Laurence Smith - The World in 2050 - Four Forces Shaping Civilization's Northern Future

But unlike gasoline, the hydrogen is not then burned in a combustion engine. It is instead converted to electricity on-site, by feeding it into a fuel cell. Fuel cells essentially reverse the hydrolysis reaction, combining hydrogen with oxygen to create electricity and water. The newly made electricity is then used to power the car, appliance, furnace, or whatever, with the water by-product either released as vapor or recycled. Like plug-in electrics, fuel-cell cars release no tailpipe pollution or greenhouse gases (besides water vapor 120). However, they are released at the hydrogen plant, unless fossil fuels or biomass can be avoided as sources of energy or feedstocks. In principle, solar, wind, or hydroelectric power could be used to split hydrogen from a water feedstock, making the entire process quite pollution-free from beginning to end.

Sounds wonderful, and many energy experts and futurists believe that one day we will have a full-blown hydrogen economy. The ultimate dream is to use solar energy to split hydrogen from seawater, thus providing the world with an infinite supply of clean hydrogen fuel—and even some freshwater as a bonus—with no air pollution or greenhouse gases. But nothing like that will be in place by 2050.

Years of research are needed to resolve a rat’s nest of challenges concealed within the previous two paragraphs, with major technology advances and cost reductions necessary in all areas. 121Basic research in hydrogen manufacture, transport, and fuel cells is still lacking. The cost of making a fuel-cell vehicle is extremely high. A completely new physical infrastructure is required, including manufacturing plants, pipelines, distribution and bottling centers, and filling stations. Hydrogen is explosive, so there are many safety issues to be resolved, like how to safely pack enough of it into a vehicle to drive three hundred miles, comparable to vehicles today. One way is to use highly pressurized hydrogen, but the collision safety of ten-thousand-psi tanks remains unproven. Early hydrogen supplies are all but certain to be made from fossil fuels, and thus will help little with reducing carbon emissions.

In light of these challenges, most experts agree that a hydrogen economy lies at least thirty to forty years in the future, at which point hydrogen fuel-cell cars might possibly be the new “next-generation” technology that plug-in hybrids are today. Under the conservative ground rules of our thought experiment, we will assume the world will not convert to a hydrogen economy by the year 2050.

Unlike hydrogen, biofuels offer a quicker solution to the liquid-fuels problem. Like gasoline, they are refined hydrocarbons that are burned in an internal combustion engine. They use the same filling stations and, with only slight modifications, the same car and truck engines of today. 122The only real difference between biofuels and current fuels is that they are made from contemporary organic matter rather than ancient organic matter, and are somewhat cleaner. They emit similar levels of carbon dioxide from the tailpipe as gasoline or diesel, but fewer sulfur oxides and particulates. In principle, when biofuel crops grow back they draw down a comparable amount of new carbon from the atmosphere, thus offsetting their emission of greenhouse gas, but this does not take into account the added emissions of growing, harvesting, and transporting the crop. The biggest appeal of biofuels, therefore, is that they offer a domestic or alternative liquid-fuel source to oil, and potentially less greenhouse gas emission, depending on how efficiently the biofuel can be produced.

The most common biofuel today is ethanol made from corn (in the United States), sugarcane (Brazil), and sugar beets (European Union). Making ethanol is essentially the ancient art of fermenting sugars to make alcoholic drinks, meaning that corn-based car fuel is very similar to moonshine. It is commonly mixed with gasoline, and in Brazil, cars run on flex-fuel mixtures containing up to 100% ethanol. Ethanol has higher octane than gasoline and for this reason was used in early racing cars. In fact, when cars were first being developed about a century ago, their makers strongly considered fueling them with ethanol. 123

The world’s two largest ethanol producers are the United States and Brazil, together producing more than ten billion gallons per year. That may sound like a lot, but it’s less than 1% of the liquid-fuels market. The good news is that Brazil is becoming quite expert at making sugarcane ethanol. Production is rising rapidly and is expected to double by 2015. 124Sugarcane plantations are expanding and, contrary to popular belief, represent little deforestation threat to Amazon rain forests because they are found mostly in the south and east of Brazil. 125Improved agricultural practices have more than doubled the ethanol yield per unit area, and new genetic methods called marker-assisted breeding suggest further increases of up to 30% in the future. The price Brazilians pay for ethanol has steadily fallen for the past twenty-five years even as the price paid for gasoline has gone up. 126In 2008, for the first time in history, Brazilians bought more ethanol than gasoline. 127

The United States is also ramping up ethanol production. The 2007 Energy Independence and Security Act calls for a tripling of U.S. corn-based ethanol production by 2022, a goal reaffirmed by the Obama administration in 2010. Ethanol also comprises a large part of the U.S. Department of Energy’s official goal to replace 30% of gasoline consumption with biofuels by 2030. The European Union hopes to derive a quarter of its transport fuels from biofuels by the same year. 128

Unfortunately, there are tremendous differences in production efficiency among the different plant crops used to make ethanol. Sugarcane is a high-value feedstock, yielding up to eight to ten times the amount of fossil-fuel energy needed to grow, harvest, and refine sugarcane into ethanol. Corn-based ethanol, in contrast, is terribly inefficient, usually requiring as much or more fossil fuel in its manufacture as is delivered by the final product. Therefore the greenhouse gas benefit of corn ethanol over oil is negligible. 129While often pitched otherwise, American subsidies for it are for objectives other than greenhouse gas reduction. For that goal, a far smarter biofuel investment would be production of sugarcane ethanol in the Caribbean, a potential “Middle East” for ethanol export to the United States. 130

Another problem is that current technology requires ethanol to be made from simple sugars and starches, putting biofuel crops in direct competition with food crops. The U.S. corn ethanol program was widely blamed in 2007 for a worldwide rise in food prices, because it subsidized farmers to plant fields with corn for fuel rather than with wheat and soybeans for food. 131This notion that biofuels threaten global food supply reared up again in 2008 in response to a series of food riots in Haiti. 132While this fear is probably overblown—the share of arable land currently used for biofuel production is only a few percent, and geographic models indicate adequate land does exist for the coexistence of energy and food crops 133—it is nonetheless disturbing to imagine, in a 2050 world with half again more people than today, converting large swaths of prime farmland to feed cars instead of people.

An attractive alternative would be making ethanol from cellulose, extracted from low-value waste and woody material. Indeed, to make sense any large-scale conversion to biofuels must include cellulosic technology. 134Cellulose is found in waste products like sawdust and cornstalks, or in grasses and woody shrubs that grow on marginal land not suitable for food crops. It is also the only way to achieve large greenhouse gas reduction through biofuels: Because cellulose requires little or no mechanical cultivation, fertilizers, or pesticides, the amount of fossil fuel needed to produce it is greatly diminished.