Three of the greatest problems facing humanity today are air pollution mortality, global warming, and energy insecurity.
Air pollution kills 4-7 million people prematurely each year worldwide and 65,000 per year in the United States and 12,500 per year in California, costing the world, the U.S. and California about $23 trillion per year, $600 billion, and $100 billion per year, respectively.
Global warming and its increases in sea-level, coastal flooding, air pollution; heat stress, heat stroke, and disease; agricultural losses; severe storminess and drought; and ocean coral and fish losses costs the world trillions of dollars per year today and will cost $29 trillion per year by 2050.
Third, because fossil fuels are limited resources that are often mined far away and require continuous drilling, extracting them leads to international conflict and land/water despoilment, and their finite supply is increasingly causing national and international economic, social, and political instability.
At Stanford University and the University of California at Berkeley, we researchers, along with dozens of students and other researchers from around the world in the areas of engineering, transportation, renewable energy, atmospheric sciences, and economics, and in collaboration with The Solutions Project, have developed roadmaps to transition all energy in the 50 United States and 139 countries (representing more than 99% of all emissions) to 100% clean, renewable energy for all purposes.
The idea behind the roadmaps is simply to electrify everything and provide the electricity with clean, renewable energy, namely wind, water, and sunlight (WWS). By everything, we mean transportation, heating/cooling, and industry. In the end, we will use no natural gas, 2 coal with carbon capture, biofuels, or nuclear power. We will use no combustion and will virtually eliminate emissions of pollutant gases and particles.
We will need some low-cost storage to store electricity, heat, and cold for when the wind is not blowing and the sun is not shining. Fortunately, low-cost storage technologies already exist. For electricity, we have concentrated solar power with storage, pumped hydroelectric storage, and existing hydroelectric dams, which are like big batteries. Batteries themselves will also be used to store electricity, particularly in cars, although we may not need so many batteries to store electricity because other low-cost electricity storage exists plus electrifying all energy sectors makes it easier to match power demand with supply.
Further, we will store heat in water and underground rocks. We will store cold in water and ice. We will also use excess wind and solar to produce hydrogen, which is a form of storage. Hydrogen will then be used for long-distance trucks, ships, and planes.
Another way to ensure that electricity is available when people need it is to connect wind and solar long distance on the transmission grid. This allows wind or solar electricity to be brought to a city from far away when wind and solar resources are currently low.