Hydrogen has taken off this year as the future green fuel of choice, with governments and businesses betting big that the universe’s most abundant element can help fight climate change.

More than US$150 billion worth of green hydrogen projects have been announced globally in the past nine months. In total, more than 70 gigawatts of such projects are in development, which could require US$250 billion worth of investment by 2040, research firm Rystad Energy estimates. China, Japan and South Korea recently joined a slew of European countries setting net zero targets for carbon emissions by the middle of the century.

While most developed countries along with China and India plan to boost renewable power output, the net zero emissions targets are driving a push to find ways to decarbonize industries that cannot be electrified and depend on fossil fuels. The main targets are those sectors that use coal, oil and gas as raw materials, such as in steel-making, cement and fertilizers, and in shipping and aviation.

To meet that expected demand, powerhouse oil and gas exporters from Saudi Arabia to Australia have set out policies to develop production and export of green hydrogen. Today hydrogen is mostly extracted from natural gas or coal, called grey hydrogen, in processes that emit 830 million tons a year of carbon dioxide, according to the International Energy Agency.

Hydrogen produced from natural gas in a process which eliminates emissions by capturing and storing the emitted carbon is called blue hydrogen.

The holy grail is to extract hydrogen from water using electrolysis powered by renewable energy, “green hydrogen,” for under US$1.5 per kilogram, to make it competitive with coal, oil and gas. The key costs that have to fall to meet the sub-US$1.5 target are the cost of wind and solar power and the cost of electrolyzers, which split water into hydrogen and oxygen. Renewable power costs need to fall by around 50 percent and electrolyzer costs would need to drop by around 75 percent to meet that target, Australia’s renewable energy agency estimates.

To ship liquid hydrogen, it needs to be chilled to minus 253 degrees Celsius. Japan’s Kawasaki Heavy Industries will deliver the world’s first liquefied hydrogen carrier by early 2021.

Words to Learn 相关词汇

【充足的】chōngzú de abundant existing or available in large quantities, plentiful

【目标】mùbiāo holy grail an object or goal that is sought after for its great significance

氢在今年成为首选的未来绿色燃料，各国政府和企业都断定这种宇宙中最丰富的元素可以帮助应对气候变化。

过去9个月里，全球宣布了总额超过1500亿美元的绿氢项目。据挪威吕斯塔德能源公司估计，总共有超过70吉瓦的此类项目正在开发之中，到2040年可能会需要2500亿美元的投资。

中国、日本和韩国最近和许多欧洲国家一样确立了到本世纪中叶实现净零碳排放的目标。

时值大多数发达国家以及中国和印度都计划提高可再生能源产量之际，净零排放目标正推动各国设法使无法电气化而依赖矿物燃料的行业脱碳。

这主要针对那些以煤炭、石油和天然气为原材料的行业，例如炼钢、水泥和化肥以及航运和航空行业。

为了满足这一预期中的需求，沙特阿拉伯和澳大利亚等各大石油和天然气出口国已经制定了发展绿氢生产和出口的政策。

据国际能源署称，如今，氢主要从天然气或煤炭中提取，即所谓灰氢，提取过程每年排放8.3亿吨二氧化碳。

天然气制氢将制造过程中排放的碳捕获并储存起来，其产品被称为蓝氢。

最令人向往的是以每千克不到1.50美元的成本、使用可再生能源对水进行电解来提取氢，即“绿氢”，这样它与煤炭、石油和天然气相比才能有竞争力。

要实现绿氢须降至1.50美元以下的目标，主要成本包含风能和太阳能的成本以及电解器的成本，电解器的作用是将水分解为氢和氧。

澳大利亚可再生能源机构估计，要实现那个目标，可再生能源成本需要降低约50%，电解器成本则需要降低约75%。

液化氢必须冷却到零下253摄氏度才能装运。日本的川崎重工业公司将在2021年初以前建成全球首艘液化氢运输船。

(chinadaily.com.cn)