What Is Clean Energy? Is It Truly Clean?

Written By Teacher: Elizabeth Ward

My name is Elizabeth Ward. I am a former Early Childhood, Elementary, and English as a Foreign Language educator. I have taught third grade Science and Social Studies as well as Kindergarten in both urban and rural Oklahoma public schools. I taught online EFL to students of all ages in China for four years. I also have experience in curriculum development and content design for teachers in the physical and digital classroom. As a former teacher I have a passion for supporting teachers and making their jobs easier. I currently live in the greater Houston area with my husband and four dogs. 

No energy source is completely free of environmental impact, but some are much cleaner than others. Understanding the trade-offs between different energy sources helps students evaluate what "clean energy" really means and how it fits into climate solutions. This topic encourages critical thinking about emissions, resource use, and long-term sustainability. Even  younger students can begin learning about energy types and usage. Third, fourth, and fifth grade students can explore and write about the pros and cons of energy types with this activity. High school students can dive into this series of articles from the Council on Foreign Relations. 

Written By: MIT Environmental Solutions Initiative

The MIT Climate Change Engagement Program, a part of MIT Climate HQ, provides the public with nonpartisan, easy-to-understand, and scientifically-grounded information on climate change and its solutions.

The group of technologies widely considered to be “clean energy” include hydropower, geothermal, solar, wind, nuclear, bioenergy (at least in some circumstances), and even some extremely nascent technologies like ocean wave power. These energy sources are “clean” with regard to climate change because—unlike fossil fuels—when they produce energy they do not emit greenhouse gases, the type of pollution that is warming our planet. The most important of these gases is carbon dioxide (CO2), so “clean” technologies can more precisely be referred to as low-carbon or carbon-free.

Clean energy technologies are in many ways very different from one another, but none directly emit CO2.

“A key word there is directly,” says Jennifer Morris, a principal research scientist at MIT’s Joint Program on the Science and Policy of Global Change and the MIT Energy Initiative. Even if they do not produce emissions during operation, clean energy technologies all have some “embedded emissions,” like those associated with producing their equipment.