100% renewable energy supply in USA feasible in 2050

24-08-2015

Interview with professor Mark Jacobson, Stanford University

In 2030, the United States could be 80% and in 2050 100% reliant on renewable energy. This is what professor Mark Jacobson, Director of the Atmosphere and Energy Program at Stanford University, and his colleagues, are writing in their latest study as part of the Solutions Project, for each of the 50 American states. In their scenarios, energy supply is completely based on wind, solar, geothermal and hydroelectric power, and to a lesser extent on tidal and wave energy. “Technically and economically, our scenario is feasible because the existing technologies can be implemented on a large scale”, says Jacobson. 

In each individual state, Jacobson and his colleagues first looked at how the energy demand would change in 2050 under business-as-usual conditions. They explored the energy consumption in four sectors: residential, commercial, industrial and transport. For each sector, they analyzed the energy sources currently being used: coal, oil, gas, nuclear, renewable. They then calculated the fuel demand if fuel consumption could be completely replaced by electricity. “We assume that all vehicles are electric and houses and industry completely switch to electric heating and cooling systems. In 2050, consumption could fall by 39 percent.”

Smart networks

To improve the processing of weather-dependent renewable energy in the grid, the research team is aiming for smart networks, which are properly planned and managed. Strong drops in solar and wind energy supply should, for example, be compensated by hydrogen-generated power or power from other renewable sources such as hydroelectricity. Batteries and biomass are not required (except for electric cars). Frequency regulation of the grid occurs via e.g. hydroelectricity, stored thermal solar power installations, pump storage plants and through de-energising excess renewable energy.

“The final costs spread out over a longer period of time would be approximately the same”

The researchers did not include biofuels in their plans. “The combustion of these fuels causes air pollution, the same as with fossil fuels. The carbon emissions throughout the life cycle is very uncertain, but at any rate higher than that of renewable technologies. Various biofuels use much more water and land than technologies based on sun, wind and water, and are ultimately less efficient. Photosynthesis, for example, has an efficiency of 1 percent, while solar panels have an efficiency of 20 percent.”

With these plans, no more than 0.5 percent of the land would be used for solar panels or wind turbines in each state. “The investment costs associated with this conversion are high, but wind and sunlight are free”, says Jacobson. “The final costs spread out over a longer period of time would be approximately the same as for the infrastructure, maintenance and production of fossil fuel. When you take the cost of environmental health problems and climate change into account - in addition to rising prices for fossil fuel - wind, water and sun cost around half of conventional systems.”

Figure: the necessary land area for power generation
Figure: the necessary land area for power generation

How to mobilize the population?

According to Jacobson, the biggest challenge is mobilizing the population. “This study is a means to inform the public about the possibilities. Many people don't know what the benefits are. Or they are afraid of job losses or high energy prices, while a large-scale transition such as this one actually creates jobs, stabilizes fuel prices and reduces environmental problems.” Jacobson sees that a number of companies and politicians as well are already convinced. “The state of Washington, for example, would be able to implement the switch to 100 percent renewable fairly quickly, because more than 70 percent of the current electricity consumption comes from existing hydroelectricity plants. Iowa and South Dakota already get almost 30 percent of their electricity from wind power. California has now adopted suggestions from The Solutions Project and wants to generate around 60% of all electricity from renewable sources by 2030.” Whether politicians at federal level can be convinced of the large-scale sustainable initiative? “Maybe presidential candidate Hillary Clinton will be enthusiastic about the plans”, says Jacobson.