评论
打印
Science and technology
科技版块
Renewable energy
可再生能源
A census of solar-cells
太阳能电池调查
An accurate count of the Earth's solar-power stations has now been made
现在已经对地球上的太阳能发电站进行了准确的统计
REBUILDING AN ENTIRE planet's energy system is a big job.
重建整个星球的能源系统是一项艰巨的工作。
Just ask the delegates at the COP-26 climate conference scheduled to kick off in Britain on October 31st.
只要问问10月31日在英国开幕的COP-26气候大会的代表们就知道了。
The most basic problem is knowing what, exactly, you are trying to rebuild.
最基本的问题是确切地知道你重建的是什么。
Academic-research groups, think-tanks, charities and other concerned organisations try to keep track of the world’s wind turbines, solar-power plants, fossil-fuelled power stations, cement factories and so on.
学术研究团体、智囊团、慈善机构和其他相关组织试图跟踪世界上的风力涡轮机、太阳能发电厂、化石燃料发电厂、水泥厂等。
To this end, they rely heavily on data from national governments and big companies, but these are often incomplete.
为此，他们严重依赖各国政府和大公司的数据，但这些数据往往是不完整的。
The most comprehensive database covering American solar-power installations, for instance, is thought to miss around a fifth of the photovoltaic panels actually installed on the ground.
例如，覆盖美国太阳能装置最全面的数据库被认为遗漏了大约五分之一的实际安装在地面上的光伏电池板。
In a paper just published in Nature, a team of researchers led by Lucas Kruitwagen, a climate scientist and AI researcher at Oxford University, demonstrate another way to keep tabs on the green-energy revolution.
在刚刚发表在《自然》杂志上的一篇论文中，由牛津大学气候学家兼人工智能研究员卢卡斯·克鲁特瓦根领导的研究团队展示了另一种密切关注绿色能源革命的方法。
Dr Kruitwagen and his colleagues have put together an inventory of almost 69,000 big solar-power stations (defined as those with a rated capacity of 10kW of electricity or more) all over the world—more than four times as many as were previously listed in public databases.
克鲁特瓦根博士和他的同事们整理了一份全球近69000个大型太阳能发电站的清单（额定发电量为10kW或以上的发电站）——是之前公共数据库中列出数量的四倍多。
This new inventory includes their locations, the date they entered service and a rough estimate of their generating capacity.
这份新的库存包括它们的位置，它们投入服务的日期，以及对它们发电量的粗略估计。
Conceptually, the team's method is simple.
从概念上讲，这个团队的方法很简单。
Instead of relying on top-down reports, they worked from the bottom up, looking at the entire planet from space and counting how many solar panels they could see.
他们不依赖于自上而下的报告，而是自下而上地工作，从太空观察整个星球，并计算他们能看到多少太阳能电池板。
This is not the first time people have hunted from orbit for solar-power stations.
这已经不是人们第一次在轨道上寻找太阳能发电站了。
But previous analyses have been limited to a few countries.
但之前的分析仅限于少数几个国家。
As far as Dr Kruitwagen knows, his is the first attempt to survey the entire planet for a particular type of infrastructure.
就克鲁特瓦根博士所知，他是第一次尝试在整个星球上勘测某种特定类型的基础设施。
Earth is a big place, of course, which means practice is a great deal harder than theory.
当然，地球是一个很大的地方，这意味着实践要比理论困难得多。
His approach has been made possible by two big technological trends.
两大技术趋势使他的方法成为可能。
One is a growing abundance of cheap, easily available satellite imagery.
其一是越来越多的廉价且容易获取的卫星图像。
In the 20th century, reconnaissance satellites were the jealously guarded property of a handful of governments.
在20世纪，侦察卫星是少数几个政府小心翼翼守卫的财产。
These days, a cottage industry of Earth-observation firms and agencies sells images on the open market.
如今，由地球观测公司和机构组成的家庭式手工业已经开始在公开市场上出售图像。
Dr Kruitwagen's pictures came from two sets of satellites, Sentinel-2 and SPOT, run by the European Space Agency and Airbus respectively.
克鲁特瓦根博士的照片来自两组卫星，分别是欧洲航天局和空中客车公司的哨兵2号和SPOT。
These peer down on the world, recording visible light and also the infrared and ultraviolet parts of the spectrum.
它们俯视着世界，记录可见光以及光谱中的红外和紫外线部分。
The images Dr Kruitwagen used amounted to around 550 terabytes of data, spanning the period between 2016 and 2018.
克鲁特瓦根博士使用的图像大约有550tb，时间跨度从2016年到2018年。
That is enough to fill more than a hundred desktop hard drives.
这足以填满一百多个台式机硬盘。
Sifting through this many pictures by eye would have been impractical.
用眼睛筛选这么多照片是不切实际的。
