On the south wall of the Sulzberger parlor in Barnard Hall hangs an elegant portrait of the dignified and unflappable Virginia Gildersleeve, first dean of the College (1911–1947). Beneath that oil painting, one late fall evening, Sally Benson ’77, director of the Precourt Institute for Energy, a research and education hub at Stanford University, delivered the annual Rosalyn Silver ’27 Science Lecture. The title: “An Energy Plan for the 21st Century.”
Benson, who came to Barnard unsure whether she wanted to be a ballerina or a physicist, knew by her junior year, when she took a geology course, that she was “interested in the earth.” She followed this interest to California, where a summer job at the Department of Energy’s Lawrence Berkeley National Laboratory set her on a path to becoming an energy researcher and environmental problem solver.
Beside her in the parlor, an oversize screen flashed graphs of lines and numbers nearly as complex as the New York City subway map. The scientist explained ways of mitigating the environmental effects of electricity generation by using the carbon-capturing method, which involves catching and storing CO2 so it cannot enter the atmosphere. She discussed the use of photovoltaics, which involves creating electricity from solar energy. Gildersleeve, whose tenure witnessed the arrival of subways, telephones, radio, typewriters, and the bare beginnings of television, appeared, from some angles, astonished.
Benson expressed her own astonishment at the advances that have been made in the last decade. On a subject that worries scientists and the public alike—devastating climate change as the result of supplying humans’ energy needs—she brought good news: “Change is here. We’re making fantastic progress.
“I never would have predicted the remarkable game changers we have seen,” she continued. The “enormous progress” has come from increasing the use of technology we already have, lowering the cost of that technology, and creating new ways to generate energy.
We already have wind power and its use is growing at a phenomenal rate. “Iowa now gets 40 percent of its energy from wind power,” she said. There is also solar power, the cost of which is plummeting fast. “In the 1970s,” she explained, “solar cells cost several hundred dollars per watt. A decade ago, it was six dollars a watt; now it’s 60 cents per watt.” Today’s solar cost is twice that of our current electrical system, but in sunny Hawaii and California, it can actually be cheaper than other, nonrenewable sources.
Benson also sees the reserves of natural gas as more good news. A decade ago, “The conventional wisdom was that the U.S. was running out of natural gas.” This proved untrue: “We have an abundant supply. We’ve seen a 50-percent rise in the use of natural gas. A positive view of resources for the energy future, then, rests on synergy: natural gas, wind, solar, and nuclear power.”
Those nay-saying experts also predicted perilously higher carbon dioxide emissions by now, but here, too, the picture, Benson insisted, is not so dire: “They are actually going down,” she said. Still, the bad news is very bad: 80 percent of the world’s energy still comes from fossil fuels—and the consequent carbon dioxide in the atmosphere is causing sea-level rise, ocean acidification, and climate change. The world is “running out of atmosphere and we don’t have much time. By 2100 we will need twice as much energy as we do today.”
What is to be done? Benson’s plan contains an array of global-scale efforts that harness existing technology and develop new solutions. The keys are energy intensity and carbon intensity, one needing to improve, the other to diminish. These are “the two knobs to turn, like diet and exercise. You have more chance of success if you do both.”
To increase energy intensity and, critically, keep costs reasonable, expanding battery life is paramount. This is where the company Tesla came in to the talk. The pioneering maker of electric cars—a spiffy red 4-door flashed on the screen and the audience sighed—is already selling a “power wall” unit to convert solar energy to electricity.
Benson also described her own expertise in “carbon capture,” which involves “scrubbing [carbon] out and sequestering it,” although the “how” of the process is still evolving. She is a passionate proponent of natural gas, which produces half the carbon dioxide emissions that coal does. “We have to substitute natural gas for fossil fuels,” she insists, not only because of the lower emissions, but also because “we need something easy to ramp up and down—natural gas is steady.” The resource is plentiful, but its method of extraction from the ground, or fracking, has proven, to some scientists and activists, dangerous. On this point, Benson said that the methane leaking into the atmosphere caused by fracking is “something we have to solve.” And “we” is not only everyone already working on the problem, but, she said, to an audience largely made up of Barnard students, “The solution must come in your lifetime.” Her generation learned about recycling in school and went home to teach their parents about it. Now, “it is in the hands of your generation.” She added, “We have 50 years.” •