Skip to contents
Renewable Energy

An Entirely Solar-Powered World Might Actually Be Possible


How do you solve the energy puzzle? In the greater discussion of climate change and the importance of society ending our centuries-long tradition of using oil and coal as our main sources of energy, the question for many then becomes this– what are we replacing it with? The oft-parroted solution is generally something along the lines of “oh, we will eventually figure it out” in reference to renewables. After all, humanity has been pretty effective in finding solutions to existential crises over history. When the polio epidemic was sending children to iron lungs and paralyzed an American president, top minds came together to develop a life-saving vaccine. When the Axis Powers and the rise of fascism nearly brought the world to its knees, the democratic Western powers formed an unlikely alliance with a diametrically opposed Stalin-led Russia in order to stop it. Time and time again, history has proved that the recipe to thwarting once-in-a-generation threats is simply throwing enough resources into a solution.

Climate change, while terrifyingly different from war or disease in origin and scope, still abides by that same playbook. Some may make the argument that renewable sources are inadequate in their ability to consistently keep up with global energy consumption and that therefore a certain level of traditionally produced energy will continue to be a necessity. This viewpoint does not look further than the current state of renewable infrastructure worldwide. New information points to the idea that this argument will soon be made obsolete. 

Image courtesy of Roy Buri

Published in October of this year, a study from Ireland’s University College Cork found that the world’s potential for solar energy production alone is even more underutilized than previously expected. At the university, researchers developed a machine-learning algorithm that was used to analyze a total of 130 million square kilometers across the globe. That number was then narrowed down to 200,000 square kilometers of rooftop over six continents (sorry Antarctica) that were determined to be capable of supporting some type of solar panel infrastructure, adjusting for factors such as total area, local population density, and classification of rooftops as commercial or residential spaces. 

If there was any debate over whether solar power was a viable full-scale alternative for the future or simply a pipe dream for environmentalists, the findings of this study lend a lot more credence to the former.

Should a worldwide effort be made to fit solar panels to these rooftops, it is estimated that the total output of infrastructure of that level would be in the realm of 27 petawatt-hours, or 27 quadrillion watt-hours of energy every year. To put this into perspective, that number is greater than the overall sum of energy used worldwide in 2018 – and it’s all coming from the sun. 

Image courtesy of Voltaro

If achievable, these numbers would be monumental. As of 2019, between one and two percent of the world’s energy was derived from solar, so bringing that number anywhere near 90 to 100 percent would put the world in an almost inconceivable strong long-term position for combating the extinction-level threat that is climate change. We would theoretically be able to reduce global emissions to levels far below even the most ambitious year-2050 targets and, more importantly, be able to plan for a healthy society centuries down the road instead of decades. 

This kind of effort would be expensive. Costs would vary by region, with some of the cheapest countries like China and India sitting at an estimated average installation cost of around $60 to 70 per megawatt-hour. The vast majority of rooftop potential exists within North America, Europe, and Asia, with the latter making up 47 percent of that total. All in all, it would likely cost the world somewhere between $2 to 5 trillion, with extreme estimates between $1 and 7.5 trillion. Considering the fact that the US alone has spent about that much on combating the pandemic, the number looks more than reasonable.