Hydropower

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Hydropower

• Alex Delgado, Courtney Jones, Destani Lopez

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Brief History

• Since ancient times, hydro-power has been used
  for irrigation and the operation of various
  mechanical devices, such as watermills, sawmills, 
  textile mills, dock cranes, domestic lifts, power
  houses and paint making.
• Since the early 20th century, the term has been
  used almost exclusively in conjunction with the
  modern development of hydro-electric power, which
  allowed use of distant energy sources.

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What is it?

• Hydro-power is power derived from the energy of
  falling water and running water, which may be
  harnessed for useful purposes.
• Kinetic energy of flowing water rotates the
  blades or propellers of turbine, which rotates
  the axle that is connected to a coiled generator.

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How efficient is it?

• In comparing hydropower to other energy
  generators, the other generators take less time
  to design, obtain approval, build and recover
  investment. However, they have higher operating
  costs and typically shorter operating lives
  (about 25 years).
• High capital cost low maintenance. Typically a
  hydro plant in service for 40 - 50 years can have
  its operating life doubled with simple low cost
  maintenance.
•  Comparing the cost of electricity with the
  initial investment of a hydropower system, the
  pay back period is short. Theoretically, a hydro
  plant should be able to produce electricity for a
  fixed amount during the life span of the unit.
  The operating costs should not change because
  there is no associated price to the water. Unlike
  in fossil fuel plants, the price of natural gas,
  coal, etc. fluctuates depending on what the
  market is doing.
• Hydropower has about a 90 efficiency rating.

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Efficiency contd

• Demands for power vary greatly during the day and
  night. These demands vary considerably from
  season to season, as well. For example, the
  highest peaks are usually found during summer
  daylight hours when air conditioners are running.
• Other means of energy can handle base load energy
  needs due to their long startup.
• Where hydro generators can be started and stopped
  almost instantly making then great to handle peak
  demands.
• There is almost pumped storage which can help
  with peak demands as well.

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How to increase efficiency

• Electricity Market
• Changes in the management of electricity markets
  would also create more opportunities for
  hydropower. 
• Operational Improvements
• Existing plants are eligible for several
  operational changes. The report finds that plant
  optimization could increase the performance of
  these plants and raise revenue for power plant
  operators 1-3 percent.
• Another operational change could be compensating
  hydropower for providing reliability and security
  to the grid, which would increase income to each
  plant by about 40 percent.

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Development in Other areas

• Traditionally been public financed
• Today, there is shortage of public finance
• Need to attract private sector financing
• Mitigation of risks perceived by investors
• Problems
• Mitigation Of Environmental Impacts
• Environmental and social Impact of Dams
• Need for pre planning and continuous assessment
• Post Implementation Monitoring
• Resettlement
• Afforestation
• Power costs and prices to fully reflect
• environmental and social costs
• Those who sacrifice need to be compensated
• Other risks
• Hydrological uncertainties
• high Upfront Capital Investments
• Cost overruns and time slippage
• negative public perception

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Is it sustainable?

• Hydropower is the nations leading source of
  renewable energy
• Satellite imagery shows that the Pacific
  Northwest, home to the most hydropower in the
  United States, has low levels of carbon
  emissions.
• Using hydropower avoids nearly 200 million metric
  tons of carbon pollution in the U.S. each year
  equal to the output of over 38 million passenger
  cars.
• The hydropower industry has invested hundreds of
  millions of dollars each year for environmental
  enhancements at hydro facilities
• The Federal Energy Regulatory Commission issues
  licenses for new non-federal hydropower
  facilities, and for the continuing operation at
  existing projects, and monitors dam safety and
  environmental performance.

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Environmental Benefits

• Hydropower is considered to be a clean renewable
  source of energy
• Emits low levels of greenhouse gases when
  compared to fossil fuel
• The lake that forms behind the dam can be used
  for irrigation, recreational tourism in form of
  water sports, fishing, swimming, boating, etc.
• No waste disposal issues like that of nuclear and
  fossil fuel fired power plants

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Environmental Problems

• Block fish passage to spawning grounds/ocean
• Water at the bottom is inhospitable to fish
• Lowers the amount of dissolved oxygen in the
  water
• Sediments and nutrients can be trapped in the
  reservoir
• Diversion of water impacts stream flow
• Building large hydroelectric power plants can
  lead to major flooding if the dam fails
• They disrupt natural flow and can also cause
  earthquakes, erosion, landslides and other
  serious geological damage

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How can we lessen the problems?

• Fish ladders/ Fish elevators
• Reservoir sediment and river erosion management
• Modifying dam operations to restore river flows
• Building fish hatcheries
• Controlling the temperature and oxygen levels of
  water released from dams
• Conserving and remediating land surrounding
  reservoirs, rivers and dams

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Hydrokinetics and its Potential

• Hydrokinetic technologies produce renewable
  electricity by harnessing the kinetic energy of a
  body of water
• The energy that results from its motion
• The amount of energy that could be captured from
  U.S. waves, tides and river currents is enough to
  power over 67 million homes
• The country could be producing 13,000 MW of power
  from hydrokinetic energy by 2025
• This level of development is equivalent to
• Displacing 22 new dirty coal-fired power plants
• Taking 15.6 million cars off the road

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The Hydrokinetic Resource

• Types of water resources
• Near and off-shore waves
• Extracting only 15 of the energy in U.S. coastal
  waves would generate as much electricity as we
  currently produce at conventional hydroelectric
  dams.
• Ocean tides
• Have the potential to provide us with a reliable
  new source of clean electricity without building
  the dams
• Models of commercial scale tidal energy project
  development proposals found a cost of electricity
  of 4.8-10.8/kWh. In comparison, when wind energy
  entered the market over 20 years ago it had a CoE
  of over 20/kWh
• Ocean currents
• Capturing just 0.1 of the available energy in
  the Gulf Stream could supply Florida with 35 of
  the states electricity needs
• Stream-based hydrokinetic energy
• Estimates expect these water resources
  could fulfill all of the electricity needs for an
  additional 23 million typical homes

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Hydrokinetic Technologies

• Hydrokinetic energy conversion devices
• Wave energy converters (WECs)
• Utilize the motion of two or more bodies
• relative to each other to create energy.
• One of these bodies, called the displacer,
• is acted on by the waves. The second body,
• the reactor, moves in response to the
• displacer
• Rotating devices
• Rotating devices capture the kinetic energy of a
  flow of water, such as a tidal stream, ocean
  current or river, as it passes across a rotor.
  The rotor turns with the current, creating
  rotational energy that is converted into
  electricity by a generator

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Wecs

• Oscillating Water Column Waves enter and exit a
  partially submerged collector from below, causing
  the water column inside the collector to rise and
  fall. The changing water level acts like a piston
  as it drives air that is trapped in the device
  above the water into a turbine, producing
  electricity via a coupled generator.
• Point Absorber  Utilizes wave energy from all
  directions at a single point by using the
  vertical motion of waves to act as a pump that
  pressurizes seawater or an internal fluid, which
  drives a turbine. This type of device has many
  possible configurations. One configuration,
  called a hose pump point absorber, consists of a
  surface-floating buoy anchored to the sea floor,
  with the turbine device as part of the vertical
  connection. The wave-induced vertical motion of
  the buoy causes the connection to expand and
  contract, producing the necessary pumping action.
  Through engineering to generate device-wave
  resonance, energy capture and electricity
  generation by point absorbers can be maximized.

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Wecs contd

• Attenuator Also known as heave-surge devices,
  these long, jointed floating structures are
  aligned parallel to the wave direction and
  generate electricity by riding the waves. The
  device, anchored at each end, utilizes passing
  waves to set each section into rotational motion
  relative to the next segment. Their relative
  motion, concentrated at the joints between the
  segments, is used to pressurize a hydraulic
  piston that drives fluids through a motor, which
  turns the coupled generator.
• Overtopping Device A floating reservoir, in
  effect, is formed as waves break over the walls
  of the device. The reservoir creates a head of
  watera water level higher than that of the
  surrounding ocean surfacewhich generates the
  pressure necessary to turn a hydro turbine as the
  water flows out the bottom of the device, back
  into the sea.

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Future gains?

• The United States has about 78,000 megawatts
  installed capacity of conventional hydropower,
  which provides enough electricity to power more
  than 27 million homes and serve about 75 million
  people
• According to the study released by the National
  Hydropower Association, the U.S. hydropower
  industry could install between 23,000 megawatts
  and 60,000 megawatts of additional capacity by
  2025, or enough to generate electricity for 31
  million additional homes
• The study also estimates that the installation of
  this amount of capacity could create between
  230,000 and 700,000 new jobs

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Hydropower in PA

• Hydropower generated more than 1.5 million
  megawatt hours of electricity in Pennsylvania
  alone from June 2008 to July 2009, nearly enough
  to power more than 150,000 homes
• The Holtwood dam on the Susquehanna River
  generates enough power to provide electricity for
  53,611 homes
• With help from new hydro turbines manufactured at
  Voith Hydro, the facility is being repowered to
  supply an additional 100,000 homes
• A study released estimates the future of
  hydropower to grow from 10 percent of national
  electricity supply to 25 percent

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Who agrees with Hydropower?

• Everyone including the President of the United
  States seems to agree with the idea that
  hydropower can provide a significant proportion
  of electrical demand in the future based on the
  fact that he recently passed the Hydropower
  Regulatory Efficiency Act 2013.

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Work Cited

• http//www.usbr.gov/power/edu/pamphlet.pdf
• http//www.renewableenergyworld.com/rea/news/artic
  le/2013/05/three-ways-to-increase-hydropower-effic
  iency-and-revenues
• http//en.wikipedia.org/wiki/Hydroelectric
• http//www.enviroliteracy.org/article.php/59.html
• http//www.hydro.org/