According to a new report released by the United Nations Economic Commission for Europe (UNECE), nuclear power generates the least carbon dioxide emissions over its life cycle compared to any other electricity source.
The report examines the emissions emitted by various electricity sources throughout their life cycle like coal, natural gas, oil, hydropower, solar technologies, wind, coal with carbon capture and storage (CCS), natural gas with CCS, nuclear power. The analysis shows nuclear has the lowest carbon footprint, measured in grams of CO2 equivalent per kilowatt-hour (kWh) of electricity than any other technology.
Among all electricity sources, coal turns out to have the highest scores, with a minimum of 751 g CO2 equivalent/ kWh and a maximum of 1095 g CO2 eq./kWh. If fitted with a carbon capture facility, and accounting for the CO2 storage, the score changes to 147 – 469 g CO2 eq./kWh.
A natural gas power plant can emit between 403 – 513 g CO2 eq./kWh from a life cycle perspective, and anywhere between 49 and 220 g CO2 eq./kWh with CCS. The model also counts for methane leakage at the extraction and transportation phases.
On the renewables side, solar releases 27 to 122 g CO2 eq./kWh for concentrated solar power (CSP), and 8.0 – 83 g CO2 eq./kWh for photovoltaics. Wind’s greenhouse gas emissions vary between 7.8 and 16 g CO2 eq./kWh for onshore, and 12 and 23 g CO2 eq./kWh for offshore turbines. Compared to coal, for example, nuclear power emits a mere 5.1 – 6.4 g CO2 eq./kWh.
Other variables are also examined in the report like ionizing radiation and human toxicity. Another finding shows that coal power is a potentially significant source of radioactivity, as coal combustion may release radionuclides like radon 222 or thorium 230.
CSP plants may score high in carcinogenic effects due to emissions of chromium VI linked with the production of chromium-containing stainless steel, required in significant quantities in solar field infrastructure.
The UNECE report points out nuclear as the power source with the lowest greenhouse gas emissions and coal as the fossil fuel having the highest scores in several variables like emissions, human toxicity, and freshwater eutrophication. Such scientific analysis could support countries when making decisions on what energy sources to develop in the future when it comes to saving emissions and preserving people’s health and the environment.