3 AIR: Reap the Wild Wind

THE CHALLENGE  Anyone who made a cross-country trip in the last few years will have seen the transformation that turned the United States into the world’s leading producer of wind energy. The wind farms that now punctuate the landscape from California to New York produce a total of almost 100 terawatt-hours of electricity a year, almost 2.5 percent of total demand. But that is still small potatoes compared with the 45 percent generated by coal-fired plants. There are a host of scientific issues to overcome before wind can seriously challenge fossil fuels, but one of them is surprisingly basic: We still do not completely understand the way winds blow. The wind behaves differently 200 to 400 feet up, where the turbines actually operate, than it does near the ground. “We have thousands of monitoring stations around the country measuring the wind up to about 30 feet,” says William Mahoney III, a deputy director at the National Center for Atmospheric Research in Boulder, Colorado. “But very few above that.”

THE NEW ENERGY ECONOMY  Because of the lack of data, energy projections at wind farm sites can be highly inaccurate, with errors of up to 20 percent in farms that are built over uneven terrain. A small change in the wind has big implications: 
A 10-mile-an-hour wind can generate 65 kilowatts, but at 15 miles an hour, the same turbine can produce 300 kilowatts. Complex airflows over hills and mountains create wind shear and turbulence that produce stress on turbines’ blades, gearboxes, and bearings. Since turbines are designed without a complete understanding of such wind flows, they are failing at higher than expected rates. Failure to anticipate sudden gusts is especially problematic, because they can both damage the turbines and lead to sudden transmission line overloads. The situation is similar to the early days of aviation, when aircraft designers were working by trial and error because the atmosphere was so poorly understood.

Being able to predict average wind speed within just a fraction of a mile an hour would make a huge difference. The way to do that, Mahoney says, is to gather the missing data. Government, academia, and industry need to invest in new research on wind flow that will allow us to truly wrap our heads around what’s going on up there—and to reap the full benefits of wind power.

4 EFFICIENCY: Exploit human Behavior

THE CHALLENGE  The greatest clean energy sources and efficient technologies are pointless if nobody wants to use them. Sometimes the resistance reflects a problem of engineering (for instance, the short range, high cost, and long charging time of electric cars). Often, though, the problem is one of perception. “Our default is the status quo, and we have a myopic focus on the here and now,” says Elke Weber, a psychological economist at Columbia University who studies why 
people engage in risky environmental behavior. She argues that understanding consumer behavior needs to be at the heart of a meaningful energy policy.

THE NEW ENERGY ECONOMY  Some of the most effective strategies to help consumers overcome aversion to change are very simple. Weber finds that merely offering the energy-efficient option as the default choice can greatly increase its acceptance. She examined the familiar lightbulb decision: Should I buy a compact fluorescent bulb (CFL) or go with the more familiar incandescent bulb that is cheaper but eats up more electricity? (An average incandescent bulb is $0.50 and will cost you $49 per 10,000 hours of use. Compact fluorescents may run you $3, but rack up an electricity cost of only $11 per 10,000 hours of use.)

In a survey, when Weber made incandescent bulbs the default option (in a newly renovated home, for instance), 44 percent of consumers said they would stay with the choice. But when CFLs were presented as the default option, 80 percent went with them instead. Consumers have registered some complaints about CFLs, but it seems that one of the most intense ones is the hassle of making a change.

New York University economist Hunt Allcott has demonstrated that competition can also spur people to make more efficient choices. He studied Opower, a company headquartered in Arlington, Virginia, that sends utility subscribers an energy “report card” comparing their energy usage with that of their neighbors.

Opower now includes these kinds of comparisons in the utility bills of 15 million households across the United States. Allcott’s analysis shows that customers who receive the notices become more conscious of energy use and consume an average of 2 percent less power than those who do not get the comparisons in the mail. There is no government mandate, no utility incentive, just a better kind of communication.

The letters are being used by some utilities to target heavy electricity users who may not be aware that they are wasting energy, and their own money.

The Experts



Hunt Allcott

Economist, New York University

David Blackwell

Geophysicist, Southern 
Methodist University

James Faulds

Director, Nevada Bureau 
of Mines and Geology

Karl Gawell

Executive director, Geothermal 
Energy Association


Rob Gramlich

Senior vice president, American 
Wind Energy Association

Richard Luthy

Director, Engineering Research Center for Reinventing the Nation’s Urban Water Infrastructure at Stanford University

William Mahoney III

Deputy director, Research Applications Laboratory, National Center 
for Atmospheric Research

Patricia Mulroy

General manager, Las Vegas 
Valley Water District

Thomas Peterson

Assistant director, NSF’s 
Directorate of Engineering

Saifur Rahman

Director, Advanced Research 
Institute at Virginia Tech

Elke Weber

Codirector, Center for Decision Sciences, Columbia University