Green, Sustainable, Clean, and Renewable Energy — What Does It All Mean?

Green, Sustainable, Clean, and Renewable Energy

Green, Sustainable, Clean, and Renewable Energy — What Does It All Mean?

  1. Green Energy
  2. Sustainable Energy
  3. Clean Energy
  4. Renewable Energy
  5. Comparing Types of Energy
  6. Ambiguous Energy Classifications
  7. Choosing an Energy Source

Developing and deploying alternative forms of energy has become a vital concern over the past several years. Some forms of green energy have been around for years, even decades — but with the signing of the Paris climate accords in 2016, the vast majority of the countries around the world committed to limiting carbon emissions to try to keep the global temperature increase under 2 degrees Celsius. More recently, the United Nations' Intergovernmental Panel on Climate Change released a paper warning of catastrophic climatic effects if we do not hold the global temperature increase to less than 1.5 degrees Celsius.

Consequently, many Americans want to change the way energy is sourced. According to a recent opinion poll done on behalf of the Edison Electric Institute, 70% of Americans agree that in the near future, we should source 100% of our energy from renewable resources. And the Pew Research Center has found that two-thirds of Americans prefer to prioritize alternative energy sources over fossil fuels. Alternative energy sources can include green, renewable, clean, and sustainable energy.

But what are these different types of energy? The terms green energy, clean energy, renewable energy, and sustainable energy tend to appear in the news and on company websites as if interchangeable — but in reality, they have distinct meanings. Below, we'll explain some of the differences between these terms, offer some examples and explain how customers can be part of the alternative energy movement.

Green Energy

Green energy is energy that emits relatively small amounts of pollution in the form of greenhouse gases, radiation, or chemical contaminants. Though green energy can affect the environment, the impact is typically localized and occurs on a small scale. It should not threaten plant or animal species with habitat loss, population reduction, or extinction.

At Shipley Energy, we provide green and renewable options to some of our Pennsylvania customers — we'll say more about renewable energy below. We offer customers the opportunity to participate in our partnership with renewable energy providers. Through this program, customers can offset their fossil fuel usage by funding renewable and sustainable energy projects elsewhere — typically a mix of hydropower, solar energy, and wind energy. Our renewable energy programs exceed the requirements outlined in Pennsylvania's Renewable Portfolio Standard (RPS) and the Alternative Energy Portfolio Standard (AEPS), and customers can be sure their money is going to reliable, high-quality energy projects.

Sustainable Energy

Sustainable energy is energy that renews itself automatically. In this way, it can remain a viable energy source across many generations.

Sustainable Energy

Wind and solar energy are examples of sustainable energy. Humans cannot deplete stores of solar energy or wind energy. The sun will keep producing light energy until it dies, and the rotation of our planet will keep generating wind for as long as the planet exists.

Currently, an impressive array of solar parks and wind farms generate sustainable energy across the United States and around the world. Egypt is at work on the construction of a solar park that will be the largest in the world when it opens, producing 1.8 gigawatts of energy. Longyanxia Dam Solar Park in China produces enough sustainable energy to power nearly 200,000 homes. Closer to home, the Solar Star power station in California is the largest solar park in the Western hemisphere, producing 5709 megawatts of power. Even Ukraine's Chernobyl, the site of the infamous nuclear disaster, now has a small solar park.

Meanwhile, Jiuquan Wind Power Base in China is the world's largest wind farm, featuring 7,000 wind turbines and producing 20 gigawatts of energy. Shepherd's Flat Wind Farm in eastern Oregon is the fifth-biggest wind farm in the world, producing 845 megawatts of energy. And the vast Texas landscape is home to several prominent wind farms, including Roscoe Wind Farm, Horse Hollow Wind Energy Project, and Capricorn Ridge Wind Farm.

Tidal energy and geothermal heat energy are sustainable as well since the interactions of the moon and the earth will always produce tides, and the mantle of the earth will always give off heat that we can access in regions of volcanic and tectonic activity. In Iceland, an area of substantial volcanic activity, geothermal energy supplies 90% of residents' electricity needs. In the United States, which is the world's largest producer of geothermal energy, some cities harness this energy and pump it under sidewalks and streets to help melt ice and snow.

Experts disagree about how to classify nuclear energy, but many classify it as sustainable energy. Over the scale of human existence on earth, it is not possible to use up the amount of nuclear energy available to us. Nuclear energy does not renew itself, however — once it is used up, it is gone as well.

Fossil fuels, of course, are examples of unsustainable energy — we can deplete them. Petroleum, or crude oil, formed over millions of years as the dramatic heat and pressure beneath the earth's surface compacted ancient aquatic organic matter such as plants, algae, and plankton into a carbon-rich liquid. Coal and natural gas formed in much the same way, over millions of years, under different amounts of subsurface heat and pressure. The planet does not continually produce more petroleum, coal, or natural gas, so after we have extracted all the oil from beneath the earth's surface, it will be gone.

Clean Energy

Clean energy is energy that emits negligible amounts of pollution in the form of carbon dioxide, radiation, or chemical contaminants. Zero-carbon energy sources are forms of clean energy. The minuscule emissions from clean energy should have minimal to no impact on the surrounding environment.

Wind and solar energy are examples of clean energy because their production emits no pollution into the environment. The energy that comes from burning fossil fuels, on the other hand, is not clean energy because it releases harmful contaminants into the air. Though wind turbines can cause problems for bats and birds, they still have minimal negative overall affects on the environment.

One ambitious policy step the United States may consider taking in the future is the building of a clean energy grid. Right now, the energy in our energy grid comes from a tremendous variety of sources, from the sustainable energy of wind and solar farms to the energy produced from fossil fuels. And fossil fuels make up a significant majority of the energy sources for our electrical grid. As the National Resources Defense Council (NRDC) reports, for the past 125 years of its existence, the U.S. power grid has been designed around large fossil fuel and nuclear energy plants that could provide immense supplies of power to major American cities.

A clean energy grid would change that. The NRDC is working in partnership with the U.S. Federal Energy Regulatory Commission (FERC) to create changes that will lead to a cleaner and more efficient energy grid. The NRDC also works with the government and with energy companies to make sure new sources of energy preserve delicate ecosystems and leave plenty of habitat areas in which wildlife can thrive.

The U.S. Department of Energy (DOE) is also currently engaged in the Clean Energy Manufacturing Initiative (CEMI). This initiative, established in 2013, seeks to support U.S. manufacturing while developing cleaner processes for use throughout the industry. The DOE has increased funding for manufacturing research and development to come up with innovative clean solutions that will help manufacturing grow and protect the environment at the same time.

Renewable Energy

Renewable Energy

Renewable energy is theoretically exhaustible. However, in practice, it consumes such minimal amounts of resources that it will be viable as an energy source over the long term. Ethanol is a renewable energy source because it comes from sugarcane or corn, and we can grow more of those crops to replenish our stores. At their current level of usage, logs and wood chips could also be considered renewable energy — tree regrowth can replace the wood burned for fuel. This situation could easily change, though — increased deforestation and widespread wood burning could make wood fuel unsustainable in short order.

Energies such as other biodiesels, biomass, and even municipal waste are also forms of renewable energy because we can continue generating more.

Programs like renewable energy certificates, as their name suggests, tend to fall into the category of renewable energy as well, even though these programs typically involve a mix and balance of different energy sources. Under these programs, consumers still receive their oil or natural gas for heating and electricity, and of course, oil and natural gas are not renewable resources. But the energy companies then commit to purchasing the same amount of energy in a sustainable form, such as energy from solar panels or a wind farm. This exchange makes consumers' net carbon consumption zero.

Renewable energy certificates don't change where your energy comes from. They merely support a clean alternative. But supporting a clean alternative has significant benefits. Giving financial support to clean energy projects helps them keep growing and developing. Especially if technologies are new and need to evolve quickly, consistent financial support can be crucial. It also makes the overall supply of energy in the electrical grid a little cleaner, even if your personal supply remains unchanged. The EPA's Green Power Partnership allows consumers to see and potentially choose from green and renewable energy projects around the country.

Green, Sustainable, Clean, and Renewable Energy Compared

Now that we've discussed different types of energy, let's recap the four sections on green, sustainable, clean, and renewable energy above.

Green energy has a small negative impact on the earth's atmosphere and environment. If there is one umbrella term that can encompass all four of the types of energy we've described, green energy is it. The differences between clean and green energy are differences of degree. Clean energy takes the idea of green energy a step further — it makes almost no negative impact on the earth's atmosphere and environment.

The difference between green and renewable energy involves the possibility of replenishment. Renewable energy comes from sources that the earth can naturally replenish, such as crops and biomatter. Sustainable energy comes from sources that don't need to be replenished because they can never be depleted, such as sunlight and wind energy.

As you can see, renewable and sustainable energy are more or less subsets of clean energy. Wind and solar power are examples of sustainable energy because they cannot be depleted. But they are also examples of clean energy because they do not pollute the atmosphere or damage the environment.

Here are a few examples of different fuels and the types of energy they represent:

  • Coal: Not green, clean, renewable, or sustainable.
  • Oil: Not green, clean, renewable, or sustainable.
  • Hydropower that could damage the environment: Not green, clean, renewable, or sustainable.
  • Hydropower designed not to damage the environment: Green, clean, and sustainable.
  • Solar energy: Green, clean, and sustainable.
  • Wind energy: Green, clean, and sustainable.
  • Geothermal energy: Green, clean, and sustainable.
  • Wave and tidal energy: Green, clean, and sustainable.

Ambiguous Energy Classifications

Some energy experts disagree about the nuances of these classifications. For example, many industry leaders would call solar energy sustainable energy because it can never be used up. But others counter that although the sun's energy cannot be diminished, the production of solar panels creates significant environmental impacts. These people say that solar energy should not be considered sustainable because its creation is sourced unsustainably.

Similarly, some scientists might classify nuclear energy as clean energy because it does not produce harmful pollutants — except that if something goes wrong, nuclear plants could potentially produce staggering amounts of hazardous radiation. And disposal of nuclear waste is a concern, as is the possibility that nuclear plants might one day become involved in the development of nuclear weapons.

Some confusion exists about how to classify hydropower as well. Hydropower — the electricity sourced from dams — provides about 20% of the energy used around the world. Hydropower is often classified as sustainable energy because we cannot use up the earth's water supply.


But some people argue that hydropower has too many social and environmental costs to be considered a sustainable or renewable resource. Dams can cause permanent destruction to local ecology — they cause dramatic changes in water flow, sometimes leading to drought, and their construction disrupts local ecosystems. They can lead to substantial deforestation and loss of biodiversity, as well as loss of livelihood for fishers and farmers.

Even ethanol, which is generally considered a renewable energy source, is grown with fertilizer, which is often a petroleum byproduct. And growing corn for ethanol can diminish the rest of the corn market, as well as encourage harmful agricultural practices.

Choosing an Energy Source

Generally speaking, clean, sustainable energy sources represent the most significant strides forward in terms of preserving our planet's resources and protecting ourselves from further climate change. But at the moment, green and renewable sources still make valuable contributions, and they may be much more practical to implement. We are not yet ready to power all our homes, businesses, hospitals, factories, and so on with wind or solar energy. But using renewable energy certificates to support those energy sources represents a useful step forward. And the future will likely bring many more advances in the field of clean, green energy.

Contact Shipley Energy for Residential and Commercial Green Energy Services

Whether you own a home or are looking for green energy services for your business, Shipley Energy has what you need. We've been in business for over 85 years, and we are industry experts in both residential and commercial energy. Our green energy options help customers support green and renewable energy projects while still receiving the same trusted services we've been providing for decades. We also offer a convenient way for customers to check our rates on our website.

Contact us online or give us a call at 1-866-789-5560 to learn more about commercial or residential green energy.

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