Hydropower

1. Hydropower Alex Delgado, Courtney Jones, Destani Lopez

2. 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. Brief History

3. 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. What is it?

4. 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. How efficient is it?

5. 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. Efficiency cont’d

7. 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. How to increase efficiency

8. 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 Development in Other areas

9. Hydropower is the nation’s 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. Is it sustainable?

10. 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 Environmental Benefits

11. 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 Environmental Problems

12. 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 How can we lessen the problems?

13. 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 Hydrokinetics and its Potential

14. 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 state’s 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 The Hydrokinetic Resource

15. 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 Hydrokinetic Technologies

16. 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. Wec’s

17. 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 water—a water level higher than that of the surrounding ocean surface—which generates the pressure necessary to turn a hydro turbine as the water flows out the bottom of the device, back into the sea. Wec’s cont’d

18. 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 Future gains?

19. 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 Hydropower in PA

20. 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. Who agrees with Hydropower?

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