
New research highlights the vast potential of rooftop solar, urging policymakers to prioritise PV over nuclear for cleaner, cost-effective energy. (Image source: Adobe Stock)
Covering rooftops with solar panels worldwide could supply most of the planet’s electricity needs while also reducing global temperatures by 0.13 degrees Celsius, according to new research from the University of Sussex
With rooftops spanning approximately 286,000 km²—comparable in size to Italy or New Zealand—the study suggests that if all viable surfaces were equipped with photovoltaic solar panels, they could produce 19,500 TWh of electricity annually. This output would account for 65% of current global electricity consumption and, when combined with load shifting and battery storage, could largely replace fossil fuel-based power generation.
Using advanced climate models, researchers projected the impact of large-scale solar adoption by 2050. A temperature reduction of 0.13 degrees Celsius is significant, considering a 2023 Nature study indicated that each 0.1-degree rise in global temperatures exposes an additional 140 million people to extreme heat.
Is rooftop solar the better investment?
The study urges policymakers to prioritise rooftop solar technology, emphasising that it provides taxpayers with better value than nuclear power. Felix Creutzig, a climate and policy expert at the University of Sussex, stated, “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.”
The cost of solar power has plummeted over the past decade. According to the International Renewable Energy Agency, the levelised cost of electricity (LCOE) for solar now ranges between GBP £30 and £50 per MWh (approx. USD$38.77 to US$64.62 per MWh, whereas newer nuclear projects—such as Small Modular Reactors—are estimated to cost between £100 and £150 per MWh (approx. USD$129.22 to US$193.84 per MWh).
“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,” remarked Creutzig
The research underscores the importance of global collaboration in deploying solar panels where they can be most effective. Despite Africa having the highest solar energy potential, the continent accounts for just 1% of global rooftop PV installations, highlighting the need for increased investment. East Asia, with its dense urban areas and high carbon intensity, presents the greatest potential for rooftop solar as a climate mitigation strategy. Meanwhile, North America and Europe, though less sun-rich, possess extensive building infrastructure, offering a combined rooftop PV installation potential of over 4,300 GW—equivalent to 25% of the global capacity.