WATCH: Can we power the world with only clean energy? – Simon Clark

Discover how energy sources contribute to global demand, with renewables and nuclear comprising 17.8% in 2023, aiming for net zero.


Date Posted: 2025-03-16 18:24:43 | Video Duration: 00:24:44


As the world grapples with the need for sustainable energy, understanding the current landscape of energy consumption and the path to a cleaner future becomes imperative. In 2023, the global energy demand was met predominantly by fossil fuels, with oil, coal, and natural gas together accounting for the vast majority. However, the journey toward a cleaner, more sustainable energy system is underway, albeit with significant challenges and misconceptions.

Current Energy Sources and Challenges

In 2023, oil was the largest contributor to global energy consumption, supplying 35.6% of the total demand. Coal followed closely at 29.7%, and natural gas accounted for 26.2%. Renewable sources, including solar, wind, and hydroelectric power, contributed a modest 6.7%, while nuclear energy provided 1.8%. Together, these low-carbon energy sources accounted for just 8.5% of the total energy used worldwide.

This reliance on fossil fuels poses a significant challenge in reducing carbon emissions. To achieve net-zero emissions, the world must drastically increase the share of clean energy from its current 8.5% to 100%. This task seems daunting, as illustrated by a simple calculation showing that replacing the current energy demand with wind power alone would require approximately 30 million wind turbines, occupying vast swaths of land equivalent to the agricultural areas of the United States.

The Efficiency Argument for Clean Energy

One critical factor often overlooked in the discussion of clean energy is the concept of energy efficiency. Traditional energy systems incur significant losses at every stage, from primary energy sources to final usable energy. For example, burning coal to produce electricity results in two-thirds of the primary energy being lost as heat. In contrast, renewable energy systems, such as wind and solar, do not suffer from these inefficiencies.

When accounting for these efficiency differences, the actual contribution of renewables and nuclear energy to global energy supply rises to 17.8%, nearly double the originally perceived figure. This highlights the potential of clean energy systems to meet our needs more efficiently than fossil fuels.

Electrification and Its Implications

The transition to clean energy is not just about replacing fossil fuels with renewables; it involves a fundamental shift toward electrification. Currently, only 20% of final energy demand is in the form of electricity, with the remaining demand split between transportation and heating. Electrifying these sectors can significantly reduce energy consumption by improving efficiency.

Electric vehicles (EVs), for instance, use less than half the energy of gasoline-powered cars, even considering the energy required to produce them. Similarly, air-source heat pumps for heating can achieve efficiencies greater than 100%, as they extract energy from the air. This shift to electrified systems could reduce global energy demand by 40%, according to a 2021 study.

The Path Forward

While the potential for clean energy is significant, achieving a completely clean energy system faces two primary challenges. First, not all applications can currently be electrified, such as aviation and certain industrial processes that require high energy densities. Second, the global appetite for energy continues to grow, increasing by 1-2% annually. Despite these challenges, the share of clean energy in the global mix has been increasing, and as electrification progresses, the demand for primary energy is expected to stabilize.

Ultimately, reaching 100% clean energy may not be feasible due to technological limitations, but achieving a high percentage of clean energy is within reach. This transition will require a combination of renewable sources, nuclear power, and strategic use of technologies like carbon capture. As the world shifts to a more electrified and efficient energy system, the reliance on fossil fuels will diminish, paving the way for a sustainable future.

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