial review on all comments before they publish. Regular posts assert that – “windfarms are useless”! Their freedom of speech is fine, but a guy just talking engineering concepts is somehow ‘offensive’? The Editor wasn’t at all upset by my ‘tongue-in-cheek’ comment on 5 Dec. 2012. He didn’t have to print it.
        http://www.theengineer.co.uk/opinion/comment/new-dash-for-gas-muddies-uks-energy-future/1014846.article#ixzz2EpvVlinV
        
        NB: The comment at 9.10pm below mine. More dumb science denial.
        
        And finally, Bob, you said:-
        
        ““I don’t care who figures out how to snatch us from the fossil fuel dragon. I just want us saved.” But you’re bitterly opposed, if Dave’s concepts (or VAWTs) turn out to be even a small part of the solution? You don’t make sense Bob, and “blowing smoke” concedes that you’ve run out of rational argument.
      - Bob_Wallace
        
        Dave – you make this assertion –
        
        ” We are going to need a very large capacity of the most viable energy storage we can devise, and that HAS to be before-generator, NOT after generation.”
        
        That is unproven and runs counter to the thinking of those who are actually working in the energy storage field.
        
        You hypothesize a mechanism which has never been built and which few people besides yourself find likely to be of value. You haven’t even produced the numbers needed to show how your sort of storage would fit into the natural flow of energy in the larger system.
        
        If you think you have a better idea it’s your job to prove it. As it is you are simply noise masking the signal.
      - Dave2020
        
        I’m sorry for wandering off-topic, but . . . .
        
        Bob, you evidently don’t understand how IP knowledge transfer works. I can only reveal design details under a confidentiality agreement, so nobody is yet in a position to fully understand the engineering specifics, let alone determine if they have any value!!
        
        YOUR supposition that my designs are “unproven and run counter to the thinking of those who are actually working in the energy storage field.” is just that – based on an ill-informed guess that the mechanisms have “never been built”. The fundamental principles of three elements are well proven and the proof of concept of another part already exists. It’s not just theory, but I can’t progress any further without expert help.
        
        When I met MGRover engineers in 2002, I took a model to Longbridge that was definitive proof of car suspension with no roll/handling compromise, but I wouldn’t reveal the mechanism inside. The engineers were fascinated, but said the management would never fund the R&D. Just as well MGR didn’t get their hands on the IPR – the Chinese bought all their assets.
        http://en.wikipedia.org/wiki/MG_Rover_Group
        
        By keeping those key design elements secret I still ‘own’ that IP. If I’d had patents granted back in 1990, anyone would be at liberty to use it.
Sean

how have they not done this sooner?
use the wind to displace coal heaters -> use the coal to burn when you need it/produce steel -> stop spending so much money importing coal

Chinese govt should hand out reverse cycle aircons and solar panels as part of their tax scheme
- Nathanael
  
  •
  
  6 hours ago
  
  −
  
  “how have they not done this sooner?”
  Lack of electric grid? Lack of electric heaters? Yeah, they should be handing out heat pumps as part of this scheme.
  - Bob_Wallace
    
    China has been installing wind at a very fast rate. A couple of years back they were curtailing some because they didn’t have transmission lines in place. I suspect they are just now reaching the point where supply during off-peak hours is significantly greater than demand. As the article says”The amount of curtailed wind power in 2012 was 20,000 GWh, approximately twice what it was in 2011.”
    
    The problem with handing out a lot of heat pumps is that they would need electricity when demand was taxing supply. The present solution gives China a place to use surplus wind power without increasing demand.