Nuclear power: False climate change prophet?
21 Jul, 2008 09:31 am
A new study reveals that nuclear power is not as clean as the industry claims.
Which side is right?
One new study published in the August 2008 issue of the peer-reviewed journal Energy Policy attempts to answer this question. It screened 103 lifecycle studies of greenhouse gas equivalent emissions for nuclear power plants to identify a subset of the most current, original, and methodologically rigorous studies. The study found that while the range of emissions for nuclear energy over the lifetime of a plant reported was from 1.4 grams of carbon dioxide equivalent per kWh (gCO2e/kWh) to 288 gCO2e/kWh, the mean value was 66 gCO2e/kWh.
The frontend component of the nuclear fuel cycle (uranium mining, milling, and enrichment) is responsible for 38 percent of equivalent emissions. Decommissioning and plant operation, including the use of fossil-fueled generators to backup nuclear plants when they offline for servicing, account for 35 percent. The backend of the fuel cycle, which includes storing spent fuel and fuel conditioning, account for 15 percent of the emissions, and plant construction is responsible for 12 percent.
This average—66 grams of carbon dioxide for every kWh—is shockingly high compared to what the nuclear industry has reported. It also shows, conclusively, that nuclear energy is in no way “carbon free” or “emissions free,” and that nuclear power is worse than the equivalent carbon emissions over the lifecycle of renewable and small scale distributed generators (although it is an improvement over oil-, coal-, and natural gas-fired generators).
To provide just a rough estimate of how much equivalent carbon dioxide nuclear plants emit over the course of their lifecycle, a 1,000 MW reactor operating at a 90 percent capacity factor will emit the equivalent of 1,427 tons of carbon dioxide every day, or 522,323 metric tons of carbon dioxide every year. Nuclear facilities were responsible for emitting the equivalent of some 183 million metric tons of carbon dioxide in 2005. Assuming a carbon tax of $24 per ton—nothing too extreme—and that 1,000 MW nuclear plant would have to pay almost $12.6 million per year for its carbon-equivalent emissions. For the global nuclear power industry, this equates to approximately $4.4 billion in carbon taxes per year.
Researchers in the United Kingdom conducted lifecycle analyses for 15 separate distributed generation and renewable energy technologies found that all but one, solar photovoltaics (PV), emitted much less gCO2e/kWh than the mean reported for nuclear plants. In an analysis using updated data on solar PV, researchers in the United States found that current estimates on the greenhouse gas emissions for typical solar PV systems range from 29 to 35 gCO2/kWh.
This has two very important insights for the current debate about nuclear power and climate change.
First, nuclear power plants would not benefit directly from a global carbon tax or a carbon cap-and-trade system. While the nuclear industry would be penalized less than fossil-fueled generators, the carbon equivalent emissions from uranium mining operations, enrichment facilities, plant construction, decommissioning, and spent fuel storage are significant. Any type of extra cost for carbon-equivalent would increase, absolutely, the price of these elements of the nuclear fuel cycle, and would thus make nuclear power more expensive.
Second, while it may be unfair to compare baseload sources such as nuclear to intermittent or non-dispatchable sources such as wind and solar PV, if these numbers are correct, then offshore wind power has less than one-seventh the carbon equivalent emissions of nuclear plants; large-scale hydropower, onshore wind, and biogas, about one-sixth the emissions; small-scale hydroelectric and solar thermal one-fifth. This makes these renewable energy technologies seven-, six-, and five-times more effective on a per kWh basis at fighting climate change.
Put simply, investments in nuclear power are much worse at fighting climate change than pursuing wind, solar, and other small-scale power generators. Policymakers would be wise to embrace these more environmentally friendly technologies if they are serious about producing electricity and mitigating climate change.
For further reading:
Barnaby, Frank and James Kemp. 2007. Secure Energy? Civil Nuclear Power, Security, and Global Warming (Oxford: Oxford Research Group, March, 2007).
Fthenakis, V.M., Kim, H.C., and Alsema, M. 2008. “Emissions from Photovoltaic Life Cycles.” Environmental Science and Technology 42, 2168-2174.
Pehnt, Marin. 2006. “Dynamic Lifecycle Assessment of Renewable Energy Technologies.” Renewable Energy 31 (2006), pp. 55-71.
Sovacool, Benjamin K. 2008. “Valuing the Greenhouse Gas Emissions from Nuclear Power: A Critical Survey,” Energy Policy 36 (8) (August), pp. 2940-2953.
Sovacool, Benjamin K. 2008. “Nuclear Power is a False Solution to Climate Change,” The Jakarta Post (July 15), p. 6.