Can the world run on 100% renewable energy? The short answer is it needs to. With our rate of burning 35 billion barrels of oil per year, scientists estimate that we have consumed at least 40% of our oil reserves. This leaves us with 50 more years of oil and gas and a century for coal. For these reasons, nations are racing to develop and enhance new technologies for harnessing power from wind, solar, geothermal, and hydropower.
Currently only 13% of the world energy is sourced from renewables. With 173 terawatts of energy via sunlight reaching the earth continuously (approximately 10,000 times the energy we consume), solar panels covering 10% of the world deserts should be enough to generate all of that. However, the main drivers preventing us from building such large-scale energy projects are lack of accessibility, high manufacturing and installation cost, and low efficiency. Not every country or city has access to a large desert like the Nevada desert in the US or Sahara desert in Africa which means that energy must be transported over a long distance. This is not cost effective nor efficient due to energy dissipation from current power line technology.
Transportation is the second major use of fossil fuels. Currently battery powered electric cars use lithium ion technology which is a great alternative to fossil fuels. However, it provides 20 times less energy per kilogram than oil, making it more economical to use fossil fuels.
One should not worry, though. With major nations around the world investing in renewables and creative minds delivering next generation technologies, we will one day be able to achieve the efficiency and sustainability to source the majority of our energy from renewables.