About 286,000 sq km of the world is covered with rooftops. (Image source: Adobe Stock)
According to new study from the University of Sussex, installing solar panels on rooftops may reduce global temperatures by 0.13 degrees.
The study also suggested that this could end up supplying the majority of the world's electricity.
About 286,000 sq km of the world—an area comparable to that of Italy or New Zealand—is covered with rooftops.
According to the study, photovoltaic solar (rooftop PV) could provide 19,500 TWh of power annually if every appropriate roof was employed. If combined with load shifting and battery-electric storage, this would nearly entirely replace fossil fuel-based electricity and cover 65% of current world demand.
The impact of widespread solar deployment by 2050 was simulated by the researchers using sophisticated climate models. 0.13 degrees Celsius is a substantial portion of global warming. According to a 2023 Nature study, an additional 140 million people will be exposed to harmful heat for every 0.1 degree of warming beyond current levels.
The researchers urge politicians to give this technology top priority, arguing that solar electricity is more cost-effective for taxpayers than nuclear.
A shift toward PV
University of Sussex climate and policy researcher Prof Felix Creutzig, said, “Solar is now outcompeting nuclear power in cost, deployment speed and environmental risks. Given its immediate carbon reduction benefits governments should consider shifting incentives toward rooftop PV instead of nuclear. This goes for cooler countries like the UK as well as those with more obvious solar potential.
“Beyond carbon savings, reducing fossil fuel dependence also means cleaner air and better energy security. With so much untapped potential in solar it’s hard to see how governments can justify investing in nuclear, or as yet unproven carbon capture projects.”
Over the past ten years, the cost of solar power has drastically decreased. According to IRENA data, new nuclear projects like Small Modular Reactors are expected to cost between £100 and £150 per MWh, whereas the levelized cost of power for solar is now between GBP£30 and £50 per MWh.
In order to place solar panels where they can be most effectively utilised, the paper promotes international cooperation. Only 1% of rooftop PV installations are in Africa, despite the region having the greatest solar energy resources in the world. This underscores the need for investment. East Asia has the most potential for rooftop PV to mitigate climate change due to its high carbon intensity and vast building stocks.
Meanwhile, North America and Europe, despite lower solar intensity, have a high combined installation potential of over 4,300 GW or 25% of global capacity based on their high building stock.
According to the International Energy Agency, the UAE's low-emissions power generation share increased from 3% in 2019 to 35% last year due to the growth of nuclear and solar power. While the UAE is continuing to grow its nuclear capacity, its solar PV capacity continues to grow as well.
