Even before the resolution of the crisis at the Fukushima Daiichi reactor complex--a crisis that has diverted media attention from the much larger humanitarian crisis caused by last Friday's tsunami--its consequences for nuclear energy policy are rippling across the globe. It is extraordinarily premature to form conclusions about these events, although that didn't stop many from arriving at similarly hasty and under-informed conclusions in the case of last spring's Deepwater Horizon accident. Pervasive instant analysis promotes knee-jerk responses. If the nuclear renaissance that had already been slowed by the recession and financial crisis was struck a fatal blow last week, what could that mean for our energy choices in the years ahead?
Although I want to focus mainly on the potential consequences in the US, what has already transpired in Germany provides a cautionary tale. As reported Tuesday, seven nuclear power plants of similar vintage and/or design to the damaged quartet at Fukushima are being shut down, at least temporarily, as the German government reassesses its decision to extend the operating life of the country's 17 power reactors. Germany hasn't been comfortable with its nukes for some time, though I find it remarkable that 70% of the population is apparently concerned that an accident that required an epic earthquake and a tsunami to trigger could happen there, too. (The next time someone lectures you about German practicality, this would be a fine counter-example to trot out.) However odd that reaction might seem to me and others with an engineering/hard science bent, it's a reminder that nuclear risks are viewed differently than many others, perhaps because radiation is invisible and insidious in its effects. Even if the reactors are finally cooled down with no further incidents and no injuries beyond the plant personnel, who have taken great risks for the public good, we will tend to focus on how much worse the outcome could have been.
Yet shutting down those nuclear plants in Germany is not without consequences, either, as noted by the Breakthrough Institute. Germany's greenhouse gas emissions will inevitably increase, because the country is already adding renewable generation as fast as it can and must make up any shortfall from fossil fuels. After committing an estimated €120 billion ($167 billion) for solar power through 2011, based on the 20 years of feed-in tariff support existing installations will receive, Germany still gets just 2% of its annual generation from solar, compared to around 24% from nuclear. That's mainly because Germany is such an unsuitable location for solar.
What about the US? Nuclear power supplied almost 20% of the electricity generated here in 2010, compared to 45% for coal, nearly 24% for natural gas, 10% for all renewables, and less than 1% from oil. Any notion of replacing the contribution of nuclear power in the longer term would require careful consideration of the energy sources that might fill the gap--based on scale and growth potential--and what it would mean for efforts to cut greenhouse gas emissions by reducing the generation of electricity from coal, which accounted for 81% of the emissions from the electricity sector and 26% of all US emissions in 2009. As for replacing nuclear power in the short run, that's simply out of the question, unless we want to bring on a recession that would make 2009 look like a boom year.
It's not that it's impossible to imagine a US energy mix without nuclear. After all, that's what we had on a much smaller scale prior to the 1960s. We certainly have enough coal and natural gas to take up any slack, although I don't think that would be quite the desired solution of those who would be most eager for an end to nuclear power. For that matter, a combination of geothermal power and concentrated solar power (CSP), the former baseload and the latter at least dispatchable, could also fill the gap, although a geothermal build-out on that scale would provoke concerns about "induced seismicity", while CSP would be largely a regional solution or require lots of very long-distance, high voltage power lines that present massive NIMBY issues of their own. Wind power, which until last year was growing at around 40% annually, could provide 20% or more of the generating mix by 2030, but it can't substitute for nuclear's central role without far more cheap power storage than we can reasonably expect to have available by then. And while solar has great potential, especially as its cost falls, it's no better suited to delivering reliable 24/7 power than is wind, and it is starting from an even smaller level than wind's 2.3% of generation last year.
The likeliest replacement for nuclear power in the US would thus be a combination of sources similar to our current non-nuclear mix, comprised of about 55% coal, 30% gas and 15% renewables, with some help from efficiency. On the basis of the average emissions from these sources, making up for the loss of the 807 billion kilowatt-hours generated by nuclear last year would increase US greenhouse gas emissions by around 580 million tons of CO2-equivalent per year, or 10% of net US emissions in 2009. That would hardly be conducive to meeting our Copenhagen pledge to reduce emissions by 17% by 2020, but then in a non-nuclear world most such pledges would have to be considered null and void.
Barring a worst-case outcome in Japan, I don't expect a groundswell in the US if favor of abandoning nuclear power--not even for the 35 reactors of generally similar design to the ones at Fukushima. Despite that, the emissions figures I calculated above remain relevant. Without a concerted effort to build new power reactors in the next two decades, the US will be on a sure path to de-nuclearization, as 41 of the existing plants would reach the end of their lives and operating licenses--many after a full 60 years of operations--by the mid-2030s. That process could accelerate significantly if the facilities that are awaiting license extensions now face much tougher scrutiny and are turned down in significant numbers. In that case we could lose up to 10,000 MW of nuclear capacity by the end of this decade, generating roughly the same annual output as our entire current wind power capacity. There are some who are already working to make that happen, either openly or more subtly. In that context the story on MSNBC yesterday listing US nuclear reactors in order of earthquake risk was either a public service or fear-mongering, depending on your perspective.
Whether we back away from nuclear power all at once, as Germany seems poised to consider doing, or one plant at a time, the result would be much the same: increased emissions, costlier and less reliable power, at least in the near-to-medium term, and more strain on infrastructure. I still think we'll choose to include nuclear in our evolving future energy mix, particularly given the significant improvements in the technology since the Fukushima reactors were built, along with the development of new, smaller-scale nuclear power options. Yet I have to admit my confidence in that result has been shaken by the reaction to the events in Japan.