Wind turbines and solar panels are an increasingly common sight. But why? What are the benefits of renewable energies—and how do they improve our health, environment, and economy?
This page explores the many positive impacts of clean energy, including the benefits of wind, solar, geothermal, hydroelectric, and biomass. For more information on their negative impacts—including effective solutions to avoid, minimize, or mitigate—see our page on The Environmental Impacts of Renewable Energy Technologies.
Less global warming
Human activity is overloading our atmosphere with carbon dioxide and other global warming emissions. These gases act like a blanket, trapping heat. The result is a web of significant and harmful impacts, from stronger, more frequent storms, to drought, sea level rise, and extinction.
In the United States, about 29 percent of global warming emissions come from our electricity sector. Most of those emissions come from fossil fuels like coal and natural gas [1, 2].
What is CO2e?
Carbon dioxide (CO2) is the most prevalent greenhouse gas, but other air pollutants—such as methane—also cause global warming. Different energy sources produce different amounts of these pollutants. To make comparisons easier, we use a carbon dioxide equivalent, or CO2e—the amount of carbon dioxide required to produce an equivalent amount of warming.
In contrast, most renewable energy sources produce little to no global warming emissions. Even when including “life cycle” emissions of clean energy (ie, the emissions from each stage of a technology’s life—manufacturing, installation, operation, decommissioning), the global warming emissions associated with renewable energy are minimal .
The comparison becomes clear when you look at the numbers. Burning natural gas for electricity releases between 0.6 and 2 pounds of carbon dioxide equivalent per kilowatt-hour (CO2E/kWh); coal emits between 1.4 and 3.6 pounds of CO2E/kWh. Wind, on the other hand, is responsible for only 0.02 to 0.04 pounds of CO2E/kWh on a life-cycle basis; solar 0.07 to 0.2; geothermal 0.1 to 0.2; and hydroelectric between 0.1 and 0.5.
Renewable electricity generation from biomass can have a wide range of global warming emissions depending on the resource and whether or not it is sustainably sourced and harvested.
Increasing the supply of renewable energy would allow us to replace carbon-intensive energy sources and significantly reduce US global warming emissions.
For example, a 2009 UCS analysis found that a 25 percent by 2025 national renewable electricity standard would lower power plant CO2 emissions 277 million metric tons annually by 2025—the equivalent of the annual output from 70 typical (600 MW) new coal plants .
In addition, a ground-breaking study by the US Department of Energy's National Renewable Energy Laboratory (NREL) explored the feasibility of generating 80 percent of the country’s electricity from renewable sources by 2050. They found that renewable energy could help reduce the electricity sector’s emissions by approximately 81 percent .
Improved public health
The air and water pollution emitted by coal and natural gas plants is linked with breathing problems, neurological damage, heart attacks, cancer, premature death, and a host of other serious problems. The pollution affects everyone: one Harvard University study estimated the life cycle costs and public health effects of coal to be an estimated $74.6 billion every year. That’s equivalent to 4.36 cents per kilowatt-hour of electricity produced—about one-third of the average electricity rate for a typical US home .
Most of these negative health impacts come from air and water pollution that clean energy technologies simply don’t produce. Wind, solar, and hydroelectric systems generate electricity with no associated air pollution emissions. Geothermal and biomass systems emit some air pollutants, though total air emissions are generally much lower than those of coal- and natural gas-fired power plants.
In addition, wind and solar energy require essentially no water to operate and thus do not pollute water resources or strain supplies by competing with agriculture, drinking water, or other important water needs. In contrast, fossil fuels can have a significant impact on water resources: both coal mining and natural gas drilling can pollute sources of drinking water, and all thermal power plants, including those powered by coal, gas, and oil, withdraw and consume water for cooling.
Biomass and geothermal power plants, like coal- and natural gas-fired power plants, may require water for cooling. Hydroelectric power plants can disrupt river ecosystems both upstream and downstream from the dam. However, NREL's 80-percent-by-2050 renewable energy study, which included biomass and geothermal, found that total water consumption and withdrawal would decrease significantly in a future with high renewables .
Strong winds, sunny skies, abundant plant matter, heat from the earth, and fast-moving water can each provide a vast and constantly replenished supply of energy. A relatively small fraction of US electricity currently comes from these sources, but that could change: studies have repeatedly shown that renewable energy can provide a significant share of future electricity needs, even after accounting for potential constraints .
In fact, a major government-sponsored study found that clean energy could contribute somewhere between three and 80 times its 2013 levels, depending on assumptions . And the previously mentioned NREL study found that renewable energy could comfortably provide up to 80 percent of US electricity by 2050.
Jobs and other economic benefits
Compared with fossil fuel technologies, which are typically mechanized and capital intensive, the renewable energy industry is more labor intensive. Solar panels need humans to install them; wind farms need technicians for maintenance.
This means that, on average, more jobs are created for each unit of electricity generated from renewable sources than from fossil fuels.
Renewable energy already supports thousands of jobs in the United States. In 2016, the wind energy industry directly employed over 100,000 full-time-equivalent employees in a variety of capacities, including manufacturing, project development, construction and turbine installation, operations and maintenance, transportation and logistics, and financial, legal, and consulting services . More than 500 factories in the United States manufacture parts for wind turbines, and wind power project installations in 2016 alone represented $13.0 billion in investments .
Other renewable energy technologies employ even more workers. In 2016, the solar industry employed more than 260,000 people, including jobs in solar installation, manufacturing, and sales, a 25% increase over 2015 . The hydroelectric power industry employed approximately 66,000 people in 2017 ; the geothermal industry employed 5,800 people .
Increased support for renewable energy could create even more jobs. The 2009 Union of Concerned Scientists study of a 25-percent-by-2025 renewable energy standard found that such a policy would create more than three times as many jobs (more than 200,000) as producing an equivalent amount of electricity from fossil fuels .
In contrast, the entire coal industry employed 160,000 people in 2016 .
In addition to the jobs directly created in the renewable energy industry, growth in clean energy can create positive economic “ripple” effects. For example, industries in the renewable energy supply chain will benefit, and unrelated local businesses will benefit from increased household and business incomes .
Local governments also benefit from clean energy, most often in the form of property and income taxes and other payments from renewable energy project owners. Owners of the land on which wind projects are built often receive lease payments ranging from $3,000 to $6,000 per megawatt of installed capacity, as well as payments for power line easements and road rights-of-way. They may also earn royalties based on the project’s annual revenues. Farmers and rural landowners can generate new sources of supplemental income by producing feedstocks for biomass power facilities.
UCS analysis found that a 25-by-2025 national renewable electricity standard would stimulate $263.4 billion in new capital investment for renewable energy technologies, $13.5 billion in new landowner income from? biomass production and/or wind land lease payments, and $11.5 billion in new property tax revenue for local communities .
Stable energy prices
Renewable energy is providing affordable electricity across the country right now, and can help stabilize energy prices in the future.
Although renewable facilities require upfront investments to build, they can then operate at very low cost (for most clean energy technologies, the “fuel” is free). As a result, renewable energy prices can be very stable over time.
Moreover, the costs of renewable energy technologies have declined steadily, and are projected to drop even more. For example, the average price to install solar dropped more than 70 percent between 2010 and 2017 . The cost of generating electricity from wind dropped 66 percent between 2009 and 2016 . Costs will likely decline even further as markets mature and companies increasingly take advantage of economies of scale.
In contrast, fossil fuel prices can vary dramatically and are prone to substantial price swings. For example, there was a rapid increase in US coal prices due to rising global demand before 2008, then a rapid fall after 2008 when global demands declined . Likewise, natural gas prices have fluctuated greatly since 2000 .
Using more renewable energy can lower the prices of and demand for natural gas and coal by increasing competition and diversifying our energy supplies. And an increased reliance on renewable energy can help protect consumers when fossil fuel prices spike.
Reliability and resilience
Wind and solar are less prone to large-scale failure because they are distributed and modular. Distributed systems are spread out over a large geographical area, so a severe weather event in one location will not cut off power to an entire region. Modular systems are composed of numerous individual wind turbines or solar arrays. Even if some of the equipment in the system is damaged, the rest can typically continue to operate.
For example, Hurricane Sandy damaged fossil fuel-dominated electric generation and distribution systems in New York and New Jersey and left millions of people without power. In contrast, renewable energy projects in the Northeast weathered Hurricane Sandy with minimal damage or disruption .
Water scarcity is another risk for non-renewable power plants. Coal, nuclear, and many natural gas plants depend on having sufficient water for cooling, which means that severe droughts and heat waves can put electricity generation at risk. Wind and solar photovoltaic systems do not require water to generate electricity and can operate reliably in conditions that may otherwise require closing a fossil fuel-powered plant. (For more information, see How it Works: Water for Electricity.)
The risk of disruptive events will also increase in the future as droughts, heat waves, more intense storms, and increasingly severe wildfires become more frequent due to global warming—increasing the need for resilient, clean technologies.
 Environmental Protection Agency. 2017. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2015.
 Energy Information Agency (EIA). 2017. How much of the U.S. carbon dioxide emissions are associated with electricity generation?
 Intergovernmental Panel on Climate Change (IPCC). 2011. IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation. Prepared by Working Group III of the Intergovernmental Panel on Climate Change [O. Edenhofer, R. Pichs-Madruga, Y. Sokona, K. Seyboth, P. Matschoss, S. Kadner, T. Zwickel, P. Eickemeier, G. Hansen, S. Schlömer, C. von Stechow (eds)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1075 pp. (Chapter 9).
 Union of Concerned Scientists (UCS). 2009. Clean Power Green Jobs.
 National Renewable Energy Laboratory (NREL). 2012. Renewable Electricity Futures Study. Volume 1, pg. 210.
 Epstein, P.R.,J. J. Buonocore, K. Eckerle, M. Hendryx, B. M. Stout III, R. Heinberg, R. W. Clapp, B. May, N. L. Reinhart, M. M. Ahern, S. K. Doshi, and L. Glustrom. 2011. Full cost accounting for the life cycle of coal in “Ecological Economics Reviews.” Ann. N.Y. Acad. Sci. 1219: 73–98.
 Renewable Electricity Futures Study. 2012.
 NREL. 2016. Estimating Renewable Energy Economic Potential in the United States: Methodology and Initial Results.
 Renewable Electricity Futures Study. 2012.
IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation. Prepared by Working Group III of the Intergovernmental Panel on Climate Change. 2011.
UCS. 2009. Climate 2030: A national blueprint for a clean energy economy.
 American Wind Energy Association (AWEA). 2017. AWEA U.S. Wind Industry Annual Market Report: Year Ending 2016. Washington, D.C.: American Wind Energy Association.
 Wiser, Ryan, and Mark Bolinger. 2017. 2016 Wind Technologies Market Report. U.S. Department of Energy.
 The Solar Foundation. 2017. National Solar Jobs Census 2016.
 Navigant Consulting. 2009. Job Creation Opportunities in Hydropower.
 Geothermal Energy Association. 2010. Green Jobs through Geothermal Energy.
 UCS. 2009. Clean Power Green Jobs.
 Environmental Protection Agency. 2010. Assessing the Multiple Benefits of Clean Energy: A Resource for States. Chapter 5.
 UCS. 2009. Clean Power Green Jobs.
 Deyette, J., and B. Freese. 2010. Burning coal, burning cash: Ranking the states that import the most coal. Cambridge, MA: Union of Concerned Scientists.
 SEIA. 2017. Solar Market Insight Report 2017 Q2.
 AWEA. 2017. AWEA U.S. Wind Industry Annual Market Report: Year Ending 2016. Washington, D.C.: American Wind Energy Association.
 UCS. 2009. Clean Power Green Jobs.
 UCS. 2011. A Risky Proposition: The financial hazards of new investments in coal plants.
 EIA. 2013. U.S. Natural Gas Wellhead Price.
 Unger, David J. 2012. Are renewables stormproof? Hurricane Sandy tests solar, wind. The Christian Science Monitor. November 19.
 Department of Energy. 2017 U.S. Energy and Employment Report
Different sources of energy produce different amounts of heat-trapping gases. As shown in this chart, renewable energies tend to have much lower emissions than other sources, such as natural gas or coal.
Source: IPCC, 2011 Special Report on Renewable Energy Sources and Climate Change Mitigation (Chapter 9).
Photo: Diliff/Wikimedia Commons
Two energy workers installing solar panels.
Photo: Dennis Schroeder / NREL
Energy’s Future Today
The sun is the ultimate source of energy for our planet. Its energy is found in fossil fuels as well as all living things. Harnessing its energy holds great promise for the world’s energy needs, and it will be heavily called upon as fossil fuels are depleted.
There is a great deal of information and enthusiasm today about the development and increased production of our global energy needs from alternative energy sources. Solar energy, wind power and moving water are all traditional sources of alternative energy that are making progress. The enthusiasm everyone shares for these developments has in many ways created a sense of complacency that our future energy demands will easily be met.
Alternative energy is an interesting concept when you think about it. In our global society, it simply means energy that is produced from sources other than our primary energy supply: fossil fuels. Coal, oil and natural gas are the three kinds of fossil fuels that we have mostly depended on for our energy needs, from home heating and electricity to fuel for our automobiles and mass transportation.
The problem is fossil fuels are non-renewable. They are limited in supply and will one day be depleted. There is no escaping this conclusion. Fossil fuels formed from plants and animals that lived hundreds of millions of years ago and became buried way underneath the Earth’s surface where their remains collectively transformed into the combustible materials we use for fuel.
In fact, the earliest known fossil fuel deposits are from the Cambrian Period about 500 million years ago, way before the dinosaurs emerged onto the scene. This is when most of the major groups of animals first appeared on Earth. The later fossil fuels — which provide more substandard fuels like peat or lignite coal (soft coal) — began forming as late as five million years ago in the Pliocene Period. At our rate of consumption, these fuels cannot occur fast enough to meet our current or future energy demands.
Despite the promise of alternative energy sources — more appropriately called renewable energy, collectively they provide only about 7 percent of the world’s energy needs (Source: Energy Information Agency). This means that fossil fuels, along with nuclear energy — a controversial, non-renewable energy source — are supplying 93 percent of the world’s energy resources.
Dams are a major source of hydroelectric energy, such as the Hoover Dam on the Colorado River (pictured). While they collect the vast raw energy provided by water currents, they also create environmental hazards such as silt buildup. They are also significant barriers to fish, such as the salmon of the Pacific Northwest, which must migrate in order for the species to survive. The Hoover Dam is a major source of energy for the southwestern US. (Photo: US Bureau of Reclamation)
Nuclear energy, which is primarily generated by splitting atoms, only provides 6 percent of the world’s energy supplies. Still, nuclear energy is not likely to be a major source of world energy consumption because of public pressure and the relative dangers associated with unleashing the power of the atom. Yet, governments such as the United States see its vast potential and are placing pressure on the further exploitation of nuclear energy.
The total world energy demand is for about 400 quadrillion British Thermal Units — or BTUs — each year (Source: US Department of Energy). That’s 400,000,000,000,000,000 BTUs! A BTU is roughly equal to the energy and heat generated by a match. Oil, coal and natural gas supply nearly 88 percent of the world’s energy needs, or about 350 quadrillion BTUs. Of this amount, oil is king, providing about 41 percent of the world’s total energy supplies, or about 164 quadrillion BTUs. Coal provides 24 percent of the world’s energy, or 96 quadrillion BTUs, and natural gas provides the remaining 22 percent, or 88 quadrillion BTUs.
It’s not so much that we mine fossil fuels for our consumption any more than it is to mine salt or tap water supplies way underground. The problems occur when we destroy ecosystems while mining it and while using it. Certainly, if there were a way that fossil fuels can be mined and used in ways that do not harm our ecology, then everything will be okay… in a perfect world. What makes our world perfect is that, it really isn’t perfect according to definition. It is natural, with all things interdependent on each other to live, grow and produce. Fossil fuel mining and oil production can and has caused irreparable damage to our environment.
The Fossil Fuel Dilemma
Fossil fuels exist, and they provide a valuable service. It’s not so much that we use fossil fuels for energy that is problematic, but it’s the side effects of using them that causes all of the problems. Burning fossil fuels creates carbon dioxide, the number one greenhouse gas contributing to global warming. Combustion of these fossil fuels is considered to be the largest contributing factor to the release of greenhouse gases into the atmosphere. In the 20th century, the average temperature of Earth rose 1 degree Fahrenheit (1°F). This period saw the most prolific population growth and industrial development — which was and remains totally dependent on the use of energy — in Earth’s history.
The impact of global warming on the environment is extensive and affects many areas. In the Arctic and Antarctica, warmer temperatures are causing the ice to melt which will increase sea level and change the composition of the surrounding sea water. Rising sea levels alone can impede processes ranging from settlement, agriculture and fishing both commercially and recreationally. Air pollution is also a direct result of the use of fossil fuels, resulting in smog and the degradation of human health and plant growth.
But there are also the great dangers posed to natural ecosystems that result from collecting fossil fuels, particularly coal and oil. Oil spills have devastated ecosystems and coal mining has stripped lands of their vitality. These among others are the primary reasons to discontinue the pursuit to tap the vast oil reserves in the Arctic National Wildlife Refuge (ANWR).
Oil fossil fuels come from marine plants and animals and are found only underneath the ocean or under land that was covered by the oceans millions of years ago. This oil rig is located offshore in the Arabian Gulf. (Photo: Saudi Arabian Embassy – London)
The oil, coal and natural gas companies know these are serious problems. But until our renewable energy sources become more viable as major energy providers, the only alternative for our global population is for these companies to continue tapping into the fossil fuel reserves to meet our energy needs. And you can pretty much count on these companies being there providing energy from renewable sources when the fossil fuels are depleted. Many oil companies, for example, are involved in the development of more reliable renewable energy technologies. For example, British Petroleum Company, today known as BP, has become one of the world’s leading providers of solar energy through its BP Solar division, a business that they are planning on eclipsing their oil production business in the near future.
Future Supplies for Future Energy
Just how limited are our fossil fuel reserves? Some estimates say our fossil fuel reserves will be depleted within 50 years, while others say it will be 100-120 years. The fact is that neither one of these projections is very appealing for a global community that is so heavily dependent on fossil fuels to meet basic human needs. The bottom line: We are going to run out of fossil fuels for energy and we have no choice but to prepare for the new age of energy production since, most certainly, human demands for energy will not decrease.
Modern windmills have become very efficient at transferring the energy of wind to electricity. Wind power is an important part of the overall renewable energy sources for the future. (Photo: CORE)
Nobody really knows when the last drop of oil, lump of coal or cubic foot of natural gas will be collected from the Earth. All of it will depend on how well we manage our energy demands along with how well we can develop and use renewable energy sources.
And here is one very important factor: population growth. As the population grows upwards towards nine billion people over the next 50 years, the world’s energy demands will increase proportionately. Not only will it be important for renewable energy to keep up with the increasing population growth, but it must outpace not only these demands but begin replacing fossil fuel energy production if we are to meet future energy needs.
By the year 2020, world energy consumption is projected to increase by 50 percent, or an additional 207 quadrillion BTUs. If the global consumption of renewable energy sources remains constant, the world’s available fossil fuel reserves will be consumed in 104 years or early in the 22nd century.(Source: US Department of Energy) Clearly, renewable energy resources will play an increasingly vital role in the power generation mix over the next century.
The Ultimate Energy Sources as the Underdogs
Solar energy is having the most immediate impact on home energy needs, and is expected to provide the energy needs for one billion people by the middle of this century. Homes can be fitted with solar panels, such as the ones pictured above. (Photo: Maui Green Energy)
Sun, wind and water are perfect energy sources…depending on where you are. They are non-polluting, renewable and efficient. They are simple: all you need is sunlight, running water and/or wind. Not only do the use of renewable energy sources help reduce global carbon dioxide emissions, but they also add some much-needed flexibility to the energy resource mix by decreasing our dependence on limited reserves of fossil fuels.
Essentially, these renewable energy sources create their own energy. The object is to capture and harness their mechanical power and convert it to electricity in the most effective and productive manner possible. There’s more than enough renewable energy sources to supply all of the world’s energy needs forever; however, the challenge is to develop the capability to effectively and economically capture, store and use the energy when needed.
Take solar energy for example. The ultimate source of energy is the sun. Its energy is found in all things, including fossil fuels. Plants depend on the sun to make food, animals eat the plants, and both ended up becoming the key ingredients for fossil fuels. Without the sun, nothing on this planet would exist.
The sun also provides enough energy that can be stored for use long after the sun sets and even during extended cloudy periods. But making it available is much easier said than done. It would be cost prohibitive to make solar energy mainstream for major world consumption in the near future. The technology is pretty much ready for many business and consumer applications, but it would be way too expensive to replace the current energy infrastructure used for fossil fuel energy. Still, according to the European Photovoltaic Industry Association, solar power could provide energy for more than one billion people by 2020 and 26 percent of global energy needs by 2040.
Wind and hydroelectric power, which have been used effectively for generations, are also rapidly growing energy markets. The principle behind both is that the force of the wind and water currents are passed through turbines which convert their energy into electricity. Commercial wind energy is usually collected by wind “farms” essentially consisting of hundreds of wind turbines (windmills) spread over large plots of land.
But hydroelectric power is harnessed in several different methods. The most popular is through dams, such as the Hoover Dam on the Colorado River. Another form of hydroelectric energy is tidal power. In use since the early 1900s, tidal power stations collect the energy created by the rise and fall of the tides to convert to electricity.
Biomass energy, or energy from burning plants and other organic matter, is one of man’s earliest sources of energy. Wood was once the main source of power for heat, and it still is in many developing countries. Most people in developed countries use wood only for aesthetic purposes or secondary heating, limited mainly to fireplaces and decorative woodstoves. Roughly one to two billion people in the developing nations still use wood as their primary source of heat. It is this group that is seen being among the first to convert to solar heating and energy because there is no other existing infrastructure to hinder its development.
Perhaps the best solution to our growing energy challenges comes from The Union of Concerned Scientists: “No single solution can meet our society’s future energy needs. The solution instead will come from a family of diverse energy technologies that share a common thread — they do not deplete our natural resources or destroy our environment.”
Did You Know?
Wind energy is actually a form of solar energy. Wind is formed from the heating and cooling of the atmosphere, which causes air and air layers to rise and fall and move over each other. This movement results in wind currents.