The End of Doom (34 page)

The US company TerraPower's traveling wave reactors are designed to run on what is now essentially nuclear waste. The unique fuel cycle of traveling wave reactors use U-238, often referred to as depleted uranium. The United States has more than 700,000 metric tons of depleted uranium in storage. The amazing fact is that burning those stores of depleted uranium in traveling wave reactors could supply the United States with electricity for thousands of years. TerraPower estimates that burning global stores of depleted uranium (about 1.5 million metric tons) could supply 80 percent of the world's population with the amount of electricity Americans use per capita today for the next thousand years.

How do these reactors work? A traveling wave needs to be ignited only once, using just a bit of U-235 or plutonium to jump-start a chain-reaction wave of neutrons that continuously converts U-238 into plutonium-239. The traveling wave reactor also reduces nuclear weapons proliferation risks, since its fuel cycle would eliminate the need for numerous uranium processing plants. As Charles W. Forsberg, executive director of the Nuclear Fuel Cycle Project at the Massachusetts Institute of Technology, has quipped, the traveling wave fuel cycle “requires only one uranium enrichment plant per planet.”

The plutonium burns itself up as it sustains a further chain reaction by transforming depleted uranium into more plutonium. In other words, a traveling wave reactor produces plutonium and uses it up at once, which means that, unlike fuel in conventional reactors, there is very little left over that could be diverted for weapons production. The traveling wave moves through the reactor core at a rate of about a centimeter per year, somewhat like a cigarette burns from tip to filter. Or think of it as two waves, a breeding wave that produces plutonium which is followed close behind by a burning wave that consumes the plutonium. The core is cooled with liquid sodium and the heat is drawn off to produce steam to drive electric generators. TerraPower expects that traveling wave reactors will be sealed and will operate for fifty to a hundred years without refueling or removing any fuel from the reactor.

One of the bitter jokes popular among frustrated aficionados of nuclear fusion power is that practical fusion energy is only thirty years away and always will be. In October 2014 researchers at aerospace giant Lockheed Martin confidently announced that they had made a technological breakthrough that would enable them to build and test a prototype compact fusion reactor in a year and begin deploying them in ten years. Essentially, the Lockheed researchers claimed to have figured out how to confine the hot plasma needed for fusion in a much smaller and less finicky magnetic bottle than the conventional tokamak reactor. How much smaller? Ten times smaller, one that would fit in the back of a large truck. Such a 100-megawatt compact fusion reactor could supply enough electricity to run a small city of 100,000 people. It might even be used to power aircraft. The reactor could run for a year by fusing fifty-five pounds of deuterium and tritium to produce the heat needed to drive generators. Fusion reactors produce much less radioactive waste than conventional fission reactors and no greenhouse gases to warm the planet's atmosphere.

Why Not Deploy Current Renewable Power Technologies Now?

“We have the tools—the technologies, the resources, the economic models—to deliver cost-effective climate solutions at scale,” testified K. C. Golden of the US-based NGO Climate Solutions before the Senate Committee on Environment and Public Works in July 2013. Friends of the Earth issued a similar statement in September 2013: “We have the technology we need [to address climate change] and we know what needs to happen. We just need to get politicians to do it.” Tove Maria Ryding, coordinator for climate policy at Greenpeace International, sounded the same note in 2012: “We have all the technology we need to solve the [climate] problem while creating new green jobs.”

The implication is that humanity could deploy a suite of currently available zero-carbon energy production technologies and energy efficiency improvements to avert the impending climate catastrophe. And the idea has been around for a while. Back in 2008, Al Gore urged America “to commit to producing 100 percent of our electricity from renewable energy and truly clean carbon-free sources within 10 years,” a goal that he pronounced “achievable, affordable and transformative.” His plan was possible, he explained, because the price of the technologies needed to produce no-carbon electricity—solar, wind, and geothermal—were falling dramatically.

As it happens, America did not take up the former vice president's challenge. In 2014, solar, geothermal, and wind energy generated 0.46, 0.39, and 4.28 percent, respectively, of electric power in the United States.

Was Gore right seven years ago? And are the folks at Greenpeace, Friends of the Earth, and Climate Solutions right now that the no-carbon energy technologies needed to replace fossil fuels are readily available and ready to go?

Not really, concludes a November 2013 report, “Challenging the Clean Energy Deployment Consensus,” by the Washington, DC-based Information Technology and Innovation Foundation (ITIF). Such plans, the study argues, “are akin to attempting large-scale moon colonization using Apollo-age spacecraft technology.” Such a feat may be technically feasible, but only at vast expense.

Think of the issue this way: Would you rather drive a 1913 Model T Ford or a 2013 Ford Fiesta? They cost about the same amount of money in inflation-adjusted dollars. One way to interpret the ITIF report is that the advocates of immediately deploying current zero-carbon energy production technologies are essentially arguing that we should now all be driving Model T Fords.

To get some idea of what would be involved in “repowering” America using only the currently available zero-carbon technologies, let's delve into one of the more ambitious of the studies that the ITIF folks criticize. In a 2011 paper, the Stanford engineer Mark Jacobson and the University of California at Davis transportation researcher Mark Delucchi calculated what it would take to produce all the energy (not just electric power generation) to fuel the entire world using zero-carbon sources by 2030. They also calculate what renewable sources of energy would be needed to power just the United States. They conclude that this would require 590,000 5-megawatt wind turbines, 110,000 wave devices, 830 geothermal plants, 140 new hydroelectric dams, 7,600 tidal turbines, 265 million rooftop solar photovoltaic systems, 6,200 300-megawatt solar photovoltaic power plants, and 7,600 300-megawatt concentrated solar power plants.

Let's adjust those figures to take into account the fact that we currently use 40 percent of primary energy to generate electricity. Making the heroic assumption that Americans will consume no more electricity in 2030 than they do today, what would it take to “repower” the country's 1,000-gigawatt electric generation sector entirely in zero-carbon renewable energy sources? Keep in mind that the total asset value of the entire US electrical system, including generation, distribution, and transmission, amounted to $800 billion in 2003.

Well, first we would have to install 15,000 new wind turbines, 155 solar photovoltaic, and 190 concentrated solar power plants each year. In 2012, the US wind industry installed a record 13 gigawatts of rated generating capacity; construction of 15,000 5-megawatt turbines annually for the next sixteen years entails a fivefold jump in the installation rate. Building 13 gigawatts cost $25 billion, which implies an increase to $125 billion annually, reaching a total cost over the next sixteen years of $2 trillion. And that's just for wind power.

In 2012, the world's largest solar photovoltaic plant came online in Arizona at Agua Caliente. That facility, rated at 250 megawatts of generation capacity, cost $1.8 billion to build. Achieving the zero-carbon repowering goal implies constructing 155 of these each year for the next sixteen years. The costs would amount to roughly $280 billion annually, for a total of $4.5 trillion. The United States is also home to the world's largest concentrated solar power plant at Ivanpah, California. That 372-megawatt plant cost $2.2 billion to build, which implies spending about $440 billion annually for 190 such plants, adding up over sixteen years to roughly $7 trillion.

That's just to build enough
rated
zero-carbon generation capacity to replace what we have now. As the ITIF study makes clear, most renewable power sources are highly variable in their production. The deploy-now crowd hopes that somebody will invent some way to store electricity so that it could make up for shortfalls when the sun doesn't shine or the wind fails to blow.

A 2013 study analyzed by the ITIF researchers solves this renewable energy storage problem by oversizing—that is, by building two to three times more generating capacity than would be necessary if they could operate near their rated capacity all of the time. This suggests that at the low end of this estimate would raise the estimated costs in the repowering scenario by 2030 to $4 trillion for wind generation and to more than $23 trillion the total solar portion.

Admittedly my preliminary rough calculations assume that costs for constructing zero-carbon energy sources do not fall over the next sixteen years. The price of the Model T Ford, introduced in 1908 at the price of $850 ($22,000 in 2013 dollars), fell from $550 ($13,000 in 2013 dollars) to $260 ($3,500 in 2013 dollars) by its last year of production in 1927. Assuming that the costs of installing current versions of zero-carbon energy production technologies fell as much immediately, the total costs for would still amount to roughly $7 trillion by 2030.

The ITIF analysis alternatively adds up all of the costs in the Jacobson/Delucchi paper to estimate that weaning Americans off fossil fuels entirely by 2030 would add up to a total of $13 trillion—that is to say, 5 percent of each year's GDP over the next sixteen years. The upshot is that this repowering would cost each American household an additional $5,664 per year until 2030.

Are Americans really willing to shell out that much cash for zero-carbon energy? The ITIF report observes that a 2011 poll found that Americans were willing to pay just under $10 per month ($120 per year) more for electricity generated by renewable sources. In addition, half of Americans can choose to pay about 10 percent more to purchase electricity generated from renewable sources, but only 1 percent actually do so.

These calculations are just for the United States. Somewhere around 1.3 billion people around the world still do not have access to electricity. Taking the Jacobson and Delucchi figures for the world, the total cost to completely eliminate fossil fuels by 2030 would amount to $100 trillion—that is to say, 8 percent of global annual GDP. The global cost per household per year would amount to $3,571. The nearly 3 billion people who live on less than $2,000 per year simply cannot pay the prices needed to deploy current versions of renewable power technologies.

Despite the foregoing analysis, technological innovation and competitive markets may yet come to the rescue during the coming decades.

Unlimited Free Solar Power?

“Despite the skepticism of experts and criticism by naysayers, there is little doubt that we are heading into an era of unlimited and almost free clean energy,” the Stanford technology maven Vivek Wadhwa declared in
The
Washington Post
in September 2014. The technology that most inspires his enthusiasm is solar energy—and while solar isn't close to “almost free” yet, it is indeed getting cheaper. The prices of solar photovoltaic (PV) modules have fallen steeply by more than 80 percent since 2008.

This trajectory seems to be following Swanson's Law, named for Richard Swanson, the founder of US solar-cell manufacturer SunPower. Swanson suggested that the cost of the photovoltaic cells falls by 20 percent with each doubling of global manufacturing capacity. The pattern is a product of constantly improving manufacturing processes: more automation, better quality control, materials reduction, and so forth.

But how plausible is Wadhwa's prediction that solar power will be unlimited and nearly free? To get a handle on solar's future, let's look at a measure called the
levelized cost of energy
. This takes into account the capital costs, fuel costs, operations and maintenance costs, debt and equity costs, and plant utilization rates for each type of electric power generation. Many different groups have tried to calculate and compare the levelized costs for building, operating, and financing coal, natural gas, nuclear, hydro, solar, wind, geothermal, and biomass plants.

Let's start with the levelized cost analysis that is the most bullish with respect to solar photovoltaic. In September 2014, the financial advisory firm Lazard reckoned that the levelized unsubsidized cost of utility-scale solar PV is as low as $72 per megawatt-hour. (A megawatt-hour is roughly equivalent to the amount of electricity used by 330 houses during one hour.) Lazard projects that these costs will drop to $60 per megawatt-hour by 2017. Meanwhile, the low end of natural gas generation is now $61 per megawatt-hour; for coal generation, it's $66 per megawatt-hour; and for nuclear, it's $124 per megawatt-hour. With the current US tax breaks, the low-end solar PV utility-scale costs is $56 per megawatt-hour. Even so, George Bilicic, a vice chairman of Lazard, concluded that utilities “still require conventional technologies to meet the energy needs of a developed economy, but they are using alternative technologies to create diversified portfolios of power generation resources.”

Every couple of years the Electric Power Research Institute, a nonprofit think tank sponsored by the electric power generation industry, issues a report on the levelized cost of energy for various power generation technologies. Its
Integrated Generation Technology Options 2012
report calculates the low-end levelized cost for solar PV next year at $107 per megawatt-hour. For natural gas, coal, and nuclear, the low-end costs are $33, $62, and $85 per megawatt-hour, respectively.