Renewable Energy vs Sustainable Energy: What’s the Difference?

30 April, 2025

As climate change accelerates and global leaders pursue net-zero targets through policies like the EU Green Deal¹, solving the climate and energy crisis is one of the most essential undertakings of the 21st century. Perfect solutions will be hard to come by, due not only to drastic differences in political and public support for sustainable energy throughout the world, but the extensive knowledge required to address the many challenges associated with the global energy landscape.

“Renewable energy” and “sustainable energy” are often used interchangeably, even among industry experts and veterans. There is some overlap between the two, as many sustainable energy sources are also renewable. However, these two terms are not exactly the same.

A clear understanding of renewable energy versus sustainable energy can help:

• Students make the right college and career choices based on their interests
• Energy industry leaders make the correct decisions based on their organizational objectives
• Policymakers craft appropriate, effective legislation
• Consumers advocate for and adopt the energy methods they find most suitable

What Is Renewable Energy?

Produced from existing resources that naturally replenish renewable energy² can be a much more abiding solution than our current top energy sources. Unlike fossil fuels, renewables are increasingly cost-efficient³, and their environmental impacts⁴ are far less severe. By taking advantage of the earth’s ability to grow and recycle organisms, renewable power sources will theoretically be able to supply our energy needs indefinitely.

Renewable energy is defined by the time it takes to replenish the primary energy resource, compared to the rate at which energy is used. This is why traditional resources like coal and oil, which take millions of years to form, are not considered renewable. On the other hand, solar power can always be replenished, even though conditions are not always optimal for maximizing production.

Under this definition, examples of renewable energy sources include:

• Biomass: Organic material that is burned or converted to liquid or gaseous form. Biomass from trees was the leading source of energy in the United States before the mass adoption of fossil fuels. Modern examples of biomass include ethanol and biodiesel, which are collectively referred to as biofuels. However, their sustainability depends on production lifecycle factors like land use, water consumption, and emissions. Advances in second-generation biofuels, which use non-food crops and agricultural waste, aim to address these concerns, reducing competition for land and improving overall carbon efficiency⁵.
• Geothermal Energy: Heat produced by decaying radioactive particles found deep within the earth. Next-generation geothermal technologies such as superhot rock geothermal are being developed to significantly increase capacity and efficiency, with the potential to meet a larger share of global electricity demand by 2050⁶.
• Hydropower: While hydropower used to be the largest source of renewable electricity due to its reliability, solar has now surpassed it in installed capacity. Hydropower remains a major contributor to global renewable generation but faces growth challenges due to environmental concerns and site limitations.
• Solar: Solar photovoltaic (PV) technology converts sunlight directly into electricity and has been the fastest-growing renewable energy source in recent years. Solar’s rapid expansion⁷ is driven by improved affordability, viability, and demand, but deployment can require significant land area and effective storage solutions to address intermittency.
• Wind: Wind turbines harness wind’s natural kinetic energy to generate electricity. Wind power continues to grow globally, though development faces challenges in some regions due to permit issues and grid connection challenges. Wind is often integrated with other renewables for a more stable energy supply.

What Is Sustainable Energy?

Sustainable energy sources can maintain current operations without jeopardizing the energy needs or climate of future generations. The most popular sources of sustainable energy⁸, including wind, solar and hydropower, are also renewable.

Biofuel is a unique form of renewable energy, as its consumption emits climate-affecting greenhouse gasses, and growing the original plant product uses up other environmental resources. However, biofuel remains a major part of the green revolution. The key challenge with biofuel is finding ways to maximize energy output while minimizing the impact of sourcing biomass and burning the fuel.

Even with resources that are both renewable and sustainable, the need for storage, transmission infrastructure, and equitable grid access can present hurdles.

It is a promising but nuanced option, and the answer isn’t as simple as transitioning from so-called “dirty” resources to sustainable ones. In addition to the challenges around sourcing resources⁹, not all sustainable solutions can be used in every situation. Their efficiency and/or effectiveness can depend on factors such as climate, geography, and local infrastructure. For instance, wind is produced by temperature changes in the air, which aren’t consistent across the planet. In the U.S., this means that the best place to put wind farms¹⁰ is in the Midwest, the Texas region, or offshore. How do we ensure this energy fairly provides for other regions, like the Northeast?

Furthermore, disparities in regulations and target goals can create a problem where the best place to produce energy may not have the public interest or infrastructure necessary to support it. For example, a windy state may struggle to pass legislation for financing the construction of turbines, while its neighbor may be eager for a nearby source of clean energy. How do we navigate such situations in a way that allows consumers to get what they want, no matter where they live?

While new technologies, such as grid-scale battery storage and smart distribution networks, are helping bridge these gaps and making renewable energy more accessible across regions, there is much more work to do. Answering these and other questions requires the advanced critical thinking skills and social, political and economic awareness that a master’s degree in sustainable energy can provide. It will take more to support long-term adoption of renewable and sustainable resources than technical knowledge alone.

The Renewable Energy vs. Sustainable Energy Debate

Energy leaders must understand the nuances between renewable and sustainable energy and use them accurately in legislation. Not only will the precise use of language benefit consumers, allowing them to understand the implications of their energy choices, but it will also help officials ensure their policies accurately reflect their objectives.

For example, a policymaker who drafts a green bill only using the term “renewable energy” may subvert the effect of their own legislation by failing to account for the potential environmental impact of energy sources like biofuels.

Additionally, by using these terms appropriately, energy leaders can ensure their initiatives resonate with public values, increasing the likelihood of continuous national support. As of 2023, 82% of Americans favor expanding solar power and 75% support more wind energy¹¹, with majorities in both major political parties backing these measures. While Democrats are generally motivated by concerns over climate change, Republicans often cite economic benefits such as job creation and energy independence as key reasons for their support. This bipartisan consensus underscores a positive outlook for sustainable energy and highlights the importance for policymakers, private sector leaders, and nonprofits to develop comprehensive strategies that address both environmental and economic priorities.

The question then becomes: How do we go from simply supporting sustainable energy to widespread adoption? The answer is multifaceted, but higher education plays a significant role.

Energy professionals must understand how energy creation, distribution and consumption are affected by factors such as:

• Geography: Where and how can we obtain energy in ways that provide for efficient use, reduce environmental impact and remain cost-effective?
• Economics: How do we finance the transition to sustainable energy sources? How does the cost of creating and distributing sustainable energy affect the rate of adoption? What about areas with little money to invest in sustainable energy?
• Availability: How do we provide sustainable energy to areas less likely to produce it? How do we account for the earth’s natural shifts in resources when quantifying and meeting our energy needs?
• Politics: How do we navigate political interests and arguments for and against sustainable energy?

Even those currently in the industry may find themselves bewildered by the field’s rapid pace and myriad influences. They need the opportunity to build on their existing knowledge and skills in order to address the needs of now and the future.

A master’s degree can introduce energy sector professionals, both experienced and new, to the various issues surrounding the energy crisis. Successfully completing courses that cover multiple aspects of the energy industry, including but not limited to its organization, markets, end-use, policy, financing and global governance, prepares students to tackle some of the biggest energy and climate challenges of today and tomorrow.

About the MA in Sustainable Energy (online) Program at Johns Hopkins SAIS

Provided by a top global university, the Master of Arts in Sustainable Energy (online) at Johns Hopkins School of Advanced International Studies (SAIS) was created to help professionals gain the expertise needed to answer questions about how we can become more effective in our transition to sustainable energy. Students have the opportunity to improve their base of knowledge and their critical thinking skills, helping them rise to leadership positions in their respective fields. This program equips graduates with the interdisciplinary expertise needed to lead energy transitions that are technically sound, economically viable, and socially equitable.

Developed with input from expert faculty, industry leaders and sustainable energy employers, the program and its courses are taught by highly experienced researchers and professionals. Students in the Johns Hopkins SAIS benefit not only from the expertise and industry connections of our faculty but also from our network of 230,000+ alumni.

Disclaimer: This content has not been peer reviewed and is for informational purposes only.

Sources

All sources retrieved April 2025

1. European Commission – European Green Deal
2. International Energy Agency – 2024 Renewables Analysis
3. International Renewable Energy Agency – Renewable Power Generation Costs in 2023
4. American Data Exchange Corporation (ADEC) Environmental, Social, and Governance – Environmental Impacts of Renewable Energy Sources
5. Fast Company – The Future of Bioenergy: What 2025 and Beyond Hold for Biomass and Carbon Capture
6. Clean Air Task Force – An Introduction to the Next Clean Energy Frontier: Superhot Rock and the Future of Geothermal
7. Ember Energy – Global Electricity Review 2025
8. United Nations Economic Commission for Europe – Pathways to Sustainable Energy
9. Green European Journal – Up in Smoke: The Biomass Energy Paradox
10. Environmental and Energy Study Institute – Renewable Energy
11. Pew Research Center – Majorities of Americans Prioritize Renewable Energy, Back Steps to Address Climate Change