What Is Renewable Energy?
Unlike fossil fuels, which are exhaustible, renewable energy sources regenerate and can be sustained indefinitely. Renewable energy comes from natural resources such as sunlight, wind, moving water, plant material, and geothermal heat. Renewable energy is naturally replenished within your life time or within a few generations. Currently, renewable energies make up 8% of the energy used in the United States. Most renewable energy is used for making electricity.
The other type of energy is non-renewable energy. It is any kind of energy that is derived from fossil fuels, such as oil, or is used only once and then not replenished naturally within a few human lifetimes.
The use of renewable energy is not new. More than 150 years ago, wood, which is one form of biomass, supplied up to 90% of our energy needs. As the use of coal, petroleum, and natural gas expanded, the United States became less reliant on wood as an energy source. Today, we are looking again at renewable sources to find new ways to use them to help meet our energy needs.
In 2011, consumption of renewable sources in the United States totaled about 9 quadrillion Btu — 1 quadrillion is the number 1 followed by 15 zeros — or about 9% of all energy used nationally. About 13% of U.S. electricity was generated from renewable sources in 2011.
Over half of renewable energy goes to producing electricity. The next largest use of renewable energy is biomass (wood and waste) for the production of heat and steam for industrial purposes and for space heating, mostly in homes. Biomass also includes biofuels, such as ethanol and biodiesel, used for transportation.
Renewable energy plays an important role in the supply of energy. When renewable energy sources are used, the demand for fossil fuels is reduced. Unlike fossil fuels, non-biomass renewable sources of energy (hydropower, geothermal, wind, and solar) do not directly emit greenhouse gases.
Why Don’t We Use More Renewable Energy?
In the past, renewable energy has generally been more expensive to produce and use than fossil fuels. Renewable resources are often located in remote areas, and it is expensive to build power lines to the cities where the electricity they produce is needed. The use of renewable sources is also limited by the fact that they are not always available — cloudy days reduce solar power; calm days reduce wind power; and droughts reduce the water available for hydropower.
The production and use of renewable fuels has grown more quickly in recent years as a result of higher prices for oil and natural gas, and a number of state and federal government incentives, including the Energy Policy Acts of 2002 and 2005. The use of renewable fuels is expected to continue to grow over the next 30 years, although EIA projects that we will still rely on non-renewable fuels to meet most of our energy needs.
How Do We Measure Renewable Energy?
Each of the energy sources we use is measured, purchased, and sold in a different form. Many units of measurement are used to measure the energy we use. Learn more about converting energy units in the Units and Calculators section.
Teachers, students, and families are encouraged to learn more about energy science and the principles of resource sustainability that apply to our daily lives. For more information on sustainability, visit National Grid.
Brief History of Energy
In the United States today, approximately 70% of the energy we use comes from fossil fuels. We do, however, have alternatives to the overuse of fossil fuels through substituting renewable energies for power production and we can conserve energy or become more efficient with the energy we consume.
Where does the energy you use come from?
Natural gas is a form of energy that many of us often use in our homes, schools, and businesses for heating and cooking. Natural gas is found deep underground and is delivered to buildings through underground pipes. It is a non-renewable fossil fuel.
Electricity is often named as a source of energy. It is not a source of energy, however, but is instead an energy carrier or a secondary source of energy. Whenever you use anything that runs on electricity, a power plant is generating that electricity from a primary source of energy. Often the source of our electricity comes from the combustion of a fossil fuel such as coal, oil, or natural gas or from nuclear energy.
Since fossil fuels and nuclear energy are nonrenewable resources, this means that once we use them up, they are gone forever. We can make these resources last longer by conserving energy and not wasting it, and by using energy from renewable resources that will not run out. You or someone you know is probably already using electricity made from solar panels, wind turbines, or a hydroelectric power plant!
Think about it: Did you use hot water or electric lights today? Did you talk on a cell phone or text someone? How was your food cooked? Energy helped make all these things possible.
No matter where your energy comes from, using it sustainably helps keep our environment healthy.
This is because all energy production and use affects the environment. The less pollution we add to our environment, the better the health of the Earth will be. Adding renewable energy to our state’s Energy Portfolio will help to meet energy sustainability goals.
What does "sustainable" mean, and why does it matter?
If you look up the definition of "sustainable," you might find this: "able to be sustained." Unless you know what sustain means, that doesn't help much, does it?
"Sustain" means to continue something or keep it going, so "sustainable" means something that has the ability to continue. A Sustainable Energy World is a world where energy is used in ways that allow the earth to function as a safe and healthy home for humans, plants, and animals.
When you use energy sustainably, you help control pollution, reduce CO2 emissions, and preserve our energy resources.
You also help conserve other types of resources. It takes a tremendous amount of natural resources (like water, land, wood, and other building materials) to build a power plant. Saving energy delays the need for new power plants.
Using energy sustainably now will ensure we can continue to use it in the future without running out or damaging the environment beyond repair. This is one of the most important things we can do to keep our planet healthy and preserve the earth’s resources for ourselves and for future generations.
What is unsustainable behovior and how do I avoid it?
Your carbon footprint is the amount of carbon dioxide (CO2) that is released into the atmosphere as a result of the energy used for your everyday activities. The food you eat, what you buy, and what you throw away all affect your carbon footprint. That’s because it takes energy to manufacture, package, and transport everything that you eat or use.
Why change your carbon footprint?
Many scientists believe that the CO2 in our atmosphere is increasing as a result of human activities. This includes the burning of fossil fuels for energy. Extra CO2 in the atmosphere traps heat, causing the earth’s climate and weather to vary beyond the average mean temperature of the last few decades.
Because all of the earth’s natural processes are tied to temperature, some scientists are concerned that the climate change may harm its ecosystems. Reducing your carbon footprint can help reduce the CO2 in the atmosphere and keep the earth healthy.
Ideas to reduce your carbon footprint:
What is STEM?
STEM—short for Science, Technology, Engineering, and Math—is considered crucial subject matter for today’s students and critical to their future success in the global economy.
Why does Science Matter? Science is critical to understanding the world around us. Most Americans feel that they received a good education and that their children will as well. Unfortunately, not many are aware that international tests show that American students are simply not performing well in science when compared to students in other countries. Many students (and their parents!) believe that science is irrelevant to their lives.
Innovation leads to new products and processes that sustain our economy, and this innovation depends on a solid knowledge base in science, math, and engineering. All jobs of the future will require a basic understanding of math and science. The most recent ten year employment projections by the U.S. Labor Department show that of the 20 fastest growing occupations projected for 2014, 15 of them require significant mathematics or science preparation to successfully compete for a job.
This is why Science Matters. Quality learning experiences in the sciences—starting at an early age—are critical to science literacy and our future workforce. This is what STEM does for students.