APS News

Conferees Grapple with Climate Change, Sustainable Energy

By Michael Lucibella

Researchers and technical experts speaking at the second Physics of Sustainable Energy conference emphasized the urgent need to change how the planet generates and uses energy. The conference, sponsored by the APS Forum on Physics and Society (FPS) and held at the University of California, Berkeley, in early March, highlighted new research and technology aimed at better understanding and combating climate change.

Talks on the first day of  the two-day meeting included discussions on energy policy, the environmental effect of fossil fuels and ways to clean up transportation, while the second day was devoted to ways to make buildings more efficient and to sources of renewable energy.

Though much of the conference was devoted to looking for energy solutions, speakers at the beginning of the program offered a defense against critics of anthropogenic global climate change.

“Natural causes alone cannot –I repeat cannot–explain the…changes we’ve actually seen,” said Ben Santer, a climatologist at Lawrence Livermore National Lab. He pointed to his research showing that different layers of Earth’s atmosphere have been warming at different rates, rather than evenly, as they would if the sun were changing. “’The sun explains everything’ does not fit the available data,” Santer said.

The tone of many of the presentations indicated that there is no silver bullet or panacea to solve climate change and completely fulfill the looming energy needs of the planet. Speakers pointed to an inexorably warming planet with limited resources, a growing population and a global demographic shift towards urbanization and higher energy use per capita. These challenges are daunting and will take a concerted effort from wide swaths of society including researchers developing the latest green technologies, policy makers making tough decisions and a public willing to change its behavior.

Scientists estimate that the biggest single source of greenhouse gases is transport, especially cars. Sonya Yeh, a researcher at the University of California, Davis said that emerging alternative fuels for cars, including electric batteries, hydrogen fuel cells and biofuels each had their own advantages and disadvantages

“We don’t know what [fuel] will win out, but we’ll probably need them all,” Yeh said. She added also that in order for the switch to sustainable fuels to take root, the government would likely have to step in and help make the adjustment.

“Infrastructure is probably the number one challenge we’re facing when trying to get to a sustainable future.”

Tim Lipman, co-director of the University of California’s Transportation Sustainability Research Center, showed a brief history of fuel technologies and weighed in on their possible futures. Battery capacity has improved dramatically in the last 20 years, to the point where plug-in electric and hybrid cars are able to compete commercially. Hydrogen fuel cells have similarly made significant strides, but still generally have limited ranges and are not quite ready for the market.

“It’s a lot easier to concentrate emissions at power plants and clean them up than it is to clean up millions of tailpipes,” Lipman said. “Cars are only as clean as the electricity and hydrogen used to fuel them.”

Converting the United States to clean sources of electricity provides its own sets of problems. The Department of Energy recently deemed doubling the United States’ reliance on renewable energy, from 10 percent to 20 percent by 2035, as an “aggressive but achievable” goal. However, in order for clean sources of energy to become adopted more widely, the cost of renewable fuel sources like solar and wind would have to come down significantly to be competitive with fossil fuels like coal and oil. K. John Holmes from the National Academy of Sciences examined whether it was likely to see the costs of renewable energy come down in price.

“Renewable electricity is generally more costly (except for hydro, wind and traditional geothermal) to produce than fossil fuels… So we need those policy incentives to drive increases,” Holmes said. “Just having adequate technology capable of efficiency and reliably producing electricity is not sufficient to have non-hydro renewable energy make a significant contribution to the US energy market.”

Nuclear energy received a strong defense from Robert Budnitz of the Lawrence Berkeley National Lab. He pointed to the fact that nuclear power can deliver electricity at rates that can compete with fossil fuels without the greenhouse gas emissions. Historically nuclear power has had a mixed safety record and lax oversight culminating in the 1979 Three Mile Island accident. Budnitz said that since then the industry has doubled down and focused on safety and reliability. He pointed to a bevy of statistics showing that the number of “significant incidents” at each plant has fallen from an average of 4 per year in 1979 to .01 today.

“What all this is telling us is the systems are reliable and the people are reliable,” Budnitz said.

As important as the generation of power is its transfer to consumers. George Crabtree, from Argonne National Lab and co-chair of the APS study Integrating Renewable Electricity on the Grid, said that the United States has huge potential solar and wind resources, but they’re generally far from where people live. He highlighted also how the grid would need to be able to smooth out disruptions in supply of solar and wind energy on cloudy and calm days respectively.

“Renewables require a nationally coherent electricity grid, and that’s clearly something that we’re very far from at the moment,” Crabtree said. Crabtree co-authored a Back Page based on the APS study in the December, 2010 issue of APS News.

Other talks highlighted improvements in solar photovoltaics, systems to gauge the energy consumption of buildings, successes of policies in the state of California, as well as nationally, to improve energy efficiency and future energy consumption in the developing world.

Though the problems described sometimes seemed intractable, most speakers remained optimistic that new technology and governmental policies could dramatically change how the country conserves energy. During his talk, Arthur Rosenfeld, who recently retired from the California Energy Commission, described how refrigerators kept getting bigger and cheaper after federal regulation of their energy efficiency. He said that with the proper political backing, these kinds of energy savings could be spread to many products.  

“This is the second golden age of energy efficiency,” Rosenfeld said.

FPS had also helped to sponsor the first Physics of Sustainable Energy conference in 2008, often referred to as “The Woodstock of energy sustainability” by its participants. This year’s conference had talks on many of the same topics, but featured all-new speakers.

Organizer of the conference, David Hafemeister from the California Polytechnic State University, said that he was pleased with the turnout and he hoped that physicists and students attending the conference might consider focusing in renewable energy research.  

“Physics is the best discipline for understanding these things,” Hafemeister said.

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Editor: Alan Chodos