New research shows 139 countries could be entirely powered by wind, water, and the sun by 2050.
This would mean around 24 million long-term jobs, a decrease between four and seven million air pollution-related deaths, a stable energy price, and a likely saving of over US$20 trillion in health and climate costs.
Stanford's Mark Jacobson and a team of 26 researchers have created the most specific global vision for renewables in existence, detailing the infrastructure changes needed to make the transition.
For each of the 139 nations, they assess the raw renewable energy resources available to each country, the number of wind, water, and solar energy generators needed to be 80 per cent renewable by 2030 and 100 per cent by 2050, how much land and rooftop area these power sources would require (only around 1 per cent of total available, with most of this open space between wind turbines that can be used for multiple purposes), and how this approach would reduce energy demand and cost compared with a business-as-usual scenario.
"Both individuals and governments can lead this change. Policymakers don't usually want to commit to doing something unless there is some reasonable science that can show it is possible, and that is what we are trying to do," says Jacobson, who is the director of Stanford University's Atmosphere and Energy Program and the co-founder of the Solutions Project - a US non-profit educating the public and policymakers about a transition to 100 per cent clean, renewable energy.
The analyses specifically examined each country's electricity, transportation, heating/cooling, industrial, and agriculture/forestry/fishing sectors.
The 139 countries were chosen because they had publicly available data through the International Energy Agency, and collectively emit over 99 per cent of all carbon dioxide worldwide.
The study showed those countries with a greater share of land per population (the United States, China, the European Union) are projected to have the easiest time making the transition to 100 per cent wind, water, and solar. Another learning was that the most difficult places to transition may be highly populated, very small countries surrounded by lots of ocean, such as Singapore, which may require an investment in offshore solar to convert fully.
The study also showed that by eliminating oil, gas, and uranium use, the energy associated with mining, transporting and refining these fuels is also eliminated, reducing international power demand by around 13 per cent. Because electricity is more efficient than burning fossil fuels, demand should go down another 23 per cent.
The changes in infrastructure would also mean that countries wouldn't need to depend on one another for fossil fuels, reducing the frequency of international conflict over energy. Finally, communities currently living in energy deserts would have access to abundant clean, renewable power.
"Aside from eliminating emissions and avoiding 1.5°C global warming and beginning the process of letting carbon dioxide drain from the Earth's atmosphere, transitioning eliminates 4-7 million air pollution deaths each year and creates over 24 million long-term, full-time jobs by these plans," Jacobson says.
The 100 per cent clean, renewable energy goal has been criticized by some for focusing only on wind, water, and solar energy and excluding nuclear power, "clean coal," and biofuels. However, the researchers intentionally exclude nuclear power because of its 10-19 years between planning and operation, its high cost, and the acknowledged meltdown, weapons proliferation, and waste risks.
"Clean coal" and biofuels are neglected because they both cause heavy air pollution, which Jacobson and coworkers are trying to eliminate, and emit over 50 times more carbon per unit of energy than wind, water, or solar power.
The 100 per cent wind, water, solar studies have also been questioned for depending on some technologies such as underground heat storage in rocks, which exists only in a few places, and the proposed use of electric and hydrogen fuel cell aircraft, which exist only in small planes at this time.
Jacobson says that underground heat storage is not required, but certainly a viable option since it is similar to district heating - which provides 60 per cent of Denmark's heat. He also says that space shuttles and rockets have been propelled with hydrogen, and aircraft companies are now investing in electric airplanes.
Wind, water, and solar can also face daily and seasonal fluctuation, making it possible that they could miss large demands for energy, but the new study refers to a new paper that suggests these stability concerns can be addressed in several ways.
These analyses have also been criticized for the massive investment it would take to move a country to the desired goal. Jacobson says that the overall cost to society (the energy, health, and climate cost) of the proposed system is one-fourth of that of the current fossil fuel system. In terms of upfront costs, most of these would be needed in any case to replace existing energy, and the rest is an investment that far more than pays itself off over time by nearly eliminating health and climate costs.
"It appears we can achieve the enormous social benefits of a zero-emission energy system at essentially no extra cost," says Mark Delucchi, a research scientist at the Institute of Transportation Studies, University of California, Berkeley.