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Efficiency Improvements Are Key to Holding Down Energy Demand

When the U.S. Department of Energy decided to build a new Research Support Facility to house 1,300 employees at its National Renewable Energy Laboratory in Golden, Colo., it created the largest building in the country that generates as much energy as it consumes.


Above: The net-zero-energy Research Support Facility at the National Renewable Energy Laboratory in Golden, Colo. Below: Much of the building's south-facing wall uses passive heating technology developed at NREL. | Pat Corkery/NREL

By cutting energy consumption through use of high-efficiency computers and other equipment, and by producing 2.5 megawatts of energy on-site through rooftop solar cells, the designers came up with a "net zero" energy structure that is meant to influence the design of other buildings in the United States and elsewhere.

Dan Arvizu, the laboratory's director, cited the support facility — completed in 2011 — as an example of technology that can help meet the energy demands of the future without requiring increased energy supplies. He described it during a 17 Nov. panel discussion at AAAS.

Among the features: Each work station is designed to use just 70 watts of power compared to 300 to 500 watts per work station at a typical office building. Arvizu said the LED computer monitors in the building use just 15 watts of power and the "thin client" desktop computers — which depend on remote servers to handle their computational load — use about 14 watts of power.

"Building efficiency is one of the easiest things to do" to reduce energy use, Arvizu said, although building codes and resistance to change can stand in the way.

Still, improvement in energy efficiency in a variety of settings has been a key to holding down energy demand in the United States, Arvizu said, and points the way toward reducing energy demand globally as well. "If we hadn't had efficiency improvements in the U.S. over the last 20 years, we would have 50 percent higher demand than we have today," Arvizu said.

He spoke at a discussion on "Emerging Technology and Global Energy Demand," part of the "Science and Society: Global Challenges" series co-sponsored by AAAS, the American Chemical Society, and Georgetown University's Program on Science in the Public Interest. David Kestenbaum, reporter for NPR's Planet Money, was the moderator.

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Grant Karsner | AAAS/Earl Lane

Grant Karsner, vice president of products research and technology for ExxonMobil Research and Engineering, also noted the importance of energy efficiency for future energy demand. In its annual outlook report on energy, ExxonMobil projects that global demand for energy will be 35 percent higher in 2040 but would be more than double today's usage without gains in efficiency.

"We feel that energy efficiency will be enormous," Karsner said. As an example, he noted that there are 800 million automobiles in the world today and that number is expected to rise to 1.7 billion by 2040. Yet there is expected to be no net increase in the amount of energy used to power all those vehicles.

The average fuel economy of cars today is 24 miles per gallon, Karsner said. "We believe in 2040 the average around the world will be 46 miles per gallon," he said.  How will that be accomplished? Karsner cited efforts by manufacturers to design lighter, more aerodynamic cars using smaller, hotter, more fuel-efficient engine designs.

Use of lower-viscosity or "thinner" lubricants that don't compromise on protection against automotive engine-wear can bring up to a 2 percent increase* in efficiency, Karsner said, while also reducing the amount of carbon dioxide a car will emit over its lifetime by one ton. "It's not very expensive to just go down to lower viscosity [motor oils],” he said. “But the technical challenge is to make sure that lubricant still protects the moving engine parts.” ExxonMobil’s report, “The Outlook for Energy: A View to 2040,” also predicts that by 2040 about 35 percent of light-duty vehicles in the world will be hybrids (combining an internal combustion motor and an electric motor).

800 million

The number of automobiles on the road today

1.7 billion

The number of automobiles expected by 2040


The predicted net increase in energy used to power the additional vehicles

Grant Karsner, ExxonMobil Research and Engineering

The report also predicts that in 2040 about 60 percent of the world's overall energy demand will still be supplied by oil and natural gas, with natural gas surpassing coal as the second largest fuel source behind oil. Non-OECD nations such as China and India will lead the growth in energy demand. But use of renewable energy sources will continue to grow. These figures came from ExxonMobil’s 2014 version of the report. The 2015 version was released in Washington, D.C. on 9 December.

Karsner noted that China wants wind power to account for up to 10 percent of its electricity generation by the end of this decade. In its own projections, the U.S. Department of Energy says that 80 percent of U.S. electricity production could come from renewable sources such as wind and solar by 2050, Arvizu said. "There is no limit to the amount of renewables you can incorporate into your system," he said.

Bruce Logan, a professor of environmental engineering at Pennsylvania State University, said there are other energy answers on the horizon. He showed a small plastic cube with several sheets of carbon paper in it. When water and bacteria are added, he said, it becomes a battery. "There are organisms in nature that can make an electrical current directly," Logan said.

Microbial fuel cells, as they are called, use bacteria for direct conversion of organic matter to electricity. They also can help solve another pressing issue.  Two billion people in the world lack adequate sanitation. Wastewater treatment plants use lots of electricity (5% of the U.S. electric output, for example). The organisms in Logan's microbial fuel cell can feed on any biodegradable material, including wastewater. There is enough energy potential in wastewater to run a treatment plant, he said. "It could even be a net power plant," he said.

"We believe all sources of energy are part of the future," Karsner said. "There will be growth in all areas" including wind and other renewables, pyrolysis of biomass, and nuclear energy. "We don't think there is one universal answer." Oil will continue to be a factor in 2040 and beyond. In 1980, there were predictions that oil sources would be depleted in 50 years, Karsner said, while last year there was a prediction that supplies will not be depleted for 125 years.

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Sarah Ladislaw and Bruce Logan | AAAS/Earl Lane

Logan and Sarah Ladislaw, director of the Energy and National Security Program at the Center for Strategic and International Studies, both noted that political and social forces will come into play in any long-term energy scenario.

Policy makers, focused in the here-and-now, "don't necessarily have the staying power" to put regulatory changes into effect to encourage new technologies, Ladislaw said. A lot will depend on aligning market forces and policy decisions, she said. Even when a policy makes sense, such as phasing out incandescent light bulbs for more energy-efficient varieties, higher costs and consumer resistance can come into play.

Ladislaw noted the substantial improvement in energy efficiency in new buildings over the past decade. But retrofitting new technology into existing buildings remains a challenge, given the lengthy payback period. Getting policy and pricing signals right is not easy, she said.

"We continue to burn whatever is the cheapest."

Bruce Logan

Logan cited the hopes for instituting a hydrogen economy. In one scenario, he said, biomass could be used, through a variety of processes, to produce hydrogen fuel for light-duty vehicles. But adoption of hydrogen as an automotive fuel would require a perfect sequence of events, he said, including properly phased construction of fueling stations and a willingness of consumers to buy the vehicles. "It's not that you can't do it," Logan said. But sometimes it's not just a technical solution that is required, he said. "It's a political and societal solution that needs to be made." In the case of the hydrogen economy, he suggested, "the government would need to bankroll it for the next 20 years."

For energy innovations generally, Logan said, "You have to hope for the tradeoff of economics and benefits. Right now, the cost is the one that we value the most. We continue to burn whatever is the cheapest." If that mindset changes, he said, "Perhaps you can take a different path."

Still, Karsner was optimistic about the future energy outlook. "There is an awful lot of progress that has occurred," he said, citing the dramatic increases in furnace boiler efficiencies since the 19th century. He is confident there will be similar advances in the decades ahead.

Arvizu noted that the United States is expected to spend $2 trillion over the next twenty years on new energy infrastructure. Globally, the figure is more like $20 trillion. "We are going to spend money on infrastructure," he said. "The question is what we spend it on." It need not be in the form of large, centralized power stations. Distributed power, in the form of solar panels on rooftops, already is becoming a major player in the U.S., he said, with 47 gigawatts of power generated through such systems.

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David Kestenbaum (left) and Dan Arvizu | AAAS/Earl Lane

Ladislaw said that while it is difficult to mandate technical change, putting incentives in place to drive change is a laudable goal. "You have to keep trying." Government and industry can work together to encourage market innovations and fund innovative research. Karsner said ExxonMobil spends about $1 billion a year on research and development. The company depends on the help of university researchers to bring expertise and new approaches to the table. "Universities open our aperture," he said.

In turn, universities have been changing their policies to make cooperative research projects more attractive to industry, Logan said. For a long time, Penn State insisted on retaining patent rights on any advances from company-funded research. "Companies weren't too happy about that," he said. Now, he said, the policy is: "You paid for it, you own it."

Arvizu, who chairs the National Science Board that sets policy for the National Science Foundation, said private sector funding has become a dominant factor in American R&D spending. The nation now spends about $400 billion a year on research, he said, with two-thirds of it coming from the private sector and one-third from government. That ratio used to be reversed.

The research ecosystem is changing, Arvizu said. "We need to be much more market relevant than in the past," he said. Science pursued for its own sake without regard to application used to have broad bipartisan support in Congress, he said. "Not anymore," he said. The bottom line now is: "What have you done for me lately?"

*This story was updated on 11 December to clarify that the goal for wind power in China is up to 10 percent of electricity generation, and that use of lower-viscosity lubricants in automotive engines can bring up to a 2 percent increase in efficiency, rather than 10 percent and 2 percent exactly.

[Credit for associated teaser image: Flickr/Jim Bumgardner]


Earl Lane

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