Wind Power in the United States and Abroad

Modern-day science has provided humans with many different ways to generate power. Harnessing the power of wind to create energy is an extremely cost-effective and low-carbon technology among the options of energy production today. Wind power produces no greenhouse gases and can generate large amounts of power while using small amounts of land.¹

The average lifetime output of a wind turbine is 216 terajoules.²  This is equivalent to 277,778 kWh. The average American household consumes about 911 kWh per year. Therefore, over the course of it’s lifetime, a single wind turbine is capable of providing the yearly amount of required power for an entire year to approximately 305 homes.

How Do Wind Turbines Work?

Wind turbines convert the kinetic energy of wind into mechanical power. In simple terms, wind causes the blades of a wind turbine to turn, and these blades cause a shaft within a turbine to spin. This shaft is connected to a generator, which makes electricity.⁵ In order to view an interactive wind turbine and explore the parts of the system, click here.

 

A detailed look inside a wind turbine. Credit

The amount of power that is produced by a wind turbine is given by the equation:

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where the Greek letter rho (ρ) represents air density, A represents area, and velocity represents wind speed. As shown by the equation, doubling the area of a turbine doubles the power it produces, while doubling the velocity of wind increases the power produced by the turbine by a factor of eight.⁷

In 1919, a German physicist name Robert Betz concluded that the maximum efficiency of a wind turbine in converting kinetic energy into mechanical energy by turning a rotor is 59.3 percent. This maximum power efficiency applies to all wind turbines ever created, no matter variations in design. This efficiency is often referred to as “Betz Limit” or “Betz’ Law”. However, it is impossible for wind turbines to operate at this maximum limit because of various engineering requirements and other factors that complete the wind turbine system. The actual efficiency of wind turbines typically ranges between 10 to 30 percent.⁷

Energy Return on Investment (EROI) of Wind Power

Wind turbines have a net energy gain, meaning they produce more energy throughout their lifetime compared to the amount of energy needed to build the turbine itself. The formula used to calculate the energy return on investment for wind energy is:

EROI = cumulative electricity generated ÷ cumulative energy required to                                                                              build and maintain a turbine

The EROI of a wind turbine, which is expected to have a lifetime of about 20 years, typically ranges between 10 and 25 with an average of 16.² In comparison with other types of energy, wind power has a higher EROI than solar power (based on data from solar PV in Germany) and biomass, while it has a smaller EROI than coal and nuclear power, as displayed in the graph below:

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Wind has many causes, such as the uneven heating of the atmosphere by the sun, irregularities of the earth’s surface, and the earth’s rotation. Therefore, the efficiency of a wind turbine varies depending on these variables, as the air flow which causes the turbine to generate energy varies on geographic location.⁵ Wind turbines are typically built on a land (preferably coastlines, where there is more wind) while some are built off-shore, about 10 km away from the coast.  Off-shore wind parks are able to produce more energy because of increased amounts of wind over the water, while they are more expensive to build and require more energy to transport the energy that they produce.²

An example of an on-shore wind farm. Credit
An off-shore wind farm. Credit

The United States has the greatest installed, land-based wind energy capacity, while the United Kingdom has the greatest installed, off-shore wind energy capacity.⁶ There are currently no off-shore wind turbines in U.S. waters, but the United States Department of Energy has increased funding in order to increase availability of this technology.⁵ The Deepwater Wind project (which is discussed in the following paragraph) is making steps to create the first off-shore wind farm in the United States. The off-shore winds off the coasts of the U.S. provide a promising source of energy because of above average wind speeds. It is estimated that off-shore wind resources could provide the U.S. with over 4,000 gigawatts of power, which is about four times greater than the entire generating capacity currently carried on the U.S. electric grid.⁶ Below is a map of the United States which provides a rough estimate for the potential energy that could be generated from coastlines based on annual average wind speeds:

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Deepwater Wind is a project headquartered in Providence, Rhode Island that is America’s leading off-shore wind developer. It is in the process of developing the Block Island Wind Farm, the first off-shore wind farm in the United States. Deepwater Wind won two competitive state solicitations to become the preferred offshore wind developer for the states of Rhode Island and New Jersey, and also succeeded in the first-ever competitive auction for offshore wind sites held by the U.S. government. Deepwater Wind has obtained over 35 billion dollars of assets in management, and plans to bring wind power to the coasts of New England, New Jersey, New York, and Oregon.¹²

Land Requirements of Wind Power

Depending on the configuration of wind turbines and the spacing between them, the land required to generate wind power varies. Only 1-10% of the total area of wind farms is actually occupied by wind turbines, while the rest of the land is used for grazing, agriculture and recreation.¹ Below is a table that displays the land transformation for multiple wind power plants, measured in meters per gigawatt hour, compared to the land transformations of coal mining (taking into account all of the processes of the energy production systems).

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Note the total land transformation column in the above tables. The power produced each hour per square meter of a wind plant ranges from 1030 to 3230 gigawatts.  In comparison, the power produced each hour per square meter of coal mining ranges from 2.3 to 840 gigawatts, which is extremely less productive than wind power. These numbers show that while the EROI for coal is higher than that of wind power, in terms of the amount of land that is required to produce energy, wind power actually performs much better than coal.

As American and European governments have been making steps to further the progress of wind power, increased funding has led to an increase in the size of wind farms. The expansion of wind farms must be done carefully in order to ensure that optimal turbine spacing is maintained. This is because an increased area of a wind farm results in a change in the drag forced induced by all of the turbines on the farm, thus possibly altering the equilibrium of the atmospheric surface layer.⁴

Challenges Preventing The Further Expansion of Wind Power

Considering the large amounts of power that can be harnessed from wind, one may wonder why wind power isn’t more popular than it is today. In the year 2014, wind was the source of only 1.8% of America’s total electrical energy consumption (renewable energy provides 10%, with wind energy being 18% of that), as displayed in this pie chart:

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Scientists believe that a serious challenge that faces the expansion of wind power is it’s cost. Although the cost of wind power has decreased dramatically over the past decade, the technology to produce wind power still requires a higher initial investment than fossil-fueled generators. According to the EIA, the total cost of wind energy without federal tax and other financial incentives is about 9.7 cents/kilowatt-hour, while the total cost of conventional coal without federal tax and other financial incentives is less (about 9.4 cents/kilowatt-hour).⁸ According to eia.gov’s primary energy production by source graph, which can be viewed here, coal power production has been decreasing since the year 2007. I cannot find the cost per kWh of coal in the year 2007 (or any year before that), but because between 2007 and 2012 the amount of coal production in the U.S. decreased by 25 percent, and the overall price per kWh of electricity has actually risen since then, I can conclude that when coal was being produced in higher numbers in large scale plants the price of coal was even less costly than the previously stated number (9.4 cents/kWh).¹³

Another issue regarding wind power is that wind farms that are capable of producing a lot of energy are often located far away from large cities which need energy. In these cases, transmission lines must be used to transport the energy produced at the wind farm to the cities/areas of civilization, which requires additional costs and additional energy.⁹

Although wind turbines produce very little environmental pollution, those who object to wind power believe that the sound produced by the turbine blades and the overall presence of a large wind farm can negatively affect the “aesthetic” of large plots of land.  In addition, many environmental activists are upset by the threat to wildlife that wind turbines pose. During the early development of wind power in the United States, it was observed that many birds and bats had died from flying into turbine rotators.

According to the Office of Energy Efficiency and Renewable Energy, technological development in recent years and increased funding for research has greatly decreased the negative affects that turbines have on the ecosystems of the land on which they are located.⁹ However, a scientific study done in 2006 on a wind farm located in Zeebrugge, Belgium concluded that each turbine on the farm killed on average 19.1 birds every year and negatively altered the breeding grounds of local bird colonies.¹⁰ This study most likely offers a less biased perspective than the Office of Energy Efficiency and Renewable Energy, but was also done years before the claimed technological development occurred.  Animal activists have been outraged for many years about the deaths of rare species caused by turbines. Below is a news report from 2011 that displays the controversy surrounding wind turbines in the state of California:

Wind power, however, is not the only form of energy generation that has an impact on it’s surrounding environment. For example, solar power poses a danger to the environment in which PV panels are installed because the installation of large panels can cause a detrimental loss of habitat to native species from the area, can result in an interference with rainfall and damage, and can cause injury and death to wildlife who come into direct contact them.¹⁴ Non-renewable electricity generation sources are extremely dangerous to surrounding wildlife due to the chemicals that they emit. According to the New York State Energy Research and Development Authority, “the comparative amounts of SO2, NOx, CO2, and mercury emissions generated from coal, oil, natural gas, and hydro and the associated effects of acidic deposition, climate change, and mercury bioaccumulation, coal as an electricity generation source is by far the largest contributor to risks to wildlife found in the NY/NE region.” While a coal mine itself may not pose immediate physical danger to surrounding wildlife, the chemicals which the process of mining and burning coal produce greatly endanger animals because of the air that they breath (this not only affects wildlife, but the human race as well).¹⁵

While the effect that wind power has on ecosystems can be debated, it cannot be debated that wind power emits much less carbon dioxide, methane, and other dangerous greenhouse gases compared to other forms of energy generation. Wind power is a viable carbon-dioxide emissions free technology. If serious efforts are taken to mitigate climate change in the future, it is likely that the United States electricity sector will have to become dependent on wind power for the production of electricity in order to decrease carbon dioxide emissions.¹¹

Sources used:

  1. http://www.sciencedirect.com/science/article/pii/S1364032108001354
  2. http://www.sciencedirect.com/science/article/pii/S0360544213000492
  3. http://www.cuug.ab.ca/branderr/nuclear/petajoule.html
  4. http://onlinelibrary.wiley.com/doi/10.1002/we.469/full
  5. http://energy.gov/eere/wind/how-do-wind-turbines-work
  6. http://www.nrel.gov/docs/fy10osti/40745.pdf 
  7. http://www.raeng.org.uk/publications/other/23-wind-turbine
  8. http://meic.org/issues/montana-clean-energy/cost-of-wind-vs-fossil-fuels/
  9. http://energy.gov/eere/wind/advantages-and-challenges-wind-energy
  10. http://download.springer.com/static/pdf/721/art%253A10.1007%252Fs10531-006-9082-1.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2Fs10531-006-9082-1&token2=exp=1446134730~acl=%2Fstatic%2Fpdf%2F721%2Fart%25253A10.1007%25252Fs10531-006-9082-1.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252Fs10531-006-9082-1*~hmac=1a40e634f51db78534fad55dae74de4a23b9d6c0d844171bd8bae3015a6adce7
  11. http://www.sciencedirect.com/science/article/pii/S0301421504001740
  12. http://dwwind.com/about/
  13. http://cnsnews.com/news/article/terence-p-jeffrey/electricity-price-index-soars-new-record-start-2014-us-electricity
  14. http://solareis.anl.gov/guide/environment/
  15. http://climatecrocks.com/2013/05/20/why-coal-and-nuclear-plants-kill-far-more-birds-than-wind-power/

Fracking: A Controversial Source of Energy

What is fracking?
Fracking, short for “hydraulic fracturing,” was invented over seventy years ago.¹ It is a technique that extracts gas from conventional wells. Drillers use vertical well shafts to descend 10,000 feet down into the layer of shale deep in the ground, turn the drill 90 degrees, and then drill a series of horizontal wells over a thousand feet deeper into the shale. They then blast a mixture of two to four million gallons of water, chemicals and sand in order to fracture the rock and release natural gas.

A simple visualization of a fracking well
A simple visualization of how fracking works. Credit

In the states of Pennsylvania, New York, and West Virginia, fracking is done in Marcellus shale.² Natural gas wells have been drilled in Marcellus shale for over fifty years, but recent advancements in deep horizontal drilling and fracking have greatly increased the profitability of extracting gas from this shale.

The mixture of water, chemicals and sand that is used in fracking is referred to as “fracking fluid.” Exclusively in the state of Pennsylvania in the year of 2011, about 12 to 20 million gallons of water were use every single day in fracking fluid. About 1,500 horizontal fracking wells used approximately .5% to .8% of the water Pennsylvania used daily.²

The large amount of water that fracking requires is taken from multiple different sources. Fracking in the Marcellus shale uses 72% of its water from water sources in Pennsylvania, such as rivers, groundwater, lakes, and creeks. The remaining water is acquired from drilling companies, abandoned mines, underground pipelines, and rainwater on the well pad. In addition to this water, 1% of fracking fluid is composed of 50 known chemicals. These chemicals are used to prevent microorganism growth and the corrosion of metal pipes, and to maintain fluid viscosity (a fluid’s resistance to flow).³ The sand that is in fracking fluid is used to reduce friction, which allows the fluid to be pumped faster and at a lower pressure.


 

What are some of the effects of fracking?
The invention and increase in popularity of fracking has greatly affected the oil industry. In the month of October in 2013, for the first time in over 50 years the United States produced more oil than it imported.¹ The costs of heating and electricity have gone down due to the decreased amount of coal consumption. The economy of the United States has also shown benefits because of the increased activity in the gas and oil sector. Barnett Shale, the form of shale found deep in the ground in the state of Texas, is the largest producible reserve of onshore natural gas in our country due to fracking.

Because of  fracking, there is enough domestic gas in the United States to meet our country’s needs for the foreseeable future. The estimated recoverable gas from US shale source rocks using fracking is about 42 trillion cubic meters, which is nearly equal to the total conventional gas discovered in the United States over the past 150 years, and is equivalent to about 65 times the current US annual consumption (according the the IHS, a business-information company in Colorado). The growth in activity of the American gas industry has greatly benefitted our economy. The gas industry accounts for nearly 3 million jobs and 385 billion dollars in direct economic activity.⁴ Stable supplies of gas from fracking depend on a steady rate of new well completions,  and the resulting gains in employment and economic stimulation from new wells attribute to the benefits of fracking.

Data released from the U.S. Energy Information Administration (EIA) over the years of 2005 to 2015 reveals that the consumption of coal has decreased from 1.93733 quadrillion Btu (September 2005) to 1.457655 quadrillion Btu (September 2014), while the average consumption of natural gas has increased from 1.456699 quadrillion Btu to 1.880758 quadrillion Btu (September 2015).¹¹ Although this reveals the positive trend that Americans are consuming less coal, the fact that natural gas consumption has grown may not have a positive effect on our environment. I will explain some of the underlying dangers of increased natural gas production and consumption later in this blog.

The brown line represents natural gas consumption and the blue line represents coal consumption. Credit

Here is the calculation of Btu of coal consumption and natural gas consumption per person in the United States for the years 2005 and 2014:

2005 U.S. Population: 295,500,000 (Google)

2014 U.S. Population: 318,900,000 (Google)

Coal Consumption:

2005 – 1,937,330,000,000,000 Btu/295,500,000 people = 6,556,108.291 Btu/person

2014 – 1,457,655,000,000,000 Btu/318,900,000 people = 4,570,884.29 Btu/person

Natural Gas Consumption:

2005 – 1,456,699,000,000,000 Btu/295,500,000 people = 4,929,607.445 Btu/person

2014 – 1,880,758,000,000,000 Btu/318,900,000 people = 8,591,859.296 Btu/person

As displayed by this data, fracking has effected the way that the United States has consumed natural gas. This in turn has effected the financial matters of the natural gas consumers in our country. From 2007 to 2013 (a time in which the fracking industry experienced an expansion), consumer gas bills decreased by 13 million dollars per year. Per gas consuming household, the decrease was about 200 dollars per year.¹⁰ While many defenders of fracking attribute this positive change completely to fracking, many factors must be considered when it comes to the natural gas industry in our national and global economy. Here is an informational video in which some of the economic benefits of fracking are explained:

However, these benefits come at a deep cost to our environment and those living near fracking wells. Over 15 million people in America live within one mile of an oil or gas well. Some homeowners living near these wells have experienced pollution of their drinking water due to fracking chemicals released from leaking gas wells and disposal ponds, and methane leaks have caused flames to shoot out of some people’s kitchen taps.¹ Leaking well heads can cause severe water contamination when flowback fluid (which contains natural salts, heavy metals, hydrocarbons and radioactive materials from the shale) leak into streams or sink into groundwater. Within the first two weeks of fracking, nearly one fifth of the entire amount of fracking fluid used flows to the surface of the well.⁴ Considering the massive amounts of fracking fluid that are used, as discussed earlier, this is a substantial amount of potentially destructive fluid. The river shown below contains radium levels 200 times greater in the area where fracking fluid was disposed (even after being processed by a treatment plant) compared to other areas of the river.⁸

 

A river in Pennsylvania that has high levels of radioactivity due to fracking flowback. Credit

 

In addition, air quality has been effected by diesel fumes from the truck convoys traveling down rural roads to well pads.¹ There has been a growing awareness of these dangers and the denial of the gas and oil industry has lead to an even greater public outcry. In 2013, a documentary on HBO titled Gasland Part II aired with hopes of “exposing power politics of fracking.” The trailer of this documentary can be viewed below:


One aspect of the fracking controversy is that some people believe fracking has been a cause of a spur of man-made earthquakes in Arkansas, Colorado, Oklahoma, New Mexico, and Texas. However, there is little evidence that fracking actually causes earthquakes.⁵ While some seismic activity is triggered by fracking in wells, the U.S. Geological Survey has stated that none of the recent man-made earth quakes are directly related to fracking. Bill Elsworth, a USGS seismologist, claims “We don’t find any evidence that fracking is related to any of these magnitude 3 earthquakes that we have been studying.”

A perceived benefit of hydraulic fracturing is a decreased dependence on coal. Although fracking reduces coal consumption, evidence has shown that there hasn’t been a change in greenhouse gas emissions. This is because researchers have discovered a recent increase in the release of methane gas. Methane is released from the natural gas wells which are used in fracking and is far more potent than the carbon dioxide that is released when coal is burned. It is estimated that “3.6–7.9% of the lifetime production of a shale gas well (compared with 1.7–6% for conventional gas wells) is vented or leaked into the atmosphere from the well head, pipelines and storage facilities.”⁴ Therefore, although a decrease in coal consumption curtails the emission of carbon dioxide, the release of methane gas still contributes to the climate change of our planet.

A breakdown of the climate footprint and the growing impact of methane due to shale drilling
A breakdown of the climate footprint and the growing impact of methane due to shale drilling. Credit
A visualization of the dangerous trapping ability of methane gas
A visualization of the dangerous trapping ability of methane gas. Credit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

While some methane gas is emitted from natural sources, around sixty percent of total methane emissions are from human activities, such as industry, agriculture, and waste management activities, as displayed in the chart below:

U.S. Methane Emissions by Source. (2013)  Credit

As of 2013, the amount of methane gas released from natural gas and petroleum systems, which includes fracking, was nearly three times the amount that was released from coal mining, and slightly less than twice the amount released from landfills.⁹ As the popularity of fracking has continued to expand in recent years, the amount of methane released from fracking (in the overall natural gas and petroleum systems category) is due to be even larger than depicted in the above pie chart.


 

What is the future of fracking?                                                            Fracking provides our nation with the valuable ability to decrease our dependence on other countries for natural gas. It has contributed to the growth of our economy and a decreased dependence on coal as an energy source. Mark Soback, geophysicst at Stanford University, claims “Fracking comes with promise and with risk . . . it’s clear that it’s a remarkable resource. It’s abundant, and as a transition fuel between today and the green-energy future, natural gas really is the answer.”  Zoback and a team of scientists surveyed the existing data about fracking and concluded that despite the threats that fracking imposes on our environment and the quality of life of American citizens, strictly enforced regulations can help minimize these threats. Regulations could include reducing the amount of toxic chemicals in fracking fluid and closely monitoring the integrity of the well throughout  it’s creation and continued use.⁶ For more information regarding the impending federal regulations for fracking that the Obama administration is currently working on, click here.

Between the years of 2004 and 2011, the United States experienced a 75 percent increase in it’s natural gas reserves because of fracking.⁷ Due to the extreme short-term benefits of fracking that have changed the way our country acquires and consumes natural gas, it is doubtful that the continued development of fracking will be halted any time soon. However, the expansion of fracking in other nations has been a heavily debated topic. In the United Kingdom, a company titled Caudrilla was granted planning permission to begin drilling in Balcombe, West Sussex in early 2013. High amounts of public opposition eventually deterred the company’s progress and they stopped drilling in the area. Although commercial fracking is not yet occurring in the United Kingdom, it is known that there will be an increasing presence of drilling rigs in it’s rural landscapes.⁷  The debate on the expansion of fracking, not only in the UK, but also in the United States and other countries, is one that must take into consideration the opinions of those living near the drills themselves, the effect that it has on the world economy, the impact on climate change due to an increase in methane gas, and the many other important factors that fracking entails regarding the human race and the environment that we live in.

A young member of the anti-fracking protests in Balcombe. Credit

 

 


Sources used:

1: http://www.theguardian.com/environment/2013/dec/14/fracking-hell-live-next-shale-gas-well-texas-us 

2. http://exploreshale.org/#

3. http://physics.info/viscosity/

4. http://www.nature.com/nature/journal/v477/n7364/full/477271a.html#ref2

5. http://www.theguardian.com/environment/2012/apr/18/us-earthquakes-fracking-gas

6. http://onlinelibrary.wiley.com/doi/10.1002/scin.5591820519/full 

7. http://onlinelibrary.wiley.com/doi/10.1111/2041-9066.12032/full 

8. http://www.usatoday.com/story/news/nation/2013/10/02/fracking-radioactive-water-pennsylvania/2904829/ 

9. http://www3.epa.gov/climatechange/ghgemissions/gases/ch4.html

10. http://www.brookings.edu/blogs/brookings-now/posts/2015/03/economic-benefits-of-fracking

11. http://www.eia.gov/beta/MER/?tbl=T01.03#/?f=M&start=200509&end=201506&charted=1-2-3-5-12