For about a decade now, nuclear boosters have been telling us that a “nuclear renaissance” is underway thanks to the advent of cheaper, safer and faster-built “third-” and “fourth-generation” reactors. Their ranks have been swelled lately by green champions of nuclear power like George Monbiot, who has recently embraced nuclear energy as an alternative to fossil fuels in the quest to mitigate climate change. Anti-nuke activists like Helen Caldicott have responded with dire warnings of nuclear apocalypse and radiation-induced cancer (see their exchange on a recent episode of Democracy Now!).

But for all its moral urgency, this debate usually ignores the economics of nuclear power. It is economic factors like costs, supply chains, financing and profitability that will determine our future energy mix. And so far, the dollars and cents calculations for nuclear power just do not add up.

The argument for nukes gets even weaker when one considers the compressed time frame of climate change: carbon emissions must drop sooner and faster than the long, slow, costly process of building new nuclear plants would allow. The boosters of nuclear power, including greens like Monbiot, seem to forget the reactors don’t build themselves. They are built and operated by specific institutions under concrete economic circumstances like the price of capital, special metals, insurance and the availability of skilled labor. Once the economic arguments get to that level of specificity, the viability of atomic power falls apart.

Moreover, casting a nuclear renaissance as the panacea for climate change is dangerous because it threatens to delay the shift to clean energy. Continually pushing nukes has opportunity costs; every dollar, euro or RMB spent on nuclear power is one not spent on clean technology like wind, solar, hydro or tidal kinetics.

First, a bit of history: The initial wave of nuclear power reached its zenith after the Arab oil embargo of 1973. That political and economic shock sent many developed economies on a reactor construction spree. The logic here was fundamentally geostrategic, not economic: better to have power from nukes that operated at a loss and were subsidized by the rest of the economy than to have your whole economy collapse because you could not import oil. In particular, Japan and France went nuclear; France converted the majority of its electrical supply from fossil fuels to nuclear.

But these second-generation reactors, which make up the majority of the world’s current fleet of 443 nuclear power stations, soon proved to be prohibitively expensive and slow to build. After the Three Mile Island accident, hundreds of planned plants in the United States were canceled and construction around the world slowed. Bankruptcies associated with nuclear power rose, and investors began to turn away from it.

Even in France and Japan, building new reactors mostly halted. France became the most nuclear-powered country in the world, in part because its system is fundamentally socialized; the various companies associated with construction and operation of nuclear plants never had to turn a profit and managed to offload most of their debts onto the public. Japan’s reactors are also heavily subsidized.

In the US and the UK cost overruns on nuclear plants helped bankrupt several utility companies. In the US these losses helped usher in the debacle of energy deregulation in the mid-’90s that saw rising rates and power blackouts in California. When the UK began privatizing utilities its nuclear reactors were so unprofitable they could not be sold. Eventually in 1996, the government gave them away. But the company that took them over, British Energy, had to be bailed out in 2004 to the tune of 3.4 billion pounds.

It was around the turn of the millennium that people like British Prime Minister Tony Blair and Senator Pete Domenici of New Mexico began championing the second coming of the atom. Yes, they agreed, the critiques of the old equipment were correct. But the new third- and fourth-generation reactors would be safe, cheap and quick to build.

In February 2002, the Bush administration tried to jump-start nuclear construction with its “Nuclear Power 2010 program,” a package of subsidies and streamlined planning procedures. It was expected that these incentives would lead to at least one “Generation III+ unit” being operational by 2010.

It is true that Generation III reactors are safer than older reactors like the GE MAC 1 at Fukushima, Vermont Yankee and other plants around the world. But the new technology is not cheap, nor is it quick to construct. After a decade in which the federal government did all it could to boost this new version of nuclear power, only one Generation III+ reactor project has even been approved. Work on it has just begun in Georgia, and already there are conflicts between the utility, Southern Company and the Nuclear Regulatory Commission. Moreover, this project is going forward only because it is in one of the few regions of the United States (the Southeast) where electricity markets were not deregulated. That means the utility, operating on cost-plus basis, can pass on to rate-payers all its expense over-runs.

Another US reactor is being assembled at the Tennessee Valley Authority’s Watts Bar plant. But construction on this second-generation, Westinghouse-designed Pressurized Water Reactor, designed in the 1960s, was begun in 1972. After long delays, the unit should be up and running in 2012.

In Western Europe the situation is very similar. Only two Generation III+ reactors are under construction. The plant closest to completion is Olkiluoto 3 in Finland. This 1,600-megawatt European Pressurized Reactor (EPR) is being built by Areva, the French government-controlled nuclear construction firm. The reactor was scheduled to take four years and cost about $5 billion. But now construction will take at least eight years and is 68 percent over budget, at a projected final cost of $8.4 billion. Some fear that the Olkiluoto 3 could bankrupt its owner, TVO. The other EPR under construction is in Flamanville, France. It began in 2007 and is now two years late and at least 50 percent over budget. In the best-case scenario, it will open in 2012.

In the United States, the Nuclear Regulatory Commission’s review process to certify the safety of the EPR is itself two years behind schedule.

There are sixty-four, mostly old-style nuclear plants under construction worldwide, and most of these are in Asia. Sixty-plus reactors might sound like a lot, but when you compare that to the overall size of the world appetite for energy, it’s not much. If all of these nuclear power plants are completed they will add 62.56 gigawatts of capacity, which is less than one-third of already-existing wind capacity worldwide, which was at 196.63 gigawatts at the end of 2010.

Of the sixty-four nuclear plants under construction worldwide, twenty-seven are in China and eleven are in India. China already has thirteen operating reactors, which produce less than 2 percent of its total electricity. India gets a little more than 2 percent of its electricity from existing nuclear plants. If China finishes building all of the nuclear plants under construction there, nuclear power will still only account for 9 percent of the country’s total electricity.

Even in China wind is outpacing nuclear power. China’s total installed wind capacity, which has been roughly doubling every year for the past several years, was 44.7 gigawatts at the end of 2010. The Chinese wind sector is set to reach as much as 200 gigawatts by 2020, according to the China Wind Power Outlook 2010 report. That figure dwarfs the 10.06 gigawatts of nuclear power online now, which will increase by only 27 gigawatts if all of China’s planned plants get built. “China is not going nuclear they way France did the 1970s,” says Stephen Thomas, professor of business at the University of Greenwich in the UK.

An analysis by economist Mark Cooper, senior fellow for economic analysis at the Vermont Law School, found that adding 100 new reactors to the US power grid would cost $1.9 to $4.1 trillion. And the problem is not simply this direct investment.

“Once a utility embraces a huge nuclear project, their finances are completely tied up. The company’s management is completely tied up. They begin to look at all other alternatives—efficiency and renewables, which you can buy in smaller bites—as threats to their big project,” said Cooper. “They become very hostile to sensible policy. And then you end up with extremely expensive power.”

In a comparative analysis of US states, Cooper found that the states that invested heavily in nuclear power had worst track records on efficiency and developing renewables than those that did not have large nuclear programs. In other words, investing in nuclear technology crowded out developing clean energy. That’s dangerous because the primary problem facing clean alternative energy is the “price gap”—they are still more expensive than fossil fuels. As I’ve outlined in these pages previously (see “The Big Green Buy”), economies of scale, along with subsidies and planning, will help close this price gap.

Only when clean technologies—like wind, solar, hydropower and electric vehicles—are cheaper than other options will global capitalism make the switch away from fossil fuels. The good news is that clean tech is catching up. An authoritative study by the investment bank Lazard Ltd. found that wind beat nuclear and that nuclear essentially tied with solar. So the race is tight. The Worldwatch Institute reports that between 2004 and 2009, electricity from wind (not capacity but actual power output) grew by 27 percent, while solar grew by 54 percent. Over the same time, nuclear power output actually declined by half a percent.

Another danger with pursuing the myth of a nuclear renaissance is the overall timing of climate change. Science tells us that aggressive emissions reductions need to start immediately. Emissions need to peak by 2015 and then decline precipitously if we are to avoid catastrophic climate change.

A massive industrial-scale build out of fourth-generation nukes—the ones that are supposed to be safe, cheap and easy to build—would arrive too late to stave off climate change’s tipping points. The US Department of Energy (DoE), a major booster of all things nuclear, gives 2021 as the earliest possible date for a fourth-generation nuclear plant to open. Keep in mind, no American nuclear plant has yet been built on time or within budget, so the DoE’s forecast is very optimistic.

Nuclear power is simply not going to sweep in over the next handful of years and change the energy mix and save us from these tipping points. The catastrophically tight timeframe of climate tipping points means we must scale up actually existing clean technology. That will take massive investments and serious planning—but that project has already begun. Alternatives are slightly cheaper than nukes, come online faster and are growing robustly.

In other words, nuclear power is not only physically dangerous; it is also economically wasteful and slow, especially when built in market economies. Quite simply, it is a stupid way to address climate change.

As the wags like to say: “Nuclear power is the energy source of the future. And it always will be.”