While policymakers in national governments are debating whether or how much to address global warming, over 70 cities and towns in the United States alone have committed to transitioning to 100% clean, renewable energy in one or more energy sectors. Each locality, though, needs a way to get there. In a new paper published this week in Sustainable Cities and Society, colleagues from Stanford University and U.C. Berkeley provide roadmaps for 53 towns and cities across North America to obtain 100% of their energy from wind, water, and solar power plus storage. The cities include large ones, such as New York City, Mexico City, Los Angeles, Toronto, Montreal, Chicago, San Francisco, Atlanta, Boston, Denver, and Phoenix as well as small ones, such as Abita Springs (Louisiana), Boone (North Carolina), Moab (Utah), Denton (Texas), and Standing Rock (North Dakota), among others.
The proposed transition timeline is an 80% conversion by 2030 and 100% by 2050.
If such a transition occurs, the towns and cities collectively are projected to gain 93,000 more permanent, full-time jobs than are lost, reduce each person’s energy cost by about $133 per year, and eliminate a total of about 7,000 air pollution deaths per year, according to the study.
The main idea behind the plans is to electrify or provide direct heat for all energy, then to produce the electricity and heat entirely with onshore and offshore wind, solar photovoltaics on rooftops and in power plants, concentrated solar plants, geothermal plants, existing hydroelectric plants, and small numbers of tidal and wave devices. Because the wind doesn’t always blow and the sun doesn’t always shine, storage will be needed as well. When excess wind or solar is available, it will be stored as electricity in batteries or pumped hydroelectric storage; as heat in water or underground rocks; as cold in water or ice; or in the form of hydrogen. Excess water will be stored in existing hydroelectric reservoirs, which are basically big batteries. When no direct wind, water, or sunlight is available, energy will be drawn from storage. Grid operators will also set prices to reduce electricity use during times of peak consumption, as is done now.
Each energy sector will be transitioned as follows: transportation, including cars, trucks, buses, construction machines, ships, trains, and aircraft, will run on batteries and/or hydrogen fuel cells, where the hydrogen is produced from electricity. Building air and water heat will be provided by electric heat pumps, as will refrigeration and air conditioning. Cooktops will be electric induction. Leaf blowers and lawn mowers will be electric. High-temperature industrial heat will come from electric arc furnaces, induction furnaces and dielectric heaters. In other words, all combustion-based energy-consuming devices and machines today will be transitioned. No natural gas, nuclear power, biofuels, or coal with carbon capture will be needed.
Such a transition is estimated, across the 53 towns and cities considered, to reduce end use power demand in 2050, compared with a “business-as-usual” case by 54-69%. This reduction is due to the higher work output per energy input of electricity over combustion; eliminating the energy used in mining, transporting, and refining fossil fuels; the efficiency of heat pumps over combustion heating; and end-use energy efficiency improvements beyond those in the business-as-usual case.
From the end use power requirements calculated for each town and city, a mix of wind-water-solar energy generators was proposed based on the availability of renewable resources within the state that the town or city resides in. Subsequently, the numbers of jobs created and lost to build the new infrastructure and eliminate the old infrastructure were calculated. Changes in energy costs, air pollution health costs, and climate costs were similarly determined.
The most important result is that all towns and cities examined can transition at low cost while, on aggregate, creating jobs, saving consumers money, and reducing climate impacts. The obstacles for such a transition are no longer technical or economic, but social and political. This result gives us hope for a brighter future for our planet.