Wind Power and its Impact on the Environment

With the world becoming more and more interested in renewable energy sources, wind power too has gotten more and more attention as an extremely viable source for electricity generation.  In fact, in 2013, Spain reported that wind farms produced more electricity than any other form of energy production, including coal and nuclear power stations.  This shows just how important wind power is becoming on a world stage.

To harness the wind’s power, large wind turbines are erected.  These can be as tall as a twenty story building with 200 ft. blades. To create electricity, the wind spins the blades of the turbine.  This, in turn spins a shaft that is connected to an electrical generator.  In order to maximize energy production, turbines are often clumped together, sometimes hundreds in a row in a wind farm.  These farms attempt to place the turbines in windy spots, such as on ridges or off shore, and space them out in just the right way, again to maximize energy production.

Fenton Wind Farm in Minnesota

Wind power is also growing in popularity because it is an extremely inexpensive form of energy.  Wind is free, so, once the turbines are up and running there is very little cost to run these farms.  Mass production of the wind turbines themselves has reduced the costs as well as government tax breaks and incentives designed to bolster the wind-energy industry.

Wind turbines also have a net energy gain, meaning that eventually, they produce more energy than was consumed during their construction.  In fact, during a turbine’s lifetime, it produces several times more energy than was required to build it, making turbines both economically and energetically efficient.  Furthermore, the energy return on investments, or the EROI is quite high.  For wind turbines, this number (calculated by dividing the total energy generated by the energy required to build the turbine), ranges from 5 to 35 according to a meta study.  This study examined data from 1997 to 2007.  So, the lower EROI can be attributed to older, out of date technology.  Now, the most common wind turbines have an EROI of 16.  This is important because in developed countries, 7 is considered the minimum EROI.

So, wind turbines seem like the perfect system.  They take free wind and turn it into electricity at a very low cost.  But what are the effects of these structures on the surrounding environment?  Is wind power too good to be true?

First, let’s consider the variability of wind itself.  Wind turbines can only produce electricity if there is wind to move the blades.  So, in order to prevent the entire system or the electrical grid from shutting down when the weather does not cooperate, many wind farms employ a buffering system.  Meaning that in order to continue energy production, many farms switch energy generation reserves.   These are systems that are able to adapt to accommodate changes in energy supply and demand.  Ideally, these are powered by a reliable and clean energy source, such as hydroelectric energy (energy produced by the kinetic energy of flowing water).  But, in the United States, most of these reserves are actually powered by natural gas.  So in reality, wind power in the U.S. is not entirely renewable because it is a hybrid of wind and this natural gas.  Therefore, the environmental impact is not as minor as it would appear.  Yes, the wind power does offset some the CO2 emissions created by the natural gas power plant.  In fact,  scientists believe that on average, the addition of only 3 more MW of wind energy to the U.S. electric grid would decrease the emissions of CO2 from fossil power plants by 1,200 pounds per hour.  But, even so, they are not replacing these emissions.  Since wind is only available about 30% of the time, in reality, most of our “wind energy” actually comes from natural gas, a non renewable resource.

Again, it is possible to employ the buffering system without using fossil fuels.  A great example of a country that makes it’s wind power work without using fossil fuels is Denmark, one of the most wind-energy-intensive countries world wide.  Instead of buffering their wind energy against fossil fuels like the U.S., they partner with nearby Sweden and Norway and take advantage of their hydroelectric energy.  So, when wind is blowing, Denmark exports electricity to Sweden, who can then store more water in their dams.  Then, when the wind is not blowing, Sweden can release the stored water and export electricity back to Denmark.  This symbiotic relationship is relatively eco-friendly because it uses all natural and renewable resources.  However, it is only viable because of the unique geographic features and locations of the countries.

Another aspect to consider when examining environmental impact is harmful emissions which create air pollution.  While in operation, wind turbines do not release C02 emissions, which is one reason why wind power is so popular.

The Vattenhall utility company studied greenhouse emissions for various forms of energy. Clearly, wind energy has some of the drastically lowest carbon emissions
The Vattenhall utility company studied greenhouse emissions for various forms of energy. Clearly, wind energy has some of the drastically lowest carbon emissions

However, one must examine the wind turbines from construction to dismantling, or the entire life cycle, in order to get a full picture of the environmental impact.  According to the life cycle assessments of wind energy, turbines do contribute harmful emissions into the atmosphere, particularly during the construction phase.  However, most of the emissions are nearly negligible, especially compared to more conventional methods using fossil fuels such as natural gas.  Unfortunately, wind farms do emit more particulate matter per unit of energy created (kWh) than do fossil fuel plants.  This particulate matter refers to any tiny liquid or solid that because of the wind turbines is suspended in Earth’s atmosphere such as natural or cement dust.

Furthermore, in 2006, a European study examined externality costs, or costs of external pollution.  Externality is an economic term that refers to the cost to a person who didn’t choose to receive that cost.  In our case, the externality cost would refer to the communities near these various power plants.  This study found that for wind power, externality costs were 0.09 – 0.12c€/kW.  This is an extremely low cost, especially compared the 1.6-5.8 c€/kWh externality costs of fossil fuels.  To put these numbers into perspective, energy costs in Europe are approximately 10 c€/kWh.  So, the externality costs of wind power are a tiny fraction of total energy costs, showing that wind power does not cause a significant amount of pollution.

One must also examine the impact on wildlife to form a full picture of the impact of wind power on the environment.  Wind turbines pose a huge threat to flying creatures such as bats and birds.  One study examined impact of wind turbines on bird deaths and estimated that wind turbines in the U.S. kill an average number of 234,000 birds annually.  However, there are a plethora of causes for bird death in the United States.  Compared to fossil fuel plants which are responsible for approximately 14 million bird deaths or even buildings and windows which are responsible for a shocking 365 – 988 million, wind turbines, again have very little relative impact on the lives of the birds.  That being said, wind farm can implement mitigation factors, especially to help conserve at risk species.  The Peñascal Wind Power Project in Texas has just such a practice in place.  It’s wind farm is located directly along a major migration route for birds.  So, the farm has implemented an avian radar to detect approaching birds.  If the birds appear to be in danger of running into the blades, then the farm shuts down the turbines and allows the birds to pass.  So, although wind farms can be harmful to birds, there are ways in which to minimize these harmful effects.  In fact, the Royal Society for the Protection of Birds issued a statement saying that “climate change poses the single greatest long-term threat to birds and other wildlife” as well as saying that “the available evidence suggests that appropriately positioned wind farms do not pose a significant hazard for birds.”

As for bats, they face a similar problem with colliding with the turbines.  However, the situation is even more grave than that of birds.   One study examined this issue and found that 600,000 to 900,000 bats were killed by turbines each year.  This is because bats, in particular, the Hoary bat uses trees as a landmark.  The male hoary bat will locate the tallest tree and then circle it searching for a mate.  However, the bats cannot distinguish between trees and the turbines and may run into the blades.  Like with birds, biologists and conservationists recommend preventative measures.  Wind turbines normally stay idle when there is no wind and turn on when the air reaches a certain speed threshold.  Right now this threshold tends to be around 3.5 meters per second.  However, bats don’t like to fly when it is overly windy.  So, if wind farms up their threshold, especially during migration seasons, it could reduce bat fatalities by a staggering 43-93%.  So, as long as wind farm take preventative measures such as these, there is no reason that wind power should negatively hurt bats in a significant way.

Overall, wind power is an extremely good non option for clean, renewable energy production.  Of course no system is perfect.  Wind energy is susceptible to changes in weather so it is not reliable at all times.  It also does emit some particulate matter, which contributes to air pollution.  Finally, wind turbines do pose a threat to wildlife in the area, especially birds and bats.  However, wind farms are already taking steps to protect these creatures.  Thus, most conservationists agree that wind power “reduces carbon emissions, pollution, provides jobs and economic growth, so [ despite the negatives, they] see it as a net positive.”  For these reasons, wind energy has the potential to become one of the most crucial forms of energy world wide.

Nuclear Waste Management

Nuclear Waste Management: Finding Solutions for a Sustainable Future

In order to understand where nuclear waste comes from, one must understand what nuclear energy is.  There are two nuclear processes that can create energy.  The first is fusion, or combining atoms to produce energy and a new, heavier atom.  This process can create huge amounts of energy with fairly low amounts of radioactive bi-products.  However, this type of nuclear reaction is not currently commercially feasible and only occurs naturally on places such as the sun.

The second process of extracting nuclear energy is through the process of fusion, or the splitting of atoms, namely uranium and plutonium.  Nuclear power plants use the heat that is released as part of this reaction and turn that thermal energy into electricity.  Of course, no reaction is one hundred percent efficient, and a byproduct of nuclear reactions is nuclear waste.  Nuclear waste is extremely radioactive and therefore dangerous.  It is so toxic, that if a person were to stand near the waste after it came out of the reactor, even if just for a few seconds, they would die of acute radiation sickness.

Unfortunately, this fear of nuclear waste has led to a stigma against nuclear energy.  Many people associate nuclear energy with tragedies such as Chernobyl or with weapons of mass destruction.  In reality, nuclear energy is quite the opposite.  According to world-nuclear.org , nuclear waste management is “neither particularly hazardous nor hard to manage relative to other toxic industrial wastes.”  In other words,  there are other common forms of waste that come from places such as coal and electrical power plants that are more threatening to the public than nuclear waste.  For instance, one study found that people who lived near coal powered plants had approximately 18 millirems of radiation in their bones as opposed to those people living near nuclear power plants who only had 3-6 millirems.  Additionally, for the food grown, radiation doses were between 50-200% higher in the food grown near the coal than the nuclear power plant.

Furthermore, unlike other types of waste, the potency of nuclear waste decreases over time.  The particles in radioactive waste all have a half life, which is one half the time it takes for the radioactive substance to decay to lose it’s radioactivity.  For instance, once radioactive substance, Uranium-238 has a half life of approximately 4.5 billion years.  This means, that in 4.5 billion years, 50% of Uranium-238’s atoms will have decayed to nonradioactive decay products.  Then, after 9 billion years, 75 % of the atoms will have decayed, and so on and so forth.   So, eventually, all nuclear waste becomes harmless.  However, as we can see simply with the example of Uranium-238, depending on the type of nuclear waste, this can take a very long time.  But, some nuclear wastes with shorter half lives are stored until they are less dangerous, or even until they are no longer harmfully radioactive and can be disposed of with regular waste.

Different countries categorize waste differently.  The United States places waste into three categories based on where the waste comes from: low level, transuranic, and high level waste.  Most other countries simply categorize waste by the potential effect or radioactivity of the substance.  So, most countries categorize by low level, intermediate level, and high level waste.  Since more countries use the second system, I will refer to the levels of waste as such.

Low level waste includes items such as rags, clothing, filters and anything that may have come into contact with radioactivity during the reaction process and therefore, have relatively short half lives.  These items do not require any type of shielding before handling or being transported, because they are not harmful to humans, and they are often burned or compacted before being disposed of through a shallow burial.  In the United States, there are three commercial land disposal facilities for this low level waste.  However, they only accept a certain amount of waste from certain states.  To put this type of waste into perspective, low level waste accounts for approximately 90% of volume of radioactive waste, but only 1% of the radioactivity.

The next step up is intermediate level waste, which has slightly higher levels of radioactivity than that of low level waste.  This includes materials such as chemical sludge, resins, and contaminated materials from the reactor.  These require some shielding and a little more care for disposal, for they are normally sealed in concrete or bitumen so as to protect humans and the environment from their radiation.

Last, and most troublesome, is high level waste.  This comes from the uranium that has been used in a nuclear reaction.  It is the actual fuel that has been used, or the waste left over from reprocessing the used fuel.  This type of waste is the most radioactive of all the waste products and also the most thermally hot.  It accounts for over 95% of all radioactivity in waste from nuclear energy.  Because of it’s radioactivity, high level waste must shielded and disposed of carefully and responsibly.  Furthermore, because high level waste has a long half life, this type of waste can take hundreds of thousands of years to decay.  Herein lies the issue: finding a way to depose of this high level waste in a permanent way that will keep the public safe.  As of now, most waste is stored in temporary locations  such as underwater at the plants or in nearby locations where the waste is bound in borosilicate glass and then sealed inside metal containers.

Storage field for Used Fuel
Storage field for Used Fuel

The United States has been trying to solve this issue for decades.  In 1982, Congress passed the Nuclear Waste Policy Act, which set up a deadline  of 1998 for the national Energy Department to begin moving waste from various plants to a permanent, geological waste disposal site.  However, the United States still does not have said permanent waste disposal site.  In 1987, an amendment was made to the Nuclear Waste Policy that required the Energy Department to look to the remote dessert area of Yucca Mountain in Nevada as a site for this permanent waste disposal site.  Proponents of this plan hailed the site because of it’s remote location, geological makeup, and relatively low cost and socioeconomic to the surrounding area.  Furthermore, scientists deployed a computer system called the Yucca Mountain Total System Performance Assessment  which shows that the planned nuclear waste repository facility will protect the health of nearby residents for at least 10,000 years.   But, political leaders in Nevada call this model “an almost unintelligible mix of fact and wishful thinking.” Critics of the plan were deterred by the permanence of the plan.  They argued that it was hard to extrapolate over thousands of years what impact climate change, or the metal’s durability, or even volcanic activity would have on the site.  Basically, the critics feared that the safeguards put in place to protect those living nearby would not be enough.   And in the end, the critics won out.  The Federal Government halted plans for construction at Yucca Mountain in 2010.  Whether this was a positive or negative decision is up for debate.  However, many agree that “underground storage is a practical necessity and political poison.”  In other words, some sort of permanent underground storage system is imperative because we have a buildup of nuclear waste in the United States, but no where to store it.  However, because of the permanence and controversy of such a solution, no politicians want to push for the building of such a site.  Thus, in the United States, plants keep being built and yet no permanent location has been constructed.

The only country in the world that does have a permanent, geological disposal site in the works is Finland.  Like Yucca Mountain, Onkalo, which is located on Olkiluoto Island, is appealing because of it’s isolated location as well as it’s ability to keep waste in and prevent leaks.  This facility is expertly engineered to safely store waste deep underground and then sealed.  The site is intending to open in 2020 and will continue accepting waste until about 2120, after it has been filled with approximately 5500 tons of high level waste.  If this project is followed through to completion, it will be a huge step towards ensuring the future viability of nuclear energy.

One other method of managing this high level nuclear waste is through recycling the spent fuel.  Currently, in the United States, all of the fuel used in nuclear reactions is disposed of.  This is called an open fuel cycle.

Once Through Fuel Cycle
Open Fuel Cycle

As we know, this plan is flawed not only because the country lacks a long term disposal facility, but also because nuclear waste maintains 95% of it’s energy.  Other countries in Asia and Europe have moved instead to a closed fuel cycle where the spent uranium goes back into the system to power future reactions.

Closed Fuel Cycle
 Closed Fuel Cycle

This is a huge positive of of recycling nuclear energy, that the process actually creates, instead of uses, energy.  This could also act as a way to get rid of the stored waste.  Right now, we could harness enough energy, from recycled nuclear waste alone, to power the entire United States electrical grid for one hundred years.  Unfortunately, recycling nuclear waste does create its own waste in return.  However, this final waste would have a much shorter half life than the other un-recycled waste and would decay to harmless in a matter of a few hundred, as opposed to a few million years.  The United States is still a few decades away from wide-spread commercial recycling of nuclear waste.  However, once mastered, this could be a huge stride on the path for energy sustainability.

All in all, nuclear waste could be a solution to the energy crisis the whole world faces.  The only thing standing in the way, is the question of how to dispose of the waste.  Some temporary solutions have been found.  But, the United States in particular, must figure out a method that takes care of high level nuclear waste in a permanent fashion.  Only then can nuclear energy be a safe and feasible alternative power method.