Why solar power is the only viable power source in the long run

In recent years, solar energy has emerged as a powerful solution to our escalating energy needs and the ongoing climate crisis. With its cost efficiency and sustainability, solar power is no longer a distant dream, but a contemporary reality transforming energy generation.

Despite its rise, the discourse around solar power is often muddled by misinformation. Recently, U.S. Energy Secretary Chris Wright argued that solar energy could not sufficiently meet global energy needs. This claim has been widely challenged, indicating a significant misunderstanding of solar energy’s capabilities. In fact, when integrated with wind energy—which harnesses solar energy via different means—renewable sources can satisfy global demand without exacerbating climate change.

On September 2, Wright claimed on social media that engulfing the entire planet in solar panels would only yield 20% of the world’s energy needs. Such a simplification overlooks the critical equation of electricity and energy. As clarified by Gavin Schmidt from NASA’s Goddard Institute, the total energy capital used worldwide in 2024 was estimated at 186,000 terawatt-hours (TWh), while the Earth receives energy equating to 6000 times that figure annually.

Schmidt explained that with 60% of fossil fuel energy lost during conversion, the sun provides 18,000 times the energy currently utilized at present. Though existing solar technologies only capture about 20% of sunlight, a 2021 report from Carbon Tracker concluded that a mere 0.3% of the globe’s land area would suffice to fulfill today’s energy requirements through solar power alone—less than the spatial footprint of fossil fuel systems. This raises an optimistic viewpoint: solar and wind technologies could surpass our current energy consumption by upwards of 100 times.

Given that fossil fuels currently induce significant climate disruptions, it’s advantageous that there isn’t sufficient fossil fuel capacity to meet energy demands 100 times over. But how does it compare to nuclear fusion? Would fusion energy be a superior contender to solar when it becomes practical?

The consensus points to no. Researcher Eric Chaisson from Harvard University suggests that, even if global energy demands grow slowly, the waste heat produced could contribute to a 3°C increase in global temperatures over the next three centuries. This is due to heat generated as energy is consumed, from boiling a kettle to powering computing devices.

In contrast, with solar—and also with wind and wave energy—waste heat is inherently part of the energy harnessed, preventing any additional heat exacerbation. This essential difference plays a vital role in climate management.

As Chaisson emphasized, “[Carl] Sagan taught me, and I share with my students, that any intelligent civilization must eventually harness the energy of its parent star in totality.” He posed this relevant observation back in 2012, indicating the fundamental course to sustainable energy must focus on solar.

Although three centuries may seem far off, the implications of waste heat are already evident regionally. Research indicates that summer maximum temperatures in Europe have increased by 0.4°C due to waste heat and that some industrial areas may experience temperature rises of almost 1°C by 2100—effects not fully represented in current climate models.

The fundamental conclusion remains that solar, along with wind, offers the potential for sustainable energy for centuries ahead without inflicting catastrophic warming effects. In contrast to Wright’s assertions, the data points clearly indicate the capacity of renewable sources to meet our energy requirements responsibly and effectively.