Is it actually possible to run the entire world on renewables?
Yes, according to a large and growing body of peer-reviewed research. A landmark 2022 review of over 100 studies concluded that 100% renewable energy systems are feasible worldwide at low cost [2]. The key is combining multiple technologies: solar and wind as the backbone, plus energy storage (like pumped hydro and batteries), high-voltage transmission lines to balance supply across regions, and electrifying transport and industry [2][3].
One detailed global model found that a 100% renewable system covering power, heat, transport, and desalination could meet all demand by 2050, while reducing total primary energy use by 50% through efficiency and direct electrification [4]. The model showed that such a system is not only technically possible but also cost-optimal—meaning it would be the cheapest way to run the global energy system [4].
Even the most ambitious climate targets are within reach: a separate analysis found that reaching 75–99% renewable energy in the global mix could keep warming well below 1.5°C, potentially as low as 1.1°C [1]. So the answer is a clear yes—but it requires a coordinated, global effort.
What are the biggest challenges to getting to 100%?
The main challenge is not technology or cost—it's the variability of wind and solar. Because the sun doesn't always shine and the wind doesn't always blow, a 100% renewable grid needs massive energy storage to cover periods of low generation that can last days or even weeks [3]. One study of Australia's grid found that adding electric vehicles (which increases electricity demand by 40%) could be handled with only a 4–8% increase in electricity cost—but only if most charging happens outside the evening peak. If everyone plugs in at 6 PM, costs jump by 18% [3].
Another major hurdle is the sheer scale of investment required. The same analysis that showed 100% renewables is feasible also noted that current G20 country commitments would need to be supplemented by 80% more private investment to meet the 1.5°C target [1]. This means trillions of dollars in new solar farms, wind turbines, transmission lines, and storage facilities must be built within the next 25 years.
Finally, there are political and social barriers. The research field itself faced strong skepticism early on, and institutional inertia at bodies like the International Energy Agency and IPCC has slowed adoption of 100% renewable pathways [2]. Issues of energy justice—ensuring developing countries aren't left behind or forced into unfair transitions—also need to be addressed [1].
What does a realistic path to 100% look like?
A realistic path involves three key pillars: massive electrification of transport, heating, and industry; building a global or regional supergrid to share renewable power across time zones and weather patterns; and deploying all forms of energy storage at scale [2][4][5].
One study found that a global electricity grid connecting 14 world regions with ultra-high-voltage direct current (UHVDC) transmission lines could reduce the cost of a 100% renewable system by 20% compared to isolated national grids [5]. This is because the sun is always shining somewhere, and the wind is always blowing somewhere—so interconnecting regions smooths out the variability.
The same global model that showed 50% energy savings also emphasized the role of 'Power-to-X'—using renewable electricity to produce hydrogen and synthetic fuels for sectors like shipping and heavy industry that are hard to electrify directly [4]. This is not a single technology solution; it's a systems approach that combines solar, wind, storage, transmission, and sector coupling.
Crucially, the transition doesn't require 100% renewables overnight. The analysis found that staying within 1.5°C warming requires only 58–77% renewable energy in the global mix, and 2.0°C requires 62–83% [1]. The final push to 100% can happen more gradually, as storage costs fall and grid flexibility improves.
Sources used in this answer
Development of integrated model and framework for sustainable energy resources and systems planning
To stay within 1.5°C warming, the world needs 58–77% renewable energy in the global mix; 75–99% could keep warming as low as 1.1°C, but requires extreme investment and effort.
On the History and Future of 100% Renewable Energy Systems Research
A comprehensive review of over 100 studies concludes that 100% renewable energy systems are feasible worldwide at low cost, with solar and wind as central pillars.
Fully electrified land transport in 100% renewable electricity networks dominated by variable generation
Adding 100% electric vehicles to a 100% renewable grid increases electricity demand by 40% but only raises costs by 4–8%, unless most charging occurs during the evening peak (then costs rise 18%).
Low-cost renewable electricity as the key driver of the global energy transition towards sustainability
A global 100% renewable energy system covering power, heat, transport, and desalination is technically feasible and cost-optimal, reducing total energy use by 50% compared to business-as-usual.
Global Electricity Interconnection With 100% Renewable Energy Generation
A global interconnected electricity grid with 100% renewables could reduce system costs by 20% compared to isolated regional grids, using ultra-high-voltage direct current transmission.