A group of researchers at Stanford University and the University of California, Berkeley, led by Stanford’s Mark Jacobson and Mark Delucchi, says that the United States can get 100 percent of its energy from renewable sources, using existing technologies, by 2050. And they lay out a state-by-state plan for doing so. Jacobson and Delucchi had previously calculated that the world could theoretically go 100-percent renewable by 2030; in this more practical plan, they focus on the United States and look forward to 2050.
They conclude that, in aggregate, the the United States’ energy mix could be: 30.9 percent onshore wind, 19.1 percent offshore wind, 30.7 percent utility-scale photovoltaics, 7.2 percent rooftop photovoltaics, 7.3 percent concentrated solar power with storage, 1.25 percent geothermal power, 0.37 percent wave power, 0.14 percent tidal power, and 3.01 percent hydroelectric power.
Every state, of course, will have a different mix. The report concludes that California can meet 54.5 percent of its energy needs with some type of solar power, with wind power accounting for 35 percent. Five percent will come from geothermal, with hydroelectric power, wave power, and tidal turbines making up smaller percentages of the mix. North Dakota, the study says, can look towards meeting its energy demands with 42 percent solar power and 55 percent wind power. And Maine will be able to draw 70 percent of its energy from the wind.
Becoming a renewables-only country will require a number of steps besides building new large scale solar plants, installing rooftop solar, creating wind farms, and rolling out wave-power generating systems, the report indicates. For one, ground transportation will have to be entirely electrified. To do this, the researchers envision: battery-electric vehicles with fast charging or battery swapping dominating long-distance, light-duty transportation; battery-electric/hydrogen fuel cell hybrids dominating heavy-duty transportation and long-distance shipping; and electrolytic cryogenic hydrogen fuel used to power aircraft flight, with batteries providing energy for idling, taxiing, and internal electrical systems.
But change, the researchers indicated, will have to go beyond the way power is generated and used. The report contains a long list of other things that will need to be done—new building codes, improved data center design, surcharges on utility bills to fund the transition, easing the permitting process for electric car charging stations, improving bike routes, and much more.
Jacobson and his colleagues insist that this is all quite feasible—and that the economics make sense. “When you account for health and climate costs—as well as the rising price of fossil fuels—wind, water, and solar are half the cost of conventional systems,” Jacobson said in a prepared statement. “A conversion of this scale would also create jobs, stabilize fuel prices, reduce pollution-related health problems, and eliminate emissions from the United States. There is very little downside to a conversion.”
Tekla S. Perry is a senior editor at IEEE Spectrum. Based in Palo Alto, Calif., she's been covering the people, companies, and technology that make Silicon Valley a special place for more than 30 years. An IEEE member, she holds a bachelor's degree in journalism from Michigan State University.