Carbon Footprint of Different Power Sources
Nuclear power has been touted by its promoters as an answer to concerns about increasing levels of carbon dioxide in our atmosphere and the threat of global warming. It is offered as an interim solution to lower carbon emissions from power plants while alternative energy sources are developed. The reality of carbon emissions from different power sources is very complex.
The first question about carbon emissions is what amount of carbon dioxide is emitted during the construction of the actual facility where the power will be generated and the manufacture of the components of the power generation system. The creation of concrete structures generates huge amounts of carbon dioxide. From this perspective, nuclear power plant cooling towers and containment buildings as well as hydropower dams emit the most carbon dioxide. Nuclear and fossil fuel power plants require a lot of structural steel which also emits carbon dioxide during manufacture. Solar power plants require some structural steel and also require special materials to generate power from sunlight. Their mining, refining and manufacturing process does emit some carbon dioxide. Wind farms require steel for the towers and blades but that is their only serious emitter.
The next thing to consider is the fuel cycle from mining or drilling through use to disposal of any waste generated. Mining for uranium, drilling for oil, fracking for natural gas and blow up mountains for coal all generate carbon dioxide, not to mention being highly toxic in other ways. The burning of fossil fuels in power plants generates huge amounts of carbon dioxide. Natural gas is better than oil and coal but still puts out a lot of carbon dioxide. The need to entomb nuclear waste in concrete and steel for temporary storage for at least the next thirty years will generate substantial carbon dioxide. Hydro, wind and solar power systems do not require any fuel so do not generate any carbon dioxide from a fuel cycle.
Some estimates of carbon dioxide per unit of energy generated for nuclear power and fossil fuel power plants do not include all of these sources of carbon dioxide. A recent study from a Ceedata Consultancy in the Netherlands found that when all aspects of the whole life cycle of a nuclear power plant are considered, they generate from ninety to one hundred and forty grams of carbon dioxide per kilowatt hour of electricity. For comparison, gas fired power plants which are the least emitting of the fossil fuel sources still generate around three hundred and thirty grams of carbon dioxide per kilowatt hour of electricity. This is over twice as much carbon dioxide as the worst nuclear plants so it does appear that nuclear power is definitely greener than fossil fuel power. However, wind, hydro and solar power generate from ten to forty grams of carbon dioxide per kilowatt hour of electricity. So the best nuclear power record is twice as bad as the worst sustainable alternate energy sources per kilowatt hour. All other considerations aside, nuclear power is not the answer to reducing carbon dioxide emission.
