Solar power production undercut by coal pollution
Solar power production undercut by coal pollution
太阳能发电受煤炭污染掣肘
Coal is by far the most polluting fuel that we use. It produces the most carbon emissions per unit of energy, and impurities in the coal produce a lot of sulfur dioxide aerosols, as well as nitrous and nitrogen oxides. Then there’s the coal ash that’s left behind, which typically contains a lot of toxic metals. The health benefits of displacing coal power are typically estimated to be well above the costs of the new generating equipment. But a new study suggests that the problems with coal-derived pollution go beyond health; it interferes with other power sources. Researchers have found that aerosols, both natural and human-derived, significantly reduce the power we could be getting from solar panels, to the tune of hundreds of terawatts a year. And a lot of those aerosols come from burning coal.
煤炭是我们目前使用中最具污染性的燃料。它在单位能源产出中产生的碳排放量最高，且煤炭中的杂质会产生大量的二氧化硫气溶胶，以及氮氧化物。此外，燃烧后留下的煤灰通常含有大量有毒金属。通常认为，淘汰煤电所带来的健康益处远高于更换新发电设备的成本。但一项新研究表明，煤炭污染带来的问题不仅限于健康领域，它还会干扰其他能源的生产。研究人员发现，无论是天然还是人为产生的气溶胶，都会显著降低太阳能电池板的发电效率，每年损失的电量高达数千太瓦时（TWh）。而其中很大一部分气溶胶正是源于燃煤。
A big impact
巨大的影响
The new work, done by a team in the UK, is based on a new global inventory of solar facilities. This started with known inventories of solar facilities, and was supplemented with AI-analyzed satellite imagery and crowdsourced records of locations. Satellite images were then used to determine the size of these facilities, and location-tagged weather data could then be used to estimate their power production. That could then be used to estimate what the facilities would be producing if clouds and/or aerosols weren’t scattering the sunlight that would otherwise reach the panels. This produced some significant numbers. In 2023, for example, over a quarter of the potential solar power production was lost, with over 20 percent due to clouds and another 6 percent from aerosols. That works out to be a bit over 500 terawatt-hours, or the full annual output of 84 coal plants (each with a 1 GW generating capacity).
这项由英国团队完成的新研究，基于一份全新的全球太阳能设施清单。研究人员首先利用已知的太阳能设施清单，并辅以人工智能分析的卫星图像及众包地理位置记录。随后，通过卫星图像确定这些设施的规模，并结合带有地理标签的气象数据来估算其发电量。在此基础上，研究人员推算出如果云层和气溶胶没有散射本应照射到电池板上的阳光，这些设施本应产生的电量。结果显示出惊人的数字：例如在2023年，超过四分之一的潜在太阳能发电量被损耗，其中超过20%归因于云层，另有6%归因于气溶胶。这相当于损失了超过500太瓦时的电量，即84座煤电厂（每座装机容量为1吉瓦）的全年总发电量。
Aerosols alone are a major contributor to these losses. The researchers note that, for the five years leading up to 2023, we installed enough solar capacity to produce an average of 250 TW-hr of additional power per year, but were losing 75 TW-hr of that to aerosols. (Obviously, solar production kept going up because the existing capacity rose each year.)
仅气溶胶一项就是造成这些损失的主要因素。研究人员指出，在2023年之前的五年里，我们安装的太阳能装机容量平均每年可额外产生250太瓦时的电力，但其中有75太瓦时因气溶胶而损失。（当然，由于现有装机容量逐年增加，太阳能总产量仍在持续上升。）
Regional differences
区域差异
The researchers note that aerosols can also contribute to cloud formation, which also causes further losses. But the degree of that contribution is much harder to estimate, so the researchers focus on aerosols for much of the analysis. Some of those aerosols occur naturally, typically from dust kicked up by winds in desert regions. However, despite deserts’ reputation as sunny paradises, the world as a whole hasn’t built much solar infrastructure in the desert yet, so this isn’t as much of a factor as you might expect. Coal appears to be a major contributor. It’s estimated that sulfur dioxide aerosols, primarily produced through coal burning, account for nearly half of the aerosols analyzed here. Carbon-rich material, which also typically comes from fossil fuels, accounts for another 18 percent.
研究人员指出，气溶胶还会促进云层形成，从而导致进一步的电量损失。但由于这一贡献程度极难估算，研究人员在大部分分析中将重点放在了气溶胶本身。部分气溶胶是自然产生的，通常来自沙漠地区风吹起的沙尘。然而，尽管沙漠被视为阳光充足的“天堂”，但全球范围内在沙漠中建设的太阳能基础设施并不多，因此这并非预想中那么大的影响因素。煤炭似乎是主要贡献者。据估计，主要由燃煤产生的二氧化硫气溶胶占了此次分析中气溶胶总量的近一半。同样通常来自化石燃料的富碳物质则占了另外18%。
The impact of aerosols, however, is not evenly distributed. In China, the researchers estimated that aerosols were reducing solar production by 7.7 percent overall and offsetting anywhere from a third to half of its annual growth. The researchers note that “the spatial distribution of photovoltaic losses in China mirrors that of its coal-fired power capacity,” and an analysis of pollution data from China shows that 30 percent of the losses due to aerosols can be attributed to coal burning. In contrast, most solar production in the US takes place in the south and west, while coal plants are more common in the east and northeast. As a result, the annual losses in the US were less than half of those seen in China (3 percent).
然而，气溶胶的影响分布并不均匀。研究人员估计，在中国，气溶胶使太阳能总发电量减少了7.7%，并抵消了其年度增长的三分之一到一半。研究人员指出，“中国光伏发电损失的空间分布与其燃煤电厂的分布相吻合”，对中国污染数据的分析显示，30%的气溶胶相关损失可归因于燃煤。相比之下，美国的太阳能发电主要集中在南部和西部，而煤电厂则更多分布在东部和东北部。因此，美国每年的损失率不到中国的一半（3%）。
The good news is that things are getting better in China. In response to some severe pollution problems, the country built a new generation of high-efficiency coal plants and retired some of the worst polluters. And the data show that this is also benefiting solar power, with the impact of aerosols dropping over the last few years. Even with the improvements, it’s striking that coal appears to be the only power source that actively reduces the productivity of what’s shaping up to be its primary competitor. It should also provide an impetus to move off coal more quickly, as at least some of the loss of coal production will be offset by enhanced productivity from solar.
好消息是，中国的情况正在好转。为了应对严重的污染问题，中国建设了新一代高效煤电厂，并淘汰了一些污染最严重的设施。数据显示，这也使太阳能发电受益，气溶胶的影响在过去几年中有所下降。尽管有所改善，但令人震惊的是，煤炭似乎是唯一一种会主动降低其主要竞争对手（太阳能）生产力的能源。这也应成为加速摆脱煤炭依赖的动力，因为至少部分煤电产量的损失将通过太阳能生产力的提升得到补偿。