Clean, Green, and Renewable Energy: What’s the Difference?
You’re probably familiar with the terms clean energy, green energy, and renewable energy from the news. You may even think that they mean roughly the same thing.
I’m sorry to say that’s not the case. (It’s ok, you’re not alone in that.)
It turns out that each of the three terms differ from one another and have their own specific meaning. They all sound like they’re good for the environment. Some of them are better for the environment than others. These differences are vitally important if we’re going to save the environment and tackle the mounting climate change problems we’re facing. So keep reading as we explore each type of alternative energy to fossil fuels.
What is clean energy?
Clean energy is simply any energy source that doesn’t pollute and release greenhouse gasses like carbon dioxide, methane, or nitrogen monoxide. Clean energy sources are great long-term replacements for fossil fuels because they keep greenhouse gas emissions to minimum levels and don’t pollute the environment around them.
CAN YOU THINK OF ANY ENERGY SOURCES THAT ARE CLEAN?
If you said solar power, wind power, wind turbines, or hydroelectric power (as long as it doesn’t pollute) then you’re correct! Have you ever heard of geothermal energy? Geothermal energy is heat energy taken right from the Earth. The earth’s heat is used to boil water and create steam, which is then used to generate electricity. Think of a coal power plant that runs on the Earth’s natural heat!
In contrast, biomass energy is not a clean energy source. This is because, unlike wind power, biomass energy produces a lot of air pollutants and greenhouse gases. It also doesn’t rate very high in energy efficiency.
What is green energy?
Green energy is any type of energy that comes from a natural source. This means that solar energy, wind energy, and hydro energy are all examples of green energy. The Environmental Protection Agency (EPA) describes green energy sources like wind energy as providing the highest environmental benefit. Like renewable energy (which you’ll read about next), green energy is a great solution towards achieving greater sustainability in our power grid.
And lastly, what is renewable energy?
Renewable energy is any type of energy that comes from natural sources and replenishes itself. Believe it or not, people have already been using renewable energy resources for hundreds of years. Wind farms for generating electricity and transforming the wind into wind power. This renewable electricity is helping us decrease our green house gas emissions.
CAN YOU THINK OF ANY TYPES OF ENERGY THAT WOULD BE CLASSIFIED AS RENEWABLE?
Once again, if you said solar energy or wind energy, then you’re correct! Before cheap and dirty alternatives were available like coal, gas, and oil, people would heat themselves with renewable sources like the sun. Now we use solar panels and wind turbines to harvest the power of Earth’s renewable energy sources.
So what’s the difference between them?
Did you notice there are similarities and significant overlaps among the three types of energy? In fact, the terms are so similar that they’re often used interchangeably everyday even by environmentalists! But there exist small but important differences. These differences are related to their creation, their renewal, and their impact.
CREATION
Renewable energy generates electricity from natural sources. These sources can be replaced completely within a generation. If you’re thinking fossil fuels and natural gas are natural sources, then you’d be correct. However, they take millions of years to replenish, so they’re not renewable energy sources.
Green energy is a subset of renewable energy. It must come from natural sources, but it can’t pollute the environment. Like green energy, clean energy doesn’t (or nearly doesn’t) pollute, but it doesn’t need to come from renewable energy sources.
RENEWAL
As the name implies, renewable energy is renewable! It doesn’t run out and is naturally restored. As a subset of renewable energy, green energy is also renewable, in addition to not having a negative impact on the environment.
Clean energy, though, is separate. Like green energy it doesn’t pollute, but it doesn’t have to come from renewable energy sources. Some consider nuclear energy a clean form of energy that isn’t renewable energy. However, the waste water nuclear energy produces is potentially a pollutant to the surrounding environment, so saying that nuclear is clean energy is a questionable claim.
IMPACT
Lastly, some renewable energy sources can have an environmental impact. For example, the creation of a hydroelectric dam can have harmful or even devastating impacts on its immediate environment and local fauna, while providing renewable energy. Both clean energy and green have no (or negligible) environmental impacts.
Is there a perfect combination?
Energy can fall under one, two, or even three of the categories at the same time. Take solar energy and wind energy for example. These two types of energy are clean (they do not release greenhouse gasses or polluting chemicals), green (they come from natural sources), and renewable (they replenish themselves).
This makes energy sources like wind and solar ideal because they renew themselves and produce electricity and power. They do this in a sustainable way that doesn’t contribute to climate change and is a better solution for generations to come.
In Conclusion
Now you know the similarities and differences between clean, green, and renewable energy. They’re all important improvements upon burning fossil fuels for energy production. Some are better than others, but conversion to any of the three is a step in the right direction towards combatting and countering the effects of climate change. Remember, ideal combinations of the three exists, such as solar power or wind energies, but one or two out of the three isn’t bad either!
Nataly Perez Manrique is a Latin immigrant from Peru. She has a master’s degree in Environmental Engineering from Duke University. She is also an advocate for the eradication of violence against women and the defense of Indigenous peoples’ rights in her home country.
Is Solar Energy Really Green And Sustainable?
After studying and working in HR, André studied sustainability management at Lisbon’s School Of Economics Management. He is responsible for the English speaking market of Youmatter since 2018.
Published at 2019, February 7 th
Is solar energy really zero emissions, clean and sustainable? How much has it grown over the last years? What’s wrong about it? Let’s find out.
Solar Energy And Photovoltaic Panels Today
As you probably know already, solar energy is one type of renewable energy, i.e., an energy that is produced using resources that replenish quicker than the rate at which humankind consumes it.
2017 was a record year for renewable energy because for the first time, over two-thirds of global net electricity growth (178GW) were renewable. Of all renewables, solar photovoltaics (PV) capacity was the fastest-growing (97GW), especially in China. In fact, the U.S., the EU, China, India, and Japan are the nations pushing the most for solar energy growth. They see it as a way to improve economic attractiveness.
But does all this development and growth of the solar energy industry mean it is clean or green to produce?
Why Is Solar Energy Bad?
It’s not very respectful to say solar energy is bad, at least not when compared with other types of energies powered by fossil fuels. Still, it has some downsides that are worth analyzing. We can start by clearing out that solar energy is not zero emissions, clean, or 100% green. But why is that if solar panels receive sun rays and generate electricity through heating without releasing any CO2 or CO2eq? Well, if we take a closer look at solar panels life cycles we’ll realize that they make some pollution and energy consumption during manufacturing and are likely to have more once they get disposed.
Producing photovoltaic panels requires minerals like copper, nickel, and cadmium. For instance, if we think of silver, its supply and demand for photovoltaic purposes are, respectively, ~ 27 billion kg and 242 million kg (in 2017). Other minerals such as lithium or silicon are also at risk of having a demand that outstrips supply today and in the future.
The problem here isn’t really about these minerals being finite resources because there are still many reserves. It is about the mining activities themselves. Indeed, the extraction and the chemical separation processes to get these minerals is very polluting and in many places, like Chile, toxic waste is not responsibly taken care of. Together with other impacts like soil erosion or mercury contamination, mining activities can pollute the air, water, and soils and harm local biodiversity and populations. The mitigation of these and other risks depend on the local sites’ governance practices.
What Are The Advantages Of Solar Energy? The Power Of Solar Panels
Despite the costs of producing solar panels, according to one study, after 5.23 years generating electricity, they will make up for the energy used to produce the system itself. over, solar panels have their financial payback within 19.3 to 34.4 years, depending on the rate of renewable energy feed-in-tariff applied, according to an Irish paper.
In addition, studies back up that electricity production by photovoltaic solar panels is more sustainable than electricity powered by fossil fuels. Still, these calculations depend on the region of production since, for instance, the carbon footprint of a panel produced in China can be up to twice as big compared to panels produced in Europe.
Hence, solar PV technologies are small and can be used anywhere in the world with relatively low operation and maintenance costs. Regarding the problems around the solar panels end of life, as the industry grows recycling sites will grow too and industry players will likely feel encouraged to find new solutions to improve the efficiency of their operations. And the good news is that some minerals, like aluminum, lead, and copper require less energy to be recycled when compared to primary extraction.
Solar Energy And PV Panels: Positive Energy With Downsides
Conclusion: solar energy is not perfect. Manufacturing photovoltaic panels is energy consuming and requires finite Earth minerals that have harsh extraction impacts.
Panels also only produce electricity on peak hours, i.e., when they get over 1000 watts of photovoltaic power. This means solar panels can produce electricity from an average of 4 hours (in the best U.S. states) to 6,5 hours a day, even if it’s sunny all day.
It’s also a good idea to have solar PV technology reducing its carbon emission by powering mines and mineral processing sites, as in Australia or South Africa. Tighter regulations and good government practices are also fundamental to reducing the risks associated with mining activities. Furthermore, the development of the recycling industry for all types of minerals are also crucial steps in minimizing the impacts of the mining and, therefore, the solar energy industries.
In the end, solar energy is easier to set up anywhere in the world and it is becoming increasingly more affordable. If companies and nations want to fulfill their GHG reduction promises, it is important to keep growing their sources of renewable energy and keep creating incentives for solar or wind energy industries to develop. However, it’s still important to consider their side impacts and try to mitigate them so that solving one problem doesn’t mean creating another one.
Renewable Energy
The movement of wind and water, the heat and light of the sun, the carbohydrates in plants, and the warmth in the Earth—all are energy sources that can supply our needs in a sustainable way.
A variety of technologies are used to convert these renewable resources into electricity. Each comes with its own unique set of benefits and challenges; collectively, they represent our best hope in the fight against climate change.
Solar power
How Solar Energy Works
A comprehensive overview of solar power technologies, benefits, costs, and more from the Union of Concerned Scientists, including rooftop solar panels, large-scale solar power plants, and how solar panels work.
Solar energy—power from the sun—is a vast and inexhaustible resource that can supply a significant portion of global electricity needs. In the United States, over two million households already have solar panels on their roof; utilities and companies across the country are also investing in solar farms to capture the sun’s energy at a larger scale.
Solar power is essentially carbon-free. A small amount of pollution is created during the manufacturing process, and disposal is an ongoing challenge; however, the fuel used (the sun) is free, is plentiful, and doesn’t pollute.
Wind power
How Wind Energy Works
Wind turbines harness air currents and convert them to emissions-free power. Plentiful and inexhaustible in the United States and around the world, wind power is one of the fastest growing renewable technologies and has the potential to provide a significant portion of our electricity needs.
Currently, wind provides a relatively small percentage of US power, though it’s expected to grow as more utilities invest in wind farms, and as offshore wind—wind turbines located in the ocean—becomes more common.
Energy storage
How Energy Storage Works
One of the keys to achieving high levels of renewable energy on the grid is the ability to store electricity and use it at a later time.
While not source of energy itself, energy storage technology is a critical component for creating a low-carbon electricity system. The technology takes various forms—older facilities use pumped water, while newer systems deploy lithium-ion batteries—but the fundamental goal is always the same: storing electricity to use later.
Just as the invention of refrigeration changed how people consumed food—allowing them to store it before eating—energy storage can revolutionize how we use energy. It lets us produce clean energy when it’s cheapest, store it, and put it back into the electricity grid when needed. Using storage in conjunction with solar and wind energy helps ensure that power is available even when the sun isn’t shining and the wind isn’t blowing.
In the United States, large-scale storage operations are still relatively rare. But as the amount of wind and solar grows—and the number of coal plants drops—storage will become ever more important for an efficient and clean grid.
Other technologies
Renewable energy isn’t just limited to the sun or wind. Geothermal plants gather heat from the earth to generate steam and produce electricity. Hydroelectric dams exploit the movement of water to turn turbines. New hydrokinetic technologies harness the power of ocean’s currents and tides. And bioenergy—the burning of biomass to generate power—may offer a sustainable use for crops and waste wood.
The key thing tying all of these technologies together is their ability to create electricity with minimal harmful side-effects. The alternatives—fossil fuels—are neither sustainable nor safe.
Switching The World To Renewable Energy Will Cost 62 Trillion, But The Payback Would Take Just 6 Years
Mark Jacobson and his team have published a renewable energy study in which they argue the payback time is just 6 years.
Mark Jacobson and his colleagues at Stanford University have published a new study in the journal Energy Environmental Science that claims 145 of the world’s nations could switch to 100% renewable energy in a few years using renewable energy technologies available today. They recommend the world make the switchover by 2035, but in no event later than 2050. Their goal is to have 80% operating on renewable energy by 2030.
The researchers looked at onshore and offshore wind energy, solar power, solar heat, geothermal electricity and heat, hydroelectricity, and small amounts of tidal and wave electricity. Batteries were the most common electricity storage solution, with the team finding that no batteries with more than four hours of storage were necessary.
“We do not need miracle technologies to solve these problems. By electrifying all energy sectors; producing electricity from clean, renewable sources; creating heat, cold, and hydrogen from such electricity; storing electricity, heat, cold and the hydrogen; expanding transmission; and shifting the time of some electricity use, we can create safe, cheap, and reliable energy everywhere,” Jacobson says. He is a staunch supporter of the Green New Deal.
The researchers say switching to renewable energy would avoid utility grid blackouts and save consumers trillions of dollars. One of the main reasons for that finding is that the combustion-based energy systems most countries rely require a lot of energy just to function. In switching to a clean, renewable energy system, Jacobson states that worldwide energy usage would go down by 56% immediately.
Renewable Energy Efficiency
Those savings are attributable to the efficiency of clean energy over combustion systems, as well as the efficiency of electrified industry. There would no longer be a need to explore for oil, coal, and gas, drill wells or dig new mines, transport oil to refineries, build and maintain pipelines, or truck petroleum products to end users, according to My Modern Met.
Efficiency is something that people who drive electric cars should understand quite well. A gallon of gasoline has the equivalent energy of a 33.7 kWh battery. Many electric cars today have a range of 300 miles or more, which means they can travel that far on the equivalent of 3 gallons of gasoline. A first generation LEAF had a 24 kWh battery, which means it was so efficient, it could go about 80 miles on the equivalent of about.8 gallons of gasoline.
A typical internal combustion engine is 20 to 25% efficient, which means three-quarters of what you pay for is wasted as friction or heat. An electric car is 80 to 95% efficient. In a world that is rapidly overheating, how much longer can we afford to be so profligate with our energy usage? Would you pay 100 for a suit that was worth only 25? Of course not, and yet every time people fill their tanks with gasoline, they are wasting three-quarters of the energy they are paying for.
The problem is similar when we consider thermal generation of electricity. The amount of energy wasted in the process it simply staggering, and yet we continue to generate electricity that way because it is what we are used to and we can’t see another way. Jacobson and company are shining a bright light on an alternate pathway.
Non-Economic Benefits, Too
The study is mostly about economics, but there are significant and quantifiable health benefits to not filling our lungs with air that is mixed with the harmful pollutants that result from combustion. People are Hyper-vigilant about what they put in the bodies today and yet they never give a thought to the crud they breathe and drink and eat that is left over after fossil fuels are burned.
The cost of making the changeover to 100% renewable energy would be a staggering 62 trillion. Wow! That is a ton of money, people. But here’s the thing. Jacobson and his team say the savings from switching the world to 100% renewable energy would be 11 trillion a year. In other words, the initial investment would be paid back in just 6 years! Many people have a hard time distinguishing between an investment and an expense. They tend to see that 62 trillion as an expense and ignore the payback.
Ford is spending 40 billion to transition to making electric cars. Volkswagen, Mercedes, GM, BMW, Hyundai, Honda, Nissan, and Toyota are doing the same. Does anyone think that money is just an expense or that the managers of those companies have not calculated the expected return on their investment down to the fraction of a penny? Why do we continue to view the cost of transferring to renewable energy as an expense and not an investment, one that will pay economic and non-economic benefits for generations?
Wind and sunshine are free. Once the systems to harvest energy from them are completed, the cost of fuel is zero. Yes, those resources will need to be updated, refurbished or replaced over time, just the way utility grids and thermal generating stations need to be as well. But the cost of fuel remains at zero while the price of fossil fuels gyrates radically over time.
There’s one other aspect of renewable energy that you can’t put a price on but it’s extremely valuable nonetheless — energy security. Nations that generate their own electricity don’t need to be at the mercy of lunatics and despots who can decide at any time to cut off the supply of oil, or unnatural gas, or coal. How much is that worth? It may be hard to answer that question, but it is clearly not nothing. The people of Europe are facing a long cold winter because the supply of cheap methane from Russia has ended abruptly. How much would energy security be worth to them?
The Takeaway
In the conclusion to their study, Jacobson and his research colleagues say, “Transitioning to 100% [renewable energy] in 145 countries decreases energy requirements and annual private and social costs while creating about 28.4 million more long term, full time jobs than lost. A 100% [renewable energy] economy uses only about 0.53% of the 145 country land area, with 0.17% for footprint and 0.36% for spacing.”
People may quibble over some of the timing and access to the raw and manufactured materials needed to complete a changeover to 100% renewable energy. They may worry that there is not enough political will to make this happen. Those are valid concerns. But what the Stanford team is doing is setting a target. As Forrest Gump said, “If you don’t know where you are going, you’re not likely to end up there.”
It’s easy to say the task is too hard or too expensive or pushes too far, too fast. Those might be concerns for ordinary challenges. But when the objective is preserving the Earth as a sustainable place where human beings can live, making bold plans is really the least we can do.
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Top 10: Most Popular Renewable Energy Sources
Renewable energy can be classified as originating from a natural source that replenishes itself. Scientists have stated that to avoid the worst impacts of climate change, emissions need to be reduced by almost half in the next ten years. It is no surprise that renewable energy has been described as a ‘solution’ to avoid the worst impacts of climate change, as well as ensuring that humanity relies less on fossil fuels.
The UN has suggested that 30 million jobs can be created as a result of renewable energy sources. Energy Magazine is therefore considering 10 of the most popular current sources for renewable energy.
: Biomass
Biomass is generated from burning wood, plants and other organic matter, such as manure or household waste. According to the Energy Saving Trust, it has the potential to use considerably less carbon dioxide (net carbon emissions) than fossil fuels, and can be considered renewable if the plants are being replaced.
In addition, biomass is less expensive than fossil fuels and can be used for fuels, power, and products that would otherwise be made from fossil fuels. Technologies can be created from biomass, including biofuels, conversion into heat and electricity and chemicals for making plastics.
Ethanol fuel
Ethanol fuel is most often used as a motor fuel as an alternative to petrol or gasoline. It is the same as the ethyl alcohol that you find in alcoholic drinks and often obtained from corn or grains. It has been determined to reduce emissions and so it can be blended with gasoline to increase the octane level of the fuel.
With plenty of governments now prioritising the reduction of fuel emissions (London’s ULEZ zone expansion this year for example), the use of ethanol fuels has greatly increased over the past decade.
Hydropower
Also sustainable, is Hydropower (also known as water power), which is the use of falling or fast-running water to make electricity or to generate power. This is conducted by converting the kinetic energy of the water to produce the power, which is often by building a dam to control the flow of a river or large body of water.
The benefits of this power is that it is a clean source of energy and it does not rely on international fuel sources. It also allows for greater flood control and clean drinking water, whilst being a very affordable, low-cost type of energy.
Hydroelectric
Much like hydropower, this type of renewable power uses moving water to generate electricity. It is the most widely used renewable energy source worldwide. Most have a reservoir of water, which gains potential energy before it spills over the top of a dam or flows down a hill. This is then used to generate electricity for customers.
These plants produce no direct waste and typically emit much less greenhouse gas than fossil fuel-powered energy plants. However, with some structures, there has been disruption caused to the environment around them.
Geothermal
Geothermal energy is heat from within the earth and is continually produced. Electricity generated from the ground is currently used in 26 countries, with geothermal heating being used in 70 countries. The main advantage of this is that it is always readily available, so there is less demand to actually generate power.
One of the countries that is perhaps most well-known for utilising geothermal power is Iceland, with 30% using geothermal power because of the very active geology within the country. Geothermal energy now heats more than 90% of the houses in Iceland, with the country operating with 100% renewable energy.
Marine/Ocean
In generating power in the ocean, the term marine power includes wave power (surface waves) and tidal power (kinetic energy of large bodies of water). This type of power is harnessed from the natural power of the ocean and the technologies involved can include turbines and paddles.
According to Dr. Abdus Samad and R. Suchithra, energy can be extracted from the sea in several ways. These methods include salinity (salt concentration), temperate, waves and ocean currents. Ultimately, this method of harnessing energy has huge potential as source of renewable energy.
Tidal
specific to water levels, tidal power or tidal energy is obtained by converting energy from tides into useful forms of power, mainly electricity. Although not yet widely used, tidal energy has the potential for future electricity generation. Tidal energy could be used instead of burning coal and oil that contribute to global warming, as well as transporting and capturing energy by ocean waves.
National Geographic has suggested that tides can be more predictable than alternative forms of renewable energy, like wind and solar power. This is because water is more dense and therefore more powerful, ultimately creating a more reliable energy source.
Photovoltaic solar energy
Photovoltaic solar energy is obtained by converting sunlight into electricity using a technology based on the photoelectric effect. The system converts radiation from the sun (sunlight) into usable electricity. Most commonly recognised in solar panels, the panel consists of cells made from layers of semiconducting material. When light shines on it, a flow of electricity is created as a result.
Whilst more electricity is generated on sunny days, the cells do not need direct sunlight to work. It can often be used as standalone power, as they can provide electricity to parking metres, radio transmitters and emergency phones, for example.
Solar thermal power
Slightly similar, solar thermal power systems use concentrated solar energy to generate thermal energy for use. This is done by heat-transfer circulating to produce steam, which is then converted into mechanical energy to produce electricity. Currently, it is used in industry and commercial sectors, as well as residential areas.
The main source of heat generation is through roof mounted solar panels which are used in conjunction with a heat source, such as a boiler, collector or immersion heater. The solar source will collect sunlight, before being pumped to the heat source and being heated inside. It is a common misconception that this type of power cannot be used in the UK, as any type of light from the sun is suitable.
Most commonly recognised in solar panels, the panel consists of cells made from layers of semiconducting material.
Wind. onshore and offshore
Wind power is used both onshore and offshore around the world and is well-known for its small impact on the environment. Harnessed by wind turbines, these can be placed in groups in either the ground or offshore in the ocean. In 2021, wind generated 6.6% of global electricity, which was up from 3.5% in 2015 when the Paris Agreement was signed. There are still calls for this amount to increase, however.
Some disadvantages of wind power are that often, suitable sites for wind power are often in remote locations, as well as affecting the landscape on account of being very visible and producing noise. However, it is considered to be a very sustainable type of power, with the turbines themselves not producing any emissions.