ronwagn + 6,290 October 1, 2019 https://oilprice.com/Energy/Energy-General/Chinas-Renewable-Boom-Hits-The-Wall.html 1 Quote Share this post Link to post Share on other sites
markslawson + 1,057 ML October 2, 2019 10 hours ago, ronwagn said: https://oilprice.com/Energy/Energy-General/Chinas-Renewable-Boom-Hits-The-Wall.html   I would draw everyone's attention to this part of the linked story.. there is another reason: curtailment. China-based journalist Michael Standaert wrote in a recent story for Yale Environment 360 that China’s solar and wind farms continue to produce electricity that is wasted because there is not enough transmission capacity. Renewable energy is a top priority for China as it fights one of the worst air pollution levels in the world while subject to an uncomfortably high degree of reliance on energy imports, namely oil and gas. This lack of transmission capacity has been a problem for decades now that I can remember.. The Chinese system is set up to build renewables but not to link them to anything. The regional party bosses just have to point to wind and solar generating assets to show that they are meeting their targets. Just what those generators might be linked to, or not, is not relevant. Also note that they are worried about urban pollution. It is known that much of that pollution is due to coal fires lit by poorer Chinese families who have flocked to the large cities and are trying to keep warm. Cutting the output of power plants, often well outside the cities even in China, won't do much, but switching the poor families over to gas will. There are indications that Chinese are trying to do that, but it is typical of the confusion in the area that renewables are cited as a solution to the wrong problem.  1 1 1 Quote Share this post Link to post Share on other sites
ronwagn + 6,290 October 2, 2019 21 hours ago, markslawson said:  I would draw everyone's attention to this part of the linked story.. there is another reason: curtailment. China-based journalist Michael Standaert wrote in a recent story for Yale Environment 360 that China’s solar and wind farms continue to produce electricity that is wasted because there is not enough transmission capacity. Renewable energy is a top priority for China as it fights one of the worst air pollution levels in the world while subject to an uncomfortably high degree of reliance on energy imports, namely oil and gas. This lack of transmission capacity has been a problem for decades now that I can remember.. The Chinese system is set up to build renewables but not to link them to anything. The regional party bosses just have to point to wind and solar generating assets to show that they are meeting their targets. Just what those generators might be linked to, or not, is not relevant. Also note that they are worried about urban pollution. It is known that much of that pollution is due to coal fires lit by poorer Chinese families who have flocked to the large cities and are trying to keep warm. Cutting the output of power plants, often well outside the cities even in China, won't do much, but switching the poor families over to gas will. There are indications that Chinese are trying to do that, but it is typical of the confusion in the area that renewables are cited as a solution to the wrong problem.  I have fallen prey to the thinking that a top down government often works more efficiently, as in the trains run on time. That may be true but it depends on the overall culture, leadership at all levels, means etc. Actually a free economy is more effective unless it is mismanaged. That mismanagement is often caused by politicians who buy votes through overspending with funny money. That leads to economic collapse. 2 Quote Share this post Link to post Share on other sites
John Foote + 1,135 JF November 11, 2019 On 10/1/2019 at 7:22 PM, markslawson said: This lack of transmission capacity has been a problem for decades now that I can remember.. That was a major issue in Texas as the grid was being expanded. For a time the windmills were going up faster than the ulta high voltage DC lines to carry the juice to where is could be used. T.B. Pickens tried to get a law put in allowing him to put in pipelines under new power lines. He wanted the pipelines to transport water, not gas or oil. He bought up silly amounts of land to take advantage of the right of capture laws in Texas for underground water, with the intent of selling the water to municipalities that needed it. 1 1 Quote Share this post Link to post Share on other sites
Marcin + 519 MS November 11, 2019 On 10/2/2019 at 2:22 AM, markslawson said: This lack of transmission capacity has been a problem for decades now that I can remember.. The Chinese system is set up to build renewables but not to link them to anything. The regional party bosses just have to point to wind and solar generating assets to show that they are meeting their targets. Just what those generators might be linked to, or not, is not relevant. Also note that they are worried about urban pollution. It is known that much of that pollution is due to coal fires lit by poorer Chinese families who have flocked to the large cities and are trying to keep warm. Cutting the output of power plants, often well outside the cities even in China, won't do much, but switching the poor families over to gas will. There are indications that Chinese are trying to do that, but it is typical of the confusion in the area that renewables are cited as a solution to the wrong problem. Â Very good point. That is why Chinese further accelerated around 2008 (stimulus) already fast pace of transmission grid construction. They are using UHV AC (1000kV) and DC lines (800 and 1100kv), nobody in the world (bar 1 in India) uses such technology, already finished 22 of them. The largest could transmit up to 12 GWs of power, yes it is not spelling error 12,000 MW of power. This already substantially decreased curtailment. What China is also doing it is trying to mitigate renewables hype, bring more economic sustainability to renewables. Construction around the world is also past its peak (in wind) and reaching peak (in solar) so it is good to lower expectations, as future of vast Chinese renewables industry is at stake. 1 1 Quote Share this post Link to post Share on other sites
markslawson + 1,057 ML November 11, 2019 3 hours ago, Marcin said: They are using UHV AC (1000kV) and DC lines (800 and 1100kv), nobody in the world (bar 1 in India) uses such technology, already finished 22 of them. The largest could transmit up to 12 GWs of power, yes it is not spelling error 12,000 MW of power. This already substantially decreased curtailment. Actually 12 GWs is not all that much in the context of the Chinese economy and, as they are building conventional power plants like crazy, they certainly would want that extra capacity.. whether any of it is used to connect wind turbines and the like is another issue.. The vast bulk of Chinese renewable energy is Hydro, not wind or solar.. although you do say "substantially reduced curtailment".. are you referring to anything in particular.. finding current information on the Chinese grid can be hard. Do you have a link? Its interesting that they are using so many DC lines.. any idea why? 2 Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,190 November 12, 2019 (edited) UHVDC is slightly superior to AC for long distance power lines(2 lines instead of 3) and power loss. It was never really possible before the advent of large power transistors. So anything built before ~1980 could not do it. USA grid was mostly built before 1980. Why Canada with its new Hydro being built is using UHVDC. For instance the run between Manitoba and Minneapolis. Or the underwater cable between Norway and Scotland. Likewise, UHVDC can be run UNDER ground and more importantly under water much more cheaply than UHVAC as it does not have the capacitance problem of multiconductor or single conductor shielded cable. In fact UHVAC can't be run underground at all(at least I do not know of any). So, only medium AC voltages are used. Disadvantages? Sucks for short/medium distances as changing from DC to AC is complex and expensive.... VERY expensive and you lose a bit of power compared to AC. So, distance loses of AC verses conversion losses of DC.... Neither are EMP proof. PS: the 12GW line is a ~whatever. HVDC run at 0.5 and 1 million volts so you are talking a mere couple of amps. Difference is these HVDC lines can be run underwater so the connection between France and the UK comes to mind. Nothing is free in this world. *** EDIT: UHVDC is important for wind energy as this allows us to use HVDC generators on the wind turbines themselves(they do not care about RPM variations... ***much***) and have no conversion losses. In my youth I was working on such systems in the Columbia River Gorge and different turbine designs. Edited November 12, 2019 by footeab@yahoo.com 1 3 Quote Share this post Link to post Share on other sites
NickW + 2,714 NW November 12, 2019 13 hours ago, Marcin said: Very good point. That is why Chinese further accelerated around 2008 (stimulus) already fast pace of transmission grid construction. They are using UHV AC (1000kV) and DC lines (800 and 1100kv), nobody in the world (bar 1 in India) uses such technology, already finished 22 of them. The largest could transmit up to 12 GWs of power, yes it is not spelling error 12,000 MW of power. This already substantially decreased curtailment. What China is also doing it is trying to mitigate renewables hype, bring more economic sustainability to renewables. Construction around the world is also past its peak (in wind) and reaching peak (in solar) so it is good to lower expectations, as future of vast Chinese renewables industry is at stake. Stop introducing facts and solutions into a good old Oil Price debate on renewables. 2 3 Quote Share this post Link to post Share on other sites
NickW + 2,714 NW November 12, 2019 9 hours ago, markslawson said: Actually 12 GWs is not all that much in the context of the Chinese economy and, as they are building conventional power plants like crazy, they certainly would want that extra capacity.. whether any of it is used to connect wind turbines and the like is another issue.. The vast bulk of Chinese renewable energy is Hydro, not wind or solar.. although you do say "substantially reduced curtailment".. are you referring to anything in particular.. finding current information on the Chinese grid can be hard. Do you have a link? Its interesting that they are using so many DC lines.. any idea why? 2018 figures 366 TWH from wind 178 TWH from Solar 1233 TWH from Hydro. China has only just started offshore wind development so that could easily double that 366 TWH figure. 1 1 Quote Share this post Link to post Share on other sites
NickW + 2,714 NW November 12, 2019 9 hours ago, markslawson said: Actually 12 GWs is not all that much in the context of the Chinese economy and, as they are building conventional power plants like crazy, they certainly would want that extra capacity.. whether any of it is used to connect wind turbines and the like is another issue.. The vast bulk of Chinese renewable energy is Hydro, not wind or solar.. although you do say "substantially reduced curtailment".. are you referring to anything in particular.. finding current information on the Chinese grid can be hard. Do you have a link? Its interesting that they are using so many DC lines.. any idea why? Efficiency - losses per 100km of line are about 1/3rd of the equivalent AC system. Its why virtually all long distance transmission lines are now built in DC. 3 Quote Share this post Link to post Share on other sites
Marcin + 519 MS November 12, 2019 9 hours ago, markslawson said: Actually 12 GWs is not all that much in the context of the Chinese economy and, as they are building conventional power plants like crazy, they certainly would want that extra capacity.. whether any of it is used to connect wind turbines and the like is another issue.. The vast bulk of Chinese renewable energy is Hydro, not wind or solar.. although you do say "substantially reduced curtailment".. are you referring to anything in particular.. finding current information on the Chinese grid can be hard. Do you have a link? Its interesting that they are using so many DC lines.. any idea why? I read articles about substantially decreased curtailment (like from 25-30% to under 5-10%). These were pretty specific numbers about wind curtailment listed by provinces. There are maps of UHV lines, they are clustering from Western/South Western (rich in hydro, wind and solar power) provinces into hungry East. Quote Share this post Link to post Share on other sites
Marcin + 519 MS November 12, 2019 19 minutes ago, NickW said: Efficiency - losses per 100km of line are about 1/3rd of the equivalent AC system. Its why virtually all long distance transmission lines are now built in DC. Exactly, there are graphs that show distance vs losses comparison in AC and DC transmission at certain voltages. New transformers are very efficient, grid is more stable with DC as less problems with synchronization. In Chinese situation land usage is also important, less footprint of DC. Quote Share this post Link to post Share on other sites
Marcin + 519 MS November 12, 2019 25 minutes ago, NickW said: 2018 figures 366 TWH from wind 178 TWH from Solar 1233 TWH from Hydro. China has only just started offshore wind development so that could easily double that 366 TWH figure. I think Hydro will dominate on TWh basis, while wind, solar can exceed hydro in nameplate capacity. Theoretical Chinese hydro potential is 6000 TWh. China is building rail infrastructure in remote regions, like in Tibet to allow to tap more of this potential. The largest hydro plant in the world is yet to be built in Yarlung Tsangbo Canyon at about 35000-40000 MW. But Tibet-Sichuan railway is needed first. China will get to about 2500 TWh of hydro. Quote Share this post Link to post Share on other sites
NickW + 2,714 NW November 12, 2019 51 minutes ago, Marcin said: I think Hydro will dominate on TWh basis, while wind, solar can exceed hydro in nameplate capacity. Theoretical Chinese hydro potential is 6000 TWh. China is building rail infrastructure in remote regions, like in Tibet to allow to tap more of this potential. The largest hydro plant in the world is yet to be built in Yarlung Tsangbo Canyon at about 35000-40000 MW. But Tibet-Sichuan railway is needed first. China will get to about 2500 TWh of hydro. Hydro works very well hand in hand with solar and wind as even run of river plants have some flexibility to ramp up and down to help manage variability in wind and solar. 1 Quote Share this post Link to post Share on other sites
ronwagn + 6,290 November 12, 2019 7 hours ago, NickW said: Efficiency - losses per 100km of line are about 1/3rd of the equivalent AC system. Its why virtually all long distance transmission lines are now built in DC. This reminds me of the old struggle between Tesla on his AC invention and Edison who was stuck on DC. The worm has turned although you are writing over my head. Same with those who try to explain the complexities of engines. 1 Quote Share this post Link to post Share on other sites
remake it + 288 November 12, 2019 6 hours ago, ronwagn said: This reminds me of the old struggle between Tesla on his AC invention and Edison who was stuck on DC. The worm has turned although you are writing over my head. Same with those who try to explain the complexities of engines. I hope this explains both issues simply enough. 1 1 Quote Share this post Link to post Share on other sites
ronwagn + 6,290 November 12, 2019 I really appreciate the article. I will try to get back to it when I am not groggy. It looks very good. 1 1 Quote Share this post Link to post Share on other sites
markslawson + 1,057 ML November 12, 2019 (edited) 14 hours ago, NickW said: 2018 figures 366 TWH from wind 178 TWH from Solar 1233 TWH from Hydro. China has only just started offshore wind development so that could easily double that 366 TWH figure. Okay - I have no reason to doubt those figures. As you can see hydro dominates by quite a margin on installed capacity but, of course, hydro is high value dispatchable power while solar and wind are low value intermittent. The Chinese grids also don't have anything like the sophistication of their Western equivalents and are still told what to produce at what prices - but of course, as you say, hydro and wind can be made to work well together.. Edited November 12, 2019 by markslawson correcting a typo 2 Quote Share this post Link to post Share on other sites
remake it + 288 November 12, 2019 5 minutes ago, markslawson said: The Chinese grids also don't have anything like the sophistication of their Western equivalents.... Oh? 1 Quote Share this post Link to post Share on other sites
markslawson + 1,057 ML November 12, 2019 5 minutes ago, remake it said: Oh? Good article, but I don't think you realise what you've linked. This is about the transmission system, not the local grids which still have considerable legacies from the old days of central authorities. They don't have a trading mechanism, or mostly don't, which the Western grids have to help them determine which type of energy is used. There are other problems. Now the article points to efforts to build, at immense cost, a network to overcome the problem of renewable energy being produced in the wrong regions - all good, and I thank you for drawing my attention to it. But note they are still building it and its an unusual design. Oh oh! If they get it running properly that's good but it underlines the immense cost and difficulties involved in tapping into "cheap" green electricity. Anyway, thanks for that. Leave it with you. 1 2 Quote Share this post Link to post Share on other sites
remake it + 288 November 13, 2019 26 minutes ago, markslawson said: Good article, but I don't think you realise what you've linked. This is about the transmission system, not the local grids which still have considerable legacies from the old days of central authorities. They don't have a trading mechanism, or mostly don't, which the Western grids have to help them determine which type of energy is used. Trading mechanisms unnecessarily complicate grids and are not actually "efficient" because they rely on bid prices rather than energy source, so whereas the West may not prioritize renewables, China always can. 32 minutes ago, markslawson said: But note they are still building it and its an unusual design. Oh oh! If they get it running properly that's good but it underlines the immense cost and difficulties involved in tapping into "cheap" green electricity. The grid for renewable integration is largely a retrofit for Western economies - expensive and complex -  but is largely being purpose built for massive new renewables capacity projects in China, so there are significant cost tradeoffs that are advantageous to China. 1 Quote Share this post Link to post Share on other sites
markslawson + 1,057 ML November 13, 2019 22 hours ago, remake it said: Trading mechanisms unnecessarily complicate grids and are not actually "efficient" because they rely on bid prices rather than energy source, so whereas the West may not prioritize renewables, China always can. Remake - you seriously need to do some reading.. the price pools run by western grids actually favours renewable energy. The response by some grids to renewables messing up the price pools is to start a capacity market. As for your assertion that these market mechanisms are an unnecessary complication I am at a loss for words. In fact the Western grids now can't do without them.. You also assert that there are significant cost trade offs in this transmission grids. That is not evident at all. You're talking about building DC lines over very substantial distances - potentially costing hundreds of billions - in order to overcome the problem of renewable generation being in one area and the power consumption in another. Conventional power plants built close to the consumers would be far cheaper, even after the cost of fuel is taken into account. Now that's enough.. time to move onto other topics. 1 1 1 Quote Share this post Link to post Share on other sites
remake it + 288 November 14, 2019 30 minutes ago, markslawson said: Remake - you seriously need to do some reading.. the price pools run by western grids actually favours renewable energy. The response by some grids to renewables messing up the price pools is to start a capacity market. You should check your facts better about how electricity markets operate as your claim is partially true, else for example here. 37 minutes ago, markslawson said: As for your assertion that these market mechanisms are an unnecessary complication I am at a loss for words. In fact the Western grids now can't do without them.. For all practical purposes the grid is just the system to produce electricity and supply it as energy, while market mechanisms are what operators use to select who gets what from where, and that is where China is advantaged in terms of how it chooses to preference renewables over other energy sources (command economy versus market economy). 2 hours ago, markslawson said: You also assert that there are significant cost trade offs in this transmission grids. That is not evident at all. Retrofitting an existing grid to accommodate/integrate renewable energy is more expensive than a grid purpose built for the energy sources to be accessed. 1 hour ago, markslawson said: You're talking about building DC lines over very substantial distances - potentially costing hundreds of billions - in order to overcome the problem of renewable generation being in one area and the power consumption in another. Conventional power plants built close to the consumers would be far cheaper, even after the cost of fuel is taken into account. Estimated cost for 50 million Chinese households is about $35 billion, but you forgot that coal is also not always close to population centres so your idea about conventional power plants not only has the issue of transmission but also of cost of energy source. 3 Quote Share this post Link to post Share on other sites
Marcin + 519 MS November 14, 2019 @remake it @markslawson so guys a few things have to be sorted out, you are both right (80%) and a little bit wrong (20%) at the same time: 1. Chinese transmission grid is much better than United States: definitely more modern, much higher voltages, lower losses etc. Of course it also has much higher capacity but this is obvious as generation capacity much higher by wide margin, to give 2 numbers: 2018 generation US: 4.3 trn kWh, China 7.1 trn kWh (still fast rising). I do not know what is the gap but I think it is about 10 years, in 5 years it will be 14 years etc., the pattern is clear as US has stalled its grid investment long time ago. Believe or what I encourage check yourself. 2. Nearly every (I do not have knowledge about all countries, but definitely true for US and China. More for US than China, China is more reasonable) is favouring renewable generation. Tariffs for transmission are very complex, do not remember or understand them any longer, not worked for industry for 10+ years. They pay for capacity of baseload generation (gas, coal, nuclear, hydro) because when wind not blowing and sun not shining we would be all basicly f*cked with blackout. 3. UHV DC transmission is definitely good choice for China, it is a good investment in term of economic benefits. Vast country, very large loads, a lot of renewables, vast distances from generation to consumption centers (1000-3000 km ). UHV DC line 1100 kV 12 GW losses rough estimation is 2% per 1000 km transmission distance. Highest voltage line in US is 500kV DC 3 GW line loss is 10% per 1000 km transmission distance. Relative increase in Voltage decreases losses by about square of this increase, 1000 kV 4 times lower losses than 500 kV line. Lets do some maths: Costs of lines: 1100 kV 12 GW 3400 km line 40 billion CNY (6 billion USD). Take cost of wind power at 2 mln USD per 1 MW (I do not know what is exact price in China). So building 12 GW wind farm in Xinjang is 24 billion USD. Cost of transmission line for this power 3400 km to Shanghai is 6 billion USD. 25% of cost of power plant so very reasonable. Of course this is very simplified picture as loads are managed and higher wind power will switch off coal plants and lower wind output would increase power transmitted from coal plants, so generally costs are much lower than this 25% in comparison to costs of generation  You can further play with numbers, calculate how much you save on higher voltage in losses, make the calculation for transmission line as a project to calculate its rate of return. Calculate the safety of whole grid etc. Chinese made all these calculations so apart from their goal to make all the world gape in awe it was sound business wise. 1 1 2 Quote Share this post Link to post Share on other sites
ronwagn + 6,290 November 14, 2019 18 hours ago, markslawson said: Remake - you seriously need to do some reading.. the price pools run by western grids actually favours renewable energy. The response by some grids to renewables messing up the price pools is to start a capacity market. As for your assertion that these market mechanisms are an unnecessary complication I am at a loss for words. In fact the Western grids now can't do without them.. You also assert that there are significant cost trade offs in this transmission grids. That is not evident at all. You're talking about building DC lines over very substantial distances - potentially costing hundreds of billions - in order to overcome the problem of renewable generation being in one area and the power consumption in another. Conventional power plants built close to the consumers would be far cheaper, even after the cost of fuel is taken into account. Now that's enough.. time to move onto other topics. You brought up one of my favorite topics which is the possibility of localizing energy plants thus making those areas more secure. That can be done by focusing on natural gas pipelines and facilities for cities of all sizes that are not remote. Trucking can carry CNG or LNG as well as propane. So can trains. Some of this is being done to corporations in New England. That is due to the blockage of pipelines through New York, which could be bypassed by using LNG or CNG carried by ships to ports in New England. 2 Quote Share this post Link to post Share on other sites