Hydro, Tidal and Wind Power Presented By: E. Ram Singh Asstt. Prof.

WHAT IS HYDRO POWER? The objective of a hydropower scheme is to convert the potential energy of a mass of water, flowing in a stream with a certain fall to the turbine (termed the "head"), into electric energy at the lower end of the scheme, where the powerhouse is located. The power output from the scheme is proportional to the flow and to the head.

HYDRO-POWER PLANT It plays very important role in development of our country. It provides power at cheapest rate being perpetual source of energy. 20% of the total world power is generated using hydro-plants.

Hydrology Meteorology Surface water hydrology Hydrogeology Study of the atmosphere including weather and climate Surface water hydrology Flow and occurrence of water on the surface of the earth Hydrogeology Flow and occurrence of ground water Watersheds

Hydrologic Cycle http://www1.eere.energy.gov/windandhydro/hydro_how.html

Hydrographs Graph of stream flow vs. time Obtained by means of a continuous recorder which indicates stage vs. time (stage hydrograph) Transformed to a discharge hydrograph by application of a rating curve Typically are complex multiple peak curves Available on the web

Hydrographs Introduction There are many types of hydrographs. Hydrograph is defined as a graph showing discharge of flowing water with respect to time for a specified time.

Hydrograph Nomenclature storm of Duration D Precipitation P tl tp peak flow Discharge baseflow Q new baseflow w/o rainfall Time

So …. If we measure the rainfall and put it on a time graph and link that to the amount of water in the river, we have some really useful information! This graph is hydrograph. It plots rainfall against discharge (that is the amount of water in the river as it passes a particular point measured in cubic metres per seconds or cumecs). Changes measured over time is river regime - eg in winter more rain, less evaporation, less vegetation to absorb it.

WE CAN READ THE FOLLOWING FROM THE HYDROGRAPH Rate of flow at any instant during the duration period. Total volume of flow upto that instant as the area under hydrograph denotes the volume of water in that duration. The mean annual run-off. The minimum and maximum run-off for the year.

The Indian Scenario The potential is about 84000 MW at 60% load factor spread across six major basins in the country. Pumped storage sites have been found recently which leads to a further addition of a maximum of 94000 MW. Annual yield is assessed to be about 420 billion units per year though with seasonal energy the value crosses600 billion mark. The possible installed capacity is around 150000 MW (Based on the report submitted by CEA to the Ministry of Power)

Continued … The proportion of hydro power increased from 35% from the first five year plan to 46% in the third five year plan but has since then decreased continuously to 25% in 2001. The theoretical potential of small hydro power is 10071 MW. Currently about 17% of the potential is being harnessed About 6.3% is still under construction.

Major Hydropower generating units NAME STATA CAPACITY (MW) BHAKRA PUNJAB 1100 NAGARJUNA ANDHRA PRADESH 960 KOYNA MAHARASHTRA 920 DEHAR HIMACHAL PRADESH 990 SHARAVATHY KARNATAKA 891 KALINADI 810 SRISAILAM 770

World Trends in Hydropower

World hydro production

Major Hydropower Producers

Major Hydropower Producers Canada, 341,312 GWh (66,954 MW installed) USA, 319,484 GWh (79,511 MW installed) Brazil, 285,603 GWh (57,517 MW installed) China, 204,300 GWh (65,000 MW installed) Russia, 173,500 GWh (44,700 MW installed) Norway, 121,824 GWh (27,528 MW installed) Japan, 84,500 GWh (27,229 MW installed) India, 82,237 GWh (22,083 MW installed) France, 77,500 GWh (25,335 MW installed) 1999 figures, including pumped-storage hydroelectricity “Hydroelectricity,” Wikipedia.org

BLOCK DIAGRAM TRANSFORMER PENSTOCK DAM TURBINE GENERATOR RESEVOIR POWER HOUSE PENSTOCK DAM TURBINE GENERATOR RESEVOIR INTAKE POWER LINE TRANSFORMER

How Hydropower Works Water from the reservoir flows due to gravity to drive the turbine. Turbine is connected to a generator. Power generated is transmitted over power lines.

How Hydropower Works A water turbine that convert the energy of flowing or falling water into mechanical energy that drives a generator, which generates electrical power. This is a heart of hydropower power plant. A control mechanism to provide stable electrical power. It is called governor. Electrical transmission line to deliver the power to its destination.

Sizes of Hydropower Plants Definitions may vary. Large plants : capacity >30 MW Small Plants : capacity b/w 100 kW to 30 MW Micro Plants : capacity up to 100 kW

Sizes of Hydropower Plants Pico hydroelectric plant Up to 10kW, remote areas, away from the grid. Micro hydroelectric plant Capacity 10kW to 300kW, usually provided power for small community or rural industry in remote areas away from the grid Small hydroelectric plant Capacity 300kW to 1MW Mini hydroelectric plant Capacity above 1MW Medium hydroelectric plant 15 - 100 MW usually feeding a grid Large hydroelectric plant More than 100 MW feeding into a large electricity grid

Classification of Hydro electric power station. CLASSIFICATION ON HEAD. High head plant ( < 300 m.) Medium head plant. (60m to 300 m.) Low head plant. ( > 60m.) CLASSIFICATION ON WATER CONDITION Flow of water plant. Storage of water plant. Pump storage water plant.

Micro Hydropower Systems Many creeks and rivers are permanent, they never dry up, and these are the most suitable for micro-hydro power production Micro hydro turbine could be a water-wheel turbine. Pelton wheel (most common turbine.) Others : Turgo, Cross-flow and various axial flow turbines

HYDRO POWER PLANT Head Dams: Are of three categories. Water must fall from a higher elevation to a lower one to release its stored energy. The difference between these elevations (the water levels in the forebay and the tailbay) is called head. Dams: Are of three categories. high-head (800 or more feet) medium-head (100 to 800 feet) low-head (less than 100 feet) Power is proportional to the product of head x flow http://www.wapa.gov/crsp/info/harhydro.htm

Scale of Hydropower Projects Large-hydro More than 100 MW feeding into a large electricity grid Medium-hydro 15 - 100 MW usually feeding a grid Small-hydro 1 - 15 MW - usually feeding into a grid Mini-hydro Above 100 kW, but below 1 MW Either stand alone schemes or more often feeding into the grid Micro-hydro From 5kW up to 100 kW Usually provided power for a small community or rural industry in remote areas away from the grid. Pico-hydro From a few hundred watts up to 5kW Remote areas away from the grid.

Turbine Ranges of Application Boyle, Renewable Energy, 2nd edition, Oxford University Press, 2003

Turbine Design Recommendations Head Pressure High Medium Low Impulse Pelton Turgo Multi-jet Pelton Crossflow Reaction   Francis Pump-as-Turbine Propeller Kaplan Boyle, Renewable Energy, 2nd edition, Oxford University Press, 2003

World’s Largest Dams Three Gorges Itaipú Guri Grand Coulee Name Country Year Max Generation Annual Production Three Gorges China 2009 18,200 MW Itaipú Brazil/Paraguay 1983 12,600 MW 93.4 TW-hrs Guri Venezuela 1986 10,200 MW 46 TW-hrs Grand Coulee United States 1942/80 6,809 MW 22.6 TW-hrs Sayano Shushenskaya Russia 6,400 MW Robert-Bourassa Canada 1981 5,616 MW Churchill Falls 1971 5,429 MW 35 TW-hrs Iron Gates Romania/Serbia 1970 2,280 MW 11.3 TW-hrs Ranked by maximum power. “Hydroelectricity,” Wikipedia.org

Dam Types Arch Gravity Buttress Embankment or Earth

FIRST ELEMENT :- DAMS

Arch Dams Arch shape gives strength Less material (cheaper) Narrow sites Need strong abutments

Concrete Gravity Dams Weight holds dam in place Lots of concrete (expensive)

Buttress Dams Face is held up by a series of supports Flat or curved face

Classification of Hydro electric power station. Classification on operation. Manual plant. Automatic plant. Classification on type of load. Base load plant. Peak load plant.

Element of Hydro power station, Reservoir. Catchments area. Dam. (a) Earthen dam. (b) Masonry dam. (c) Concrete dam. 4. Spill ways. 5. Screen. 6. Fore bay or Intake.

Different type of turbine use in hydro power station 1.High head schemes. (Impulse turbine, pelton wheel) 2.Medium head schemes. (reaction turbine ) 3.Low head schemes. (propeller turbine )

Turbine Design Francis Turbine Kaplan Turbine Pelton Turbine Turgo Turbine New Designs

Turbine Classified

Types of Hydropower Turbines

Classification of Hydro Turbines Reaction Turbines Derive power from pressure drop across turbine Totally immersed in water Angular & linear motion converted to shaft power Propeller, Francis, and Kaplan turbines Impulse Turbines Convert kinetic energy of water jet hitting buckets No pressure drop across turbines Pelton, Turgo, and crossflow turbines

Schematic of Francis Turbine

Francis Turbine Cross-Section

Fixed-Pitch Propeller Turbine

Kaplan Turbine Schematic

Impulse Turbines Uses the velocity of the water to move the runner and discharges to atmospheric pressure. The water stream hits each bucket on the runner. High head, low flow applications. Types : Pelton turbine, Turgo turbine

Impulse Turbines Uses the velocity of the water to move the runner and discharges to atmospheric pressure. The water stream hits each bucket on the runner. No suction downside, water flows out through turbine housing after hitting. High head, low flow applications. Types : Pelton wheel, Cross Flow

Reaction Turbines Combined action of pressure and moving water. Runner placed directly in the water stream flowing over the blades rather than striking each individually. Lower head and higher flows than compared with the impulse turbines.

Analysis of the Chain Turbine With flow rate is 1m3/s, and the head is 20m. Assume H1=19m, H2=1m, the diameter of the sprocket is 1m.

Advantages of Chain Turbine It is run-of-river power plant. Do not worry about the turbidity of water. There is no danger of cavitations. It is simple to construct, repaired and maintenance.

Disadvantages of Chain Turbine The slow rotation of chain turbine leads to high speed ratios when connect to generator at 600 rpm – 1500 rpm. This chain turbine operation is very noisey. Structure of turbine is very big.

Pelton Wheel Turbine

Pelton Wheels Nozzles direct forceful streams of water against a series of spoon-shaped buckets mounted around the edge of a wheel. Each bucket reverses the flow of water and this impulse spins the turbine.

Pelton Wheels (continued…) Suited for high head, low flow sites. The largest units can be up to 200 MW. Can operate with heads as small as 15 meters and as high as 1,800 meters.

Turbine Design Ranges Kaplan Francis Pelton Turgo 2 < H < 40 (H = head in meters)

View of penstock &draft tube in Hydro power plant.

The movement of water can be used to make electricity The movement of water can be used to make electricity. Energy from water is created by the force of water moving from a higher elevation to a lower elevation through a large pipe (penstock). When the water reaches the end of the pipe, it hits and spins a water wheel or turbine. The turbine rotates the connected shaft, which then turns the generator, making electricity.

Hydro electric power plant.` Construction of Turbine. Inlet Outlet Impulse turbine for High head plant.

Hydro electric power plant.` Medium head plant Medium head plant

Top View of Francis turbine in Hydro power station. `

Hydro electric power plant.` Propeller turbine for low head plant.

Construction of penstock in hydro power station.`

View of penstock in Hydropower station.`

Element of Hydro power station, 7. Tunnel. 8. Penstock or pipe line. 9. Surge tank. 10. Draft tube. 11. Tail race. 12. Fish passes. 13. Turbine.

Different type of schemes of Hydro power plant. 1.High head schemes. 2.Medium head schemes. 3.Low head schemes.

PENSTOCK “conveying water from the intake to the power house” PENSTOCK “conveying water from the intake to the power house”. The water in the reservoir is considered stored energy When the gate opens the water flowing through the penstock becomes kinetic energy because it is in motion.

2nd ELEMENT:- INTAKE

TRASH RACK Almost all small hydroelectric plants have a trash rack cleaning machine, which removes material from water in order to avoid entering plant water ways and damaging electromechanical equipment.

INTAKE:- A water intake must be able to divert the required amount of water in to a power canal or into a penstock without producing a negative impact on the local environment.

Working diagram Hydro electric power plant.`

Tailraces:- After passing through the turbine the water returns to the river trough a short canal called a tailrace.

What are Spill ways? A dam failure can have sever effects downstream of the dam. During the lifetime of a dam different flow conditions will be experienced and a dam must be able to safely accommodate high floods that can exceed normal flow conditions in the river. For this reason, carefully passages are corporated in the dams as part of structure. These passages are known as spillways.

Flowing water creates energy that can be captured and turned into electricity. This is called hydropower. Hydropower is currently the largest source of renewable power, generating nearly 10% of the electricity used in the United States. The most common type of hydropower plant uses a dam on a river to store water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which, in turn, activates a generator to produce electricity. But hydropower doesn't necessarily require a large dam. Some hydropower plants just use a small canal to channel the river water through a turbine.

Advantage of Hydro power station. The plant is simple in construction ,robust and required low maintenance. It can be put in the service instantly. It can respond to changing loads without any difficulty. There are no stand by losses. The running charges are very small. No fuels is burnt. The plant is quite neat and clean. The water after running the turbine can be used for irrigation and other purpose.

Disadvantage of Hydro power station. The capital cost of generators, civil engineering work etc is high. High cost of transmission lines. Long dry seasons may effect the delivery of power.

Selection of site for Hydro electric power station. sufficient quantity of water at a reasonable head should be available. The site should allow for strong foundations with minimum cost. There should be no possibility of future source of leakage of water. The selected site should be accessible easily. There should be possibility of stream diversion during construction period. The reservoir to be constructed should have large catchments area, so that the water in it should never fall below the minimum level.

Benefits… Environmental Benefits of Hydro power plant. • No operational greenhouse gas emissions Non-environmental benefits – flood control, irrigation, transportation, fisheries and tourism.

Disadvantages Climatic and seismic effects. The loss of land under the reservoir. Interference with the transport of sediment by the dam. Problems associated with the reservoir. Climatic and seismic effects. Impact on aquatic ecosystems, flora and fauna.

Loss of land A large area is taken up in the form of a reservoir in case of large dams. This leads to inundation of fertile alluvial rich soil in the flood plains, forests and even mineral deposits and the potential drowning of archeological sites. Power per area ratio is evaluated to quantify this impact. Usually ratios lesser than 5 KW per hectare implies that the plant needs more land area than competing renewable resources. However this is only an empirical relation.

Effects Capture of sediment decreases the fertility downstream as a long term effect. It also leads to deprivation of sand to beaches in coastal areas. If the water is diverted out of the basin, there might be salt water intrusion into the inland from the ocean, as the previous balance between this salt water and upstream fresh water in altered. It may lead to changes in the ecology of the estuary area and lead to decrease in agricultural productivity.

Climatic and Seismic effects It is believed that large reservoirs induce have the potential to induce earthquakes. In tropics, existence of man-made lakes decreases the convective activity and reduces cloud cover. In temperate regions, fog forms over the lake and along the shores when the temperature falls to zero and thus increases humidity in the nearby area.

Efficiency of Hydropower Plants Hydropower is very efficient Efficiency = (electrical power delivered to the “busbar”) ÷ (potential energy of head water) Typical losses are due to Frictional drag and turbulence of flow Friction and magnetic losses in turbine & generator Overall efficiency ranges from 75-95%

Hydropower Calculations P = power in kilowatts (kW) g = gravitational acceleration (9.81 m/s2)  = turbo-generator efficiency (0<n<1) Q = quantity of water flowing (m3/sec) H = effective head (m)

Ecological Impacts Loss of forests, wildlife habitat, species Degradation of upstream catchment areas due to inundation of reservoir area Rotting vegetation also emits greenhouse gases Loss of aquatic biodiversity, fisheries, other downstream services Cumulative impacts on water quality, natural flooding Disrupt transfer of energy, sediment, nutrients Sedimentation reduces reservoir life, erodes turbines Creation of new wetland habitat Fishing and recreational opportunities provided by new reservoirs

Environmental and Social Issues Land use – inundation and displacement of people Impacts on natural hydrology Increase evaporative losses Altering river flows and natural flooding cycles Sedimentation/silting Impacts on biodiversity Aquatic ecology, fish, plants, mammals Water chemistry changes Mercury, nitrates, oxygen Bacterial and viral infections Tropics Seismic Risks Structural dam failure risks Proposed projects from: http://www.eia.doe.gov/cneaf/electricity/page/capacity/proposedunits.xls

Governor To maintain the generator at a constant 50Hz frequency, it is necessary to maintain the generator shaft at a constant rotational speed. In the independent hydroelectric power plant, the rotational speed of the micro hydro power generator can be change when loads are added or subtracted from the electrical system.

Governor (2) The system frequency can be maintained constant by eliminating the mismatch between generator and load. Governor is to receipt the frequency signal from the output of generator. And it is compared with standard frequency signal. From these results, governor output signal is coming-out to control the valve of water at the entrance to the turbine.

Summary of Future of Hydropower Untapped U.S. water energy resources are immense Water energy has superior attributes compared to other renewables: Nationwide accessibility to resources with significant power potential Higher availability = larger capacity factor Small footprint and low visual impact for same capacity Hall, Hydropower Capacity Increase Opportunities (presentation), Idaho National Laboratory, 10 May 2005 www.epa.gov/cleanenergy/pdf/hall_may10.pdf

Summary of Future of Hydropower Water energy will be more competitive in the future because of: More streamlined licensing Higher fuel costs State tax incentives State RPSs, green energy mandates, carbon credits New technologies and innovative deployment configurations Significant added capacity is available at competitive unit costs Relicensing bubble in 2000-2015 will offer opportunities for capacity increases, but also some decreases Changing hydropower’s image will be a key predictor of future development trends

What is tidal energy? Tidal power facilities harness the energy from the rise and fall of tides. Two types of tidal plant facilities. 1.Tidal barrages 2.Tidal current turbines Ideal sites are located at narrow channels and experience high variation in high and low tides.

Tides are caused by the pull of the moon and sun on the earth’s oceans Gravitational mass of sun and moon pulls on ocean, causing water to rise and fall

Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity

The world's first large-scale tidal power plant (the Rance Tidal Power Station) became operational in 1966.

Generation of tidal energy Tidal power is extracted from the Earth's oceanic tides; tidal forces are periodic variations in gravitational attraction exerted by celestial bodies. These forces create corresponding motions or currents in the world's oceans. Due to the strong attraction to the oceans, a bulge in the water level is created, causing a temporary increase in sea level.

When the sea level is raised, water from the middle of the ocean is forced to move toward the shorelines, creating a tide. This occurrence takes place in an unfailing manner, due to the consistent pattern of the moon’s orbit around the earth.

The magnitude and character of this motion reflects the changing positions of the Moon and Sun relative to the Earth, the effects of Earth's rotation, and local geography of the sea floor and coastlines.

A tidal generator converts the energy of tidal flows into electricity A tidal generator converts the energy of tidal flows into electricity. Greater tidal variation and higher tidal current velocities can dramatically increase the potential of a site for tidal electricity generation.

Because the Earth's tides are ultimately due to gravitational interaction with the Moon and Sun and the Earth's rotation, tidal power is practically inexhaustible and classified as a renewable energy resource.

Once you've built it, tidal power is free. Advantages:- Once you've built it, tidal power is free.  It produces no greenhouse gases or other waste.  It needs no fuel.  It produces electricity reliably.  Not expensive to maintain.  Tides are totally predictable.  Offshore turbines and vertical-axis turbines are not ruinously expensive to build and do not have a large environmental impact

Disadvantages:- A barrage across an estuary is very expensive to build, and affects a very wide area - the environment is changed for many miles upstream and downstream. Many birds rely on the tide uncovering the mud flats so that they can feed. Fish can't migrate, unless "fish ladders" are installed. Only provides power for around 10 hours each day, when the tide is actually moving in or out. There are few suitable sites for tidal barrages

A major drawback of tidal power stations is that they can only generate when the tide is flowing in or out - in other words, only for 10 hours each day. However, tides are totally predictable, so we can plan to have other power stations generating at those times when the tidal station is out of action.

History of wind power Wind power has been used as long as humans have put sails into the wind. For more than two millennia wind-powered machines have ground grain and pumped water. Wind power was widely available and not confined to the banks of fast-flowing streams, or later, requiring sources of fuel. Wind-powered pumps drained the polders of the Netherlands, and in arid regions such as the American mid-west or the Australian outback, wind pumps provided water for live stock and steam engines.

With the development of electric power, wind power found new applications in lighting buildings remote from centrally-generated power. Throughout the 20th century parallel paths developed distributed small wind plants suitable for farms or residences, and larger utility-scale wind generators that could be connected to electricity grids for remote use of power. Today wind powered generators operate in every size range between tiny plants for battery charging at isolated residences, up to near-gigawatt sized offshore wind farms that provide electricity to national electrical networks.

HISTORY_____ Antiquity Early Middle Ages Late Middle Ages 18th century 19th century 20th century 1900–1973 1973–2000 21st century

WIND POWER - What is it? All renewable energy (except tidal and geothermal power), ultimately comes from the sun The earth receives 1.74 x 1017 watts of power (per hour) from the sun About one or 2 percent of this energy is converted to wind energy (which is about 50-100 times more than the energy converted to biomass by all plants on earth Differential heating of the earth’s surface and atmosphere induces vertical and horizontal air currents that are affected by the earth’s rotation and contours of the land  WIND. ~ e.g.: Land Sea Breeze Cycle

Winds are influenced by the ground surface at altitudes up to 100 meters. Wind is slowed by the surface roughness and obstacles. When dealing with wind energy, we are concerned with surface winds. A wind turbine obtains its power input by converting the force of the wind into a torque (turning force) acting on the rotor blades. The amount of energy which the wind transfers to the rotor depends on the density of the air, the rotor area, and the wind speed. The kinetic energy of a moving body is proportional to its mass (or weight). The kinetic energy in the wind thus depends on the density of the air, i.e. its mass per unit of volume. In other words, the "heavier" the air, the more energy is received by the turbine. at 15° Celsius air weighs about 1.225 kg per cubic meter, but the density decreases slightly with increasing humidity.

Site Consideration for wind power plant High annual average wind speed. Availability of anemometry data. Wind structure at the proposed site. Altitude of proposed site. Local ecology.

Distance to road or railways. Nearness of site to local center. Favorable land cost

Development of wind power in INDIA The India contains enough useable wind resource to produce more electricity than the nation currently uses. Development of wind power in India began in the 1990s, As of 31 March 2011 the installed capacity of wind power in India was 14550 MW, mainly spread across Tamil Nadu (6007 MW), Maharashtra (2310.70 MW), Gujarat (2175.60 MW), Karnataka(1730.10 MW), Rajasthan (1524.70 MW), Madhya Pradesh (275.50 MW), Andhra Pradesh (200.20 MW), Kerala (32.8 MW), Orissa (2MW), West Bengal (1.1 MW) and other states (3.20 MW). It is estimated that 6,000 MW of additional wind power capacity will be installed in India by 2012.

Advantages of Wind Power The wind blows day and night, which allows windmills to produce electricity throughout the day. (Faster during the day) Energy output from a wind turbine will vary as the wind varies, although the most rapid variations will to some extent be compensated for by the inertia of the wind turbine rotor. Wind energy is a domestic, renewable source of energy that generates no pollution and has little environmental impact. Up to 95 percent of land used for wind farms can also be used for other profitable activities including ranching, farming and forestry. The decreasing cost of wind power and the growing interest in renewable energy sources should ensure that wind power will become a viable energy source in the India and worldwide.

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