There are no technological or economic reasons why we cannot completely replace fossil fuels with renewable sources of energy. In addition to curbing climate change causing greenhouse gas emissions, renewable energy also improves human health. Minimizing climate impacts and reducing health costs would generate trillions of dollars of cumulative savings.
The idea that the world can be powered entirely by renewable energy is not new. In 2011, Stanford researcher Mark Z. Jacobson and UC-Davis researcher Mark A Delucci concluded that the world can be powered by clean and sustainable energy. The study they co-wrote authored found that using existing technology, the world can abandon fossil fuels and adopt renewable energy in as little as two decades. The researchers further stated that this can be done for the same price as conventional energy.
There are already commitments and functioning examples of 100 percent renewable energy use. In 2014 a number of leading companies pledged to get their power entirely from renewables. The EPA's Green Power List reviews the growing number of businesses, municipalities and universities that use only clean energy.
Hawaii has been reducing its dependence on fossil fuels to generate electricity, but the state still uses petroleum for 70 percent of its energy generation. A new bill will abandon oil altogether and require the state to get all of its energy from renewables (primarily wind, solar, geothermal and hydro) by 2040.
California is working towards the goal of getting one third of its electricity from renewable sources by 2020. New research suggests that California could produce enough solar energy to provide as much as five times the electricity it currently consumes. This is achievable by deploying solar in developed areas (roof tops or open spaces on the ground) close to where people live and consume power.
California is already getting more than 12 percent of its power from renewable sources and individual cities in California are going even further. San Jose, San Francisco and San Diego have all pledged to get off fossil fuels, starting in 2022, 2035 and 2020 respectively. The San Diego 100% Renewables report shows how San Diego can get all of its electricity from renewable energy.
As of 2014, Aspen Colorado was getting more than 86 percent of its energy from renewables (hydro and wind) and the city has vowed to go 100 percent renewable by the end of 2015. Early in 2015, Burlington, Vermont became the first US city to deliver on the promise to end fossil fuel use for electricity and meet all of their power demands with renewables (biomass, hydroelectric, solar and wind).
On March 18, 2015, Georgetown, Texas announced that it would soon be generating 100 percent of its electricity from renewable sources (solar and wind). What makes this noteworthy is the fact that Texas is the largest oil producing state in the US. The reason Georgetown is turning to renewables is because they are a cheaper source of electricity than fossil fuels.
A number of studies show that renewable energy can meet or exceed U.S. energy demands in a timely fashion. U.S. National Oceanic and Atmospheric Administration (NOAA) research indicates that renewable energy can replace fossil fuels within 20 years. Sandy MacDonald, director of the earth system research lab at NOAA said that wind and solar could supply 70 per cent of electricity demand in the lower 48 states, with fossil fuel and hydro/nuclear renewables each accounting for just 15 per cent by 2030.
The National Renewable Energy Laboratory's (NREL) Renewable Electricity Futures Study (RE Futures) found that using a diverse array of commercially available technologies, the US could easily supply 80 percent of its electricity needs with renewables by 2050. The Union of Concerned Scientists published a plan for renewable energy to provide 80 percent of our electricity by 2050.
A recent Stanford paper entitled “100 percent Wind, Water, Sunlight (WWS) All Sector Energy Plan for the 50 U.S. States,” suggests that the United States can get all of their power needs from renewables.
These U.S. examples alongside research from all around the world (Europe, Asia, Latin America, Canada, Australia, Africa and the Middle East) reveals that renewable energy has the potential to quickly and affordably replace fossil fuel as the world's primary source of energy.
As pointed out in a Bloomberg article, renewable energy has “passed a turning point” and we can now say with confidence that 100 percent is possible. The world is shifting away from fossil fuels and towards renewables.
"The shift occurred in 2013, when the world added 143 gigawatts of renewable electricity capacity, compared with 141 gigawatts in new plants that burn fossil fuels," the article stated. "The shift will continue to accelerate, and by 2030 more than four times as much renewable capacity will be added."
The fossil fuel lobby frequently point to the problem of intermittency of renewables (eg the sun is not always shining and the wind is not always blowing). However, as pointed out in a another Bloomberg article, the example of Germany proves the naysayers wrong.
Cheaper storage will further minimize the so called intermittency problem. “There’s a myth among opponents of renewable energy that you need 100 percent backup spinning all the time, and it’s utter nonsense,” said Michael Liebreich, founder of Bloomberg New Energy Finance.
The world will transition away from fossil fuels and towards renewable energy, the only question that remains to be answered is how long it will take.
The real issue is not about technological feasibility or even economics, it is about political will.