Green energy's big challenge: the daunting task of scaling up

Posted: 2 February 2011

Author: David Biello

To shift the global economy from fossil fuels to renewable energy will require the construction of wind, solar, nuclear, and other installations on a vast scale, significantly altering the face of the planet. Can these new forms of energy approach the scale needed to meet global energy demands? asks David Biello of Yale e360.

From the dust-blown steppes of Inner Mongolia to the waters off Shanghai, China installed more wind turbines in the first half of 2010 than any other country — 7,800 megawatts of potential power production, or more than the United States, the European Union, and India combined. In fact, in northeast China alone, autumn and winter winds now produce some 17 billion kilowatt-hours of electricity, roughly 5.5 percent of the total power generation in the region. That’s up from 534 million kilowatt hours just five years ago.

Wind turbines supply power to Urumqi
Wind turbines supply power to Urumqi, the capital of China's Xinjiang Autonomous Region. Photo credit: China Energy Conservation Investment Corp

But despite this rapid progress, wind energy still only generates a tiny fraction of China’s electricity. Indeed, even with aggressive government backing and green energy mandates, such “new energy” — including wind, solar, nuclear power plants, and biomass — accounts for less than 3 percent of China’s electricity production, compared to more than 70 percent provided by coal, which produces roughly 3 metric tons of carbon dioxide for every metric ton of the dirty, black rock burned. And as China’s economy continues to expand at a dizzying rate for the foreseeable future, wind and other renewable sources of energy will not even be able to keep pace with new demand, meaning fossil fuel burning will continue unabated.

This is hardly unique to China. In the U.S., electricity produced from the breeze has increased 13-fold in the past decade, yet still only provides 2.3 percent of the country’s electricity — compared to just under 50 percent provided by burning coal. Even Denmark, which has done more than any other country to boost wind power, struggles to integrate an intermittent generating resource into a grid whose customers expect the lights or the television to come on whenever they flick the switch.

As the world attempts to wean itself from fossil fuels — a result of the converging desires to combat climate change, improve energy security, and create green jobs — renewables such as the sun, wind, water, and hot rocks will play a larger role. So will energy sources, such as nuclear and natural gas, that are cleaner than the current favorites, coal and oil. The question is: Can any of these resources — or even all of them put together — begin to approach the scale needed to transform the world’s energy supply?

And even if the world’s economies can muster the resources and willpower to wean themselves off fossil fuels, how many decades will it take? And can we move fast enough to stave off the potentially calamitous effects of climate change?

“Renewables are growing at fantastic rates compared to conventional resources,” says David Rogers, general manager for climate change at the oil giant, Chevron. But “while it’s growing like gangbusters, it’s starting from such a small base that by 2030 it still takes a small part of the energy space.”

To meet a proliferating set of international goals, such as Germany’s plan to derive 80 percent of its electricity from renewable sources by 2050, will require completely changing the present energy mix. Despite more than 21,000 wind turbines and 13 million square meters of solar installations, Germany still gets more than 50 per cent of its electricity from burning fossil fuels, including lignite, the most polluting form of coal.

Lignite power station, Germany
Niederaussem brown coal (lignite) power plant, near Cologne in North-Rhine Westphalia, Germany. According to a WWF study, this power plant is number ten of the worst climate polluters in Europe. Photo © Andrew KERR / WWF-Canon

“In some real sense, we need to replace all of the power-producing infrastructure that we have today within 30 or 40 years,” says engineer Saul Griffith of California-based Other Lab, an engineering and design firm working on renewable energy projects, among other pursuits. “The options that we have that are non-carbon [dioxide] producing are nuclear power, solar power at a very large scale, wind power at a very large scale, and geothermal at a very large scale — and then perhaps biofuels or carbon sequestration on existing power plants.”

If the world makes the transition to renewable energy, wind turbines will become a common feature of many landscapes. In fact, at the global level, in order to shift away from a world that gets 81 per cent of its energy from fossil fuels and to cut emissions of carbon dioxide to just 14 gigatons per year, here is what the International Energy Agency says will have to be built every year between now and 2050: 35 coal-fired and 20 gas-fired power plants with carbon capture and storage; 30 nuclear power plants; 12,000 onshore wind turbines paired with 3,600 offshore ones; 45 geothermal power plants; 325 million square metres-worth of photovoltaics; and 55 solar-thermal power plants. That doesn’t even include the need to build electric cars and hydrogen fuel cell vehicles in order to shift transportation away from burning gasoline.

In addition, if the world’s economies hope to wean themselves from fossil fuels, they will have to significantly improve energy efficiency and begin to harness power from sources such as waste heat from factories.

One thing is certain: If the global economy does succeed in making the transition to renewable energy, the face of the planet will be significantly changed, with solar energy farms and wind turbines a common feature of many landscapes and seascapes.

Solar energy power plant, Mojave Desert USA. Photo: Warren Gretz/NREL
Concentrating solar power plant, Mojave Desert USA. Solar panels focus the sun's energy and super-heat oil to power steam turbine generators.
© Warren Gretz/NREL

“If 10 per cent of the U.S. electricity generated in 2009... were to be produced by large wind farms, their area would have to cover at least 22,500 square kilometres, roughly the size of New Hampshire,” writes environmental scientist Vaclav Smil of the University of Manitoba in his book, Energy at the Crossroads. “These new energy infrastructures would have to be spread over areas ten to a thousand times larger than today’s infrastructure of fossil fuel extraction, combustion and electricity generation…. This is not an impossible feat, but one posing many regulatory, technical and logistic challenges.”

“Can we do this or not?” Chevron's Rogers asks. “Even at the best time we ever had we only did 20 to 25 nuclear power plants in a year... We need 325 million square metres [of photovoltaics] annually. We’ve done maybe 10 percent of that in our best year, which was last year.”

But there is reason for guarded optimism. Even in the throes of the Great Recession, renewables accounted for more than 50 percent of newly installed generating capacity in the U.S. and the European Union, while China added 37 gigawatts of mostly wind and hydropower in 2009, according to the United Nations Environment Programme.

“It’s not going to be easy to make an energy plan that adds up; but it is possible,” says physicist David MacKay of the University of Cambridge, an expert on scaling up renewable energy. “We need to make some choices and get building.”

 

David Biello has been covering energy and the environment for nearly a decade, the last four years as an associate editor at Scientific American.

This article first appeared on the Yale e360 website. For an additional report on the US situation and readers' comments, go here .