Civil and environmental engineering professor Mark Z. Jacobson set out a grim primer on climate and energy problems in a talk at the Stanford Blood Center's Café Scientifique in March. His intent was not merely to alarm the packed room with data—all scientifically valid—about rising temperatures, rising tides and fossil fuel resources being fully depleted in 100 to 150 years. He wanted to galvanize action.
There is a solution to our environmental nightmare, Jacobson promised, and it's within our reach—if only policy makers would act on his plan. That blueprint is the result of a massive 2009 project he conducted with Mark DeLucchi, a research scientist at UC-Davis, to evaluate renewable energy sources and technologies in terms of cost, feasibility and environmental impact.
The answer comes down to wind, water and sun. By mobilizing technologies based on these abundant natural resources, we can provide 100 percent of the world's energy requirements, eliminating all need for fossil fuels within 20 to 40 years, asserted Jacobson, '88, MS '88, MS '91, PhD '94, who directs Engineering's atmosphere/energy program. "That means electricity, transportation, heating, cooling and industrial processes—everything we use energy for."
Converting to wind, hydroelectric and solar power will in itself reduce global power demand by 32 percent. It will forestall global warming, providing stable, low-cost and plentiful supplies of energy that comfortably exceed the world's needs and require minimal land areas to establish. Moreover, it will prevent the millions of health challenges and deaths that result from air pollution each year.
Among the technologies Jacobson and DeLucchi's research shows to be the best are wind, tidal and wave turbines; photovoltaic panels; battery-electric and hydrogen fuel cell vehicles; hydroelectricity; and methods to capture geothermal energy, heat naturally produced and stored in the earth. "All of them work or are close to working today on a large scale; they're not distant possibilities that may exist 20 or 30 years from now," Jacobson said. "They also produce hardly any greenhouse gases and air pollutants at any time in their life cycle—from construction and operation to decommissioning.
"It's not rocket science, it's just a matter of optimization," he stressed, noting that his plan recommends combining and coordinating such technologies across a global grid. This would comfortably make up for shortfalls in any location where the sun might be clouded over or the wind becalmed.
For Jacobson, no-no's included nuclear technologies as well as some recent favorites of the ecologically minded, such as natural gas, ethanol made from corn or sugarcane, and the capture of carbon from coal. "Nuclear power results in up to 25 times more carbon emissions than wind energy, when you consider reactor construction, uranium refining and transport, and the 11 to 19 years between planning and operation of a nuclear reactor," he explained. "Carbon capture technology can reduce carbon dioxide emissions from coal-fired power plants but will increase air pollutants—and itself requires more coal to be burned to power its own capture and storage steps. As to ethanol, even the most ecologically acceptable sources of it create air pollution that will cause the same mortality level as when gasoline is burned."
The key to Jacobson's solution is to not wait for more research and development, but use existing technologies and create national and international "supergrids" to assure transmission of energy from one place to another. "And that's a zoning and political problem, not a tech problem," he said.
Jacobson and DeLucchi's analysis strongly suggests that some wind, water and solar technologies cost more for a while, but eventually they will be as inexpensive as traditional sources. "Some combination of subsidies and carbon taxes would thus be needed for a time," Jacobson said. He recommends a tariff program to cover the difference between power generation costs and wholesale electricity prices to help scale up new technologies. Auctions in which the right to sell power to the grid goes to the lowest bidders would provide incentives for renewable energy developers to lower costs.
"With sensible policies, nations could generate 25 percent of their new energy supply with renewable sources in 10 to 15 years, and almost 100 percent of new supply in 20 to 30 years," said Jacobson, who has been giving talks to scientists and policy makers as well as guiding research. "With extremely aggressive policies, all existing fossil fuel capacity could theoretically be retired and replaced in the same period, but it's more likely that full replacement may take 40 to 50 years." Former U.S. Rep. Jay Inslee, Democratic candidate for governor of Washington, has called the plan's vision "one that the United States really needs."
"Clear leadership is needed," said Jacobson, "or else nations will keep trying technologies promoted by industries rather than vetted by scientists. It's going to take ongoing education."
Marguerite Rigoglioso is a Bay Area freelance writer.
