资源环境科技发展态势分析平台

Steam-electric power dominates global electricity production. Mitigating its environmental burdens relies on quantifying them globally, on a high resolution. Here, with an unprecedented combination of detail and coverage, the Rankine cycle was individually modelled for >21 000 geocoded steam-electric generating units globally. Accounting for different cooling systems and fuels enabled the calculation of three major environmental stressors on a generating unit level. Geographical, chronological, and technological patterns are examined, as are trade-offs and improvement scenarios. Greenhouse gases (GHG) emissions from young (>2000) Chinese coal-fuelled generating units are equal to the sum of GHG emissions from all steam-electric power plants of all ages in the U.S. and Europe, and occupy 5% of all GHG emissions from the entire global economy. Twenty-four per cent of freshwater consumed from steam-electric power originates from nuclear power units from the 1970s/1980s, mainly in the U.S. and Europe. One per cent of steam-electric generating units is responsible for 50% of global heat emissions to freshwater. The median carbon intensity of Indian coal-fired units (≥50 MW) is 7%–16% higher than that in any other region globally. As concerns GHGs, technology-related efficiency differences (Rankine cycle, cooling system) play a small role compared to the fuel, which dominates the carbon intensity (GHGs/GJ el.). With the highest shares of cogeneration, 1 GJ electricity from tower-cooled coal units in Russia consumes on average 8%–49% less freshwater compared to respective units globally. There is a small margin for improvement based on alternative steam-electric technologies: retiring inefficient units and replacing their demand by ramping up more efficient ones with the same fuel, within the same country results in, respectively, ~1%, 6%, and 11% fewer GHG emissions, freshwater consumption, and heat emissions globally. The full environmental benefits of completely retiring old units (<1970) consist of 9% fewer GHG emissions, 7% less freshwater consumed, and 18% fewer thermal emissions globally.