各国如何看待燃煤.docx

2013.01.05 The mixed fortunes of a fuel 各国如何看待燃煤Coal in the rich worldThe mixed fortunes of a fuelWhy is the worlds most harmful fossil fuel being burned less in America and more in Europe? The first of two stories looks at Americas cheap gas and new rulesIN A high-tech world, dirty black lumps of coal might seem like an anachronism. Yet coal is far from a thing of the past. However whizzy your iPad, your wall-mounted television or your electric car, the chances are that it is powered by the stuff. Coal-fired power stations provide two-fifths of the worlds electricity, and there are ever more of them. In the doubling of the worlds electricity production over the past decade, two-thirds of the increase came from coal. At these rates, coal will vie with oil as the worlds largest source of primary energy within five years. As recently as 2001, it was not much more than half as important as oil (see chart).The main factor has been the unslakable thirst for energy in China, which in 2011 overtook America as the worlds biggest electricity producer. In 2001, according to the International Energy Agency, a club of rich nations, Chinese coal demand was about 600m tonnes of oil equivalent (25 exajoules). By 2011 Chinas coal demand had tripleda rise from two-thirds of the energy America gets from oil to twice that amount. Chinas domestic coal industry produces more primary energy than Middle Eastern oil does.Other developing economies are just as keen on coal, if not yet on such a grand scale. In India, producing 650 terawatt hours of electricity in 2010 took 311m tonnes of oil equivalent, and the power sectors coal demand is growing at around 6% a year. The IEA reckons India could surpass America as the worlds second-largest coal consumer by 2017.But if America no longer dominates the business as it once did, what is happening to the industry there is still able to trigger changes far away. And at the moment coal is falling from favour in America.King no moreIn developing economies coals advantagesbeing cheap and widely availableare deemed to outweigh the damage it inflicts both on people near the places where it is burned (burning it gives off particles that harm peoples health) and on the planet as a whole (burning coal produces carbon dioxide, the most important long-lived greenhouse gas). In rich countries you might expect the cost-benefit balance to tip the other way, and coal use to be dropping. But things are not quite that simple. In America coal is indeed being burned less and lessbut not principally thanks to climate policy, of which America has relatively little. Meanwhile in Europe, which likes to see itself as a world leader on climate, they are using more and more of the stuff (see article).Americas coal business, like the rest of the countrys energy industry, has been upended by the advent of shale gas, now available in unforeseen quantities at unforeseen prices. In April 2012 the price fell below $2 per million British thermal units, or Btus ($7 per megawatt hour). This has made gas increasingly attractive to power companies, which have been switching away from coal in increasing numbers.At its peak, in 1988, coal provided 60% of Americas electricity. Even in 2010, when the shale-gas boom was well under way, it still accounted for 42%. By the middle of 2012, though, gas and coal were roughly neck-and-neck, each with around a third of power generation.There are two reasons for thinking the shift from coal may be long-lasting. One is that new gas is continuing to come on stream, and getting cheaper to produce. Though prices have started to rise from their earlier rock-bottom levels (they are now $3.43 per mBtu), it is unlikely to cost more than coal for a good while. And it will be fairly easy to use more gas without having to build new power stations. Around half of Americas gas-fired capacity is made up of so-called combined-cycle gas turbines (CCGT) which generate power come what may (the rest is used in “peakers” which generate only when needed). Utilisation rates in CCGTs have risen, but are still only 50%; they can use more.The other reason why coals decline as a fuel may continue is that gas plants meet environmental regulations more easily. In the second Obama administration these are likely to stay in place or be extended. The coal industrys lobbying power looks weaker following the election. Mitt Romney, who regularly attacked the presidents “war on coal”, had its full support, but that support did not deliver him the swing states of Virginia and Ohio.As things stand, power plants will have to comply with rules governing emissions of mercury and other toxic nasties by 2015. Court challenges to further rules to control emissions of sulphur dioxide and oxides of nitrogen may delay these new standards, but will not kill them. And environmental rules promulgated under the Clean Air Act do not require congressional approval. Should Mr Obama decide to make environmental policy by fiat, the coal industry will feel the pinch.The Environmental Protection Agency has already proposed restrictions on carbon emissions which would in practice ban new coal-fired plants after 2013 unless fitted with carbon capture and storage (CCS)a technology has not yet been made to work on a commercial basis, though facilities planned for California and Texas may change that. Even without CCS, modern coal-fired power plants, though more efficient than the old ones and capable of being made a lot cleaner, are more expensive than those using old technology. They are twice the price of gas-fired plants with the same capacity. A gas facility can also be built in two to four years, instead of four to eight, giving utilities more flexibility when adding capacity.This bodes ill for Americas coal plants. The combination of cheap gas and expensive regulation means that 50 gigawatts of coal-fired power capacitya sixth of the totalcould be shut down by 2017, according to Navigant, a consultancy. Others put the figure higher.This means trouble for Americas coal miners. Coal production is likely to have fallen by roughly 100m tonnes in 2012, compared with 2011, or around 10% of the total. A surge in exports softened the blow: they rose by a quarter in the first half of 2012, to around 66m tonnes. The industrys infrastructure is not geared to exportit is hard to get coal from Wyoming on to ships bound for Chinabut if that were rectified, analysts reckon, exports could reach 200m tonnes a year. In the meantime mining companies have been closing pits, shedding jobs and consolidating, especially in the least efficient mining areas of central Appalachia (West Virginia and Kentucky).The decline of coal, though, will be protracted. Coal-fired power stations are built to lastthe oldest plant currently operating was built in the 1930sso unless new rules force them to close, they will be retired gradually. By 2017 or so, reckons Brattle Group, a consultancy, coal use will stabilise again, as gas demand finally makes gas prices dearer than coal. Coal may be down in America. But it is not yet out.各国如何看待燃煤发达国家中的燃煤应用为何燃煤，这一危害性最大的矿物燃料在美国使用较少，而在则欧洲消耗较多？我们将对美国廉价燃气和新环保法规进行报道，此为上半部分。在一个科技高速发展的世界里，肮脏的黑色煤块似乎显得格格不入，然而它仍在这个时代中发挥着作用。无论iPad，壁挂电视或电动汽车技术如何高新，它们使用的电能很可能就来自于燃煤，而全球五分之二的电力供应便来自燃煤发电站，而且燃煤发电量大有增长的趋势。全球发电量在过去的十年间增长了一倍，这一大幅增长中有三分之二来自燃煤发电。以这一趋势计算，未来不到五年，燃煤将与石油争夺世界最大基础性能源的位置。但就在2001年，燃煤的重要性还不及石油一半（详见图表）。燃煤使用量攀升的主要原因在于中国对于能源的大量需求，其在2011年已超过美国，跃升为世界最大电力产出国。根据发达国家所组成的国际能源理事会协相关报告，2001年中国燃煤需求约为6亿吨油当量（约合25千兆焦耳），是美国石油消耗产出能源的三分之二；到2011年中国燃煤需求量增加了三倍，为美国石油消耗产出能源的整整两倍。以一次能源而言，中国国内燃煤使用所得要比中东地区石油产出消耗所得还要多。其它发展中国家对燃煤的需求虽未达到中国的规模，但燃煤仍是它们发展的重要支柱。印度在2010年燃煤发电量达到650太瓦小时，相当于3.11亿油当量吨，其每年发电部门燃煤需求以每年6%的速度递增。据此，国际能源理事会估算到2017年，印度将超越美国，成为世界第二大燃煤消耗国。但如果美国不再主宰燃煤产业的话，美国能源产业的动向依然在世界范围内会产生巨大影响。当前，燃煤在美国的重要性正在逐步下降风光不再 燃煤的优势在于价格低廉，且易广泛开采。而危害则在于燃烧过程中所产生的废气对附近人群健康产生危害，而且析出气体对整个地球大气带来威胁（燃煤所析出的颗粒物对人体健康有害，而所产生的二氧化碳是最重要的长期存在的温室气体）。而对于发展中国家则更看重燃煤的优势。在发达国家，你也许会期待政府基于利害平衡考虑而减少燃煤的使用。但事实并非这么简单。在美国，燃煤使用确实在减少，但并非出于环保条例的保护作用。相反，美国环保条例对燃煤限制相对较小；于此同时，在那些喜欢将自己标榜为气候政策倡导者的欧洲各国，他们的燃煤使用却在不断增加。页岩燃气横空出世，不仅使当前美国燃气价格持续波动，也很难估测储量，还彻底扭转美国燃煤产业，和该国其它能源产业的命运。在2012年4月，页岩燃气价格降到每百万英国热量单位2美元以下（每兆瓦小时7美元）。这使得电力厂商越来越青睐于燃气，也开始逐步将燃煤发电站改造为燃气发电站。1988年，美国燃煤发电处于顶峰时期，提供该国60%的电力供应。即使是在2010年，页岩燃气迅速发展之际，燃煤电力仍占全国电力总供应量的42%。即使在2012年中期，燃气发电量与燃煤发电量仍大抵持平，均为全国电力总供应量的三分之一。出于两方面原因的考虑，美国不再依赖燃煤（shift from coal）这一趋势会长久持续。一是人们不断探测到新燃气资源，使得开采成本进一步下降。尽管燃气价格开始从先前的峰谷阶段开始爬升（现在每百万英国热量单位为3.43美元）。但在很长的一段时间内，其价格不可能超过燃煤价格。并且，在不兴建新发电站的前提下提高燃气使用量是完全可以做到的。美国大约一半的燃气发电站采用所谓的复合循环燃气轮机发电，能在任何情况下都同样发电（其它则作为“用电尖峰锅炉”，只在需要时发电）。复合循环燃气轮机发电的有效利用率已有提高，但仍仅为50%，还有增长的空间。另一导致燃煤使用量继续下滑的原因是燃气发电能更容易地到达环保条款的要求。在奥巴马的第二个行政期内，所设的环保条例有可能不作变化或延长使用。燃煤产业的游说力