Energy Education: The Basics
Energy is part of nearly everything we do, from heating and cooling our homes to powering transportation, businesses and technology. Understanding where energy comes from and how we use it is an important first step toward creating energy systems that are more efficient, resilient and regenerative.
What is sustainable energy?
Sustainable energy meets today’s energy needs while considering the ability of future generations to meet theirs. It looks beyond how energy is generated to consider the broader environmental, economic and social impacts of an energy system.
This means considering the resources used to produce energy, the infrastructure needed to generate and distribute it and what happens to equipment and materials at the end of their useful life.
What is Energy Efficiency?
Energy efficiency means using less energy to provide the same product, service or result.
For example, an LED light bulb can produce the same amount of light as a traditional incandescent bulb while using significantly less electricity. Energy-efficient buildings, appliances and equipment help reduce energy use without requiring people to give up the services they rely on.
What is Energy Conservation?
Energy conservation means reducing energy use through our actions and behaviors.
Examples include turning off lights when leaving a room, unplugging electronics when they are not in use and adjusting thermostat settings to reduce heating or cooling demand.
The difference is simple: Energy efficiency focuses on using energy more effectively, while energy conservation focuses on using less energy.
What is Renewable Energy?
Renewable energy comes from sources that are naturally replenished on a human timescale. Examples include sunlight, wind, flowing water and certain forms of biomass and geothermal energy.
Fossil fuels, including coal, oil and natural gas, are non-renewable. They formed from organic material over millions of years and are consumed much faster than natural processes can replace them.
Renewable vs. Sustainable Energy
Renewable and sustainable energy are related, but they are not exactly the same.
Renewable describes whether an energy source can naturally replenish itself.
Sustainable takes a broader view. It considers the long-term impacts of the entire energy system, including how raw materials are obtained, how energy infrastructure is manufactured and built, how energy is generated and distributed and what happens to materials and equipment at the end of their useful lives.
An energy source can therefore be renewable while still having environmental and social impacts that need to be considered.
What is Regenerative Energy?
Sustainable energy seeks to meet current needs while minimizing harm and preserving resources for the future. Regenerative energy goes further by asking how our energy systems can help restore and strengthen the living systems and communities they depend on.
Rather than following a linear pattern of extracting resources, using them and creating waste, regenerative systems emphasize circular flows, where resources remain in productive use and natural systems have the opportunity to renew themselves.
Over the long term, sustainability depends on regeneration. Resources and systems cannot simply be preserved indefinitely. They must also have the capacity to renew, recover and thrive.
Regenerative energy asks us to consider not only how we can do less harm, but how our energy choices can create lasting positive value.
Explore Energy Sources
Energy comes from many different sources, each with its own technologies, applications and impacts.
Solar Energy
Solar energy is energy from the sun that can be used to produce heat or generate electricity.
Solar photovoltaic (PV) panels convert sunlight directly into electricity. When sunlight reaches the semiconductor materials inside a solar cell, its energy causes electrons to move, creating direct current (DC) electricity. An inverter then converts the DC electricity into alternating current (AC), the type of electricity commonly used in buildings and on the electric grid.
Wind Energy
Wind energy uses the movement of air to generate electricity.
Wind pushes against specially designed turbine blades, causing them to rotate. The spinning rotor transfers mechanical energy through the turbine to a generator, which converts that energy into electricity.
Hydropower
Hydroelectric power, or hydropower, uses moving water to generate electricity.
In many hydropower systems, water stored behind a dam is released through large pipes called penstocks. The moving water spins a turbine connected to a generator, converting the water’s energy into electricity.
Not all hydropower systems require large dams. Some systems use the natural flow of rivers or other moving water.
Geothermal Energy
Geothermal energy comes from heat within the Earth.
In areas where underground heat is accessible, hot water or steam can be used directly for heating or to generate electricity.
Buildings can also use ground-source heat pump systems, sometimes called geothermal heat pumps. These systems take advantage of relatively stable temperatures below the Earth’s surface to efficiently heat and cool buildings.
Biomass
Biomass is organic material from plants and animals that can be used as an energy source.
Examples include wood, agricultural materials, food waste and other organic materials. Plants store energy from the sun through photosynthesis, and that stored energy can later be converted into heat, electricity or fuels.
Biomass can be renewable when resources are replenished responsibly, but its overall environmental impact depends on factors such as where the material comes from, how it is produced and how it is used.
Nuclear Energy
Nuclear energy comes from the nucleus, or core, of atoms.
Nuclear power plants generate electricity through a process called nuclear fission, in which atoms such as uranium are split and release energy as heat. That heat is used to produce steam, which turns a turbine connected to a generator.
Nuclear power plants do not emit carbon dioxide during electricity generation, but nuclear energy presents other considerations. Uranium is a finite resource, and used nuclear fuel and other radioactive materials require careful handling and long-term management.
Because uranium is not replenished on a human timescale, nuclear energy is generally classified as a non-renewable energy source.
Learn More
Want to explore energy further? These organizations offer additional educational resources, data and information about energy technologies and energy use:
- U.S. Department of Energy — Energy.gov
- U.S. Energy Information Administration — EIA.gov
- The NEED Project — NEED.org