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.
THEORETICAL- The maximum potential that exists.
TECHNICAL- It takes into account the cost involved in exploiting a source (including the environmental and engineering restrictions)
ECONOMIC- Calculated after detailed environmental, geological, and other economic constraints.
Continent Wide distribution REGION THEORETICAL POTENTIAL (TWh) TECHNICAL POTENTIAL (TWh) AFRICA 10118 3140 N. AMERICA 6150 3120 LATIN AMERICA 5670 3780 ASIA 20486 7530 OCEANIA 1500 390 EUROPE 4360 1430 WORLD 44280 19390
Top ten countries (in terms of capacity) COUNTRY POWER CAPACITY (GWh) INSTALLED CAPACITY (GW) TAJIKISTAN 527000 4000 CANADA 341312 66954 USA 319484 79511 BRAZIL 285603 57517 CHINA 204300 65000 RUSSIA 160500 44000 NORWAY 121824 27528 JAPAN 84500 27229 INDIA 82237 22083 FRANCE 77500 77500
Theoretical potential is about 40,500 TWh per year.
The technical potential is about 14,300 TWh per year.
The economic potential is about 8100 TWh per year.
The world installed hydro capacity currently stands at 694 GW.
In the 1980s the percentage of contribution by hydroelectric power was about 8 to 9%.
The total power generation in 2000 was 2675 Billion KWh or close to 20% of the total energy generation.
Most of the undeveloped potential lies in the erstwhile USSR and the developing countries .
Worldwide about 125 GW of power is under construction.
The largest project under construction is the Three Gorges at the Yangtze river in China . Proposed potential is 18.2 GW and the proposed power output is 85 TWh per year .
Global Installed Capacity
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)
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.
India’s Basin wise potential Rivers Potential at 60%LF (MW) Probable installed capacity (MW) Indus 19988 33832 Ganga 10715 20711 Central Indian rivers 2740 4152 West flowing 6149 9430 East flowing 9532 14511 Brahmaputra 34920 66065 Total 84044 148701
Region wise status of hydro development REGION POTENTIAL ASSESSED (60% LF) POTENTIAL DEVELOPED (MW) % DEVELOPED UNDER DEVELOPMENT NORTH 30155 4591 15.2 2514 WEST 5679 1858 32.7 1501 SOUTH 10763 5797 53.9 632 EAST 5590 1369 24.5 339 NORTH EAST 31857 389 1.2 310 INDIA 84044 14003 16.7 5294
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 KARNATAKA 810 SRISAILAM ANDHRA PRADESH 770
Installed Capacity REGION HYDRO THERMAL WIND NUCLEAR TOTAL NORTH 8331.57 17806.99 4.25 1320 27462.81 WEST 4307.13 25653.98 346.59 760 31067.7 SOUTH 9369.64 14116.78 917.53 780 25183.95 EAST 2453.51 13614.58 1.10 0 16069.19 N.EAST 679.93 1122.32 0.16 0 1802.41 INDIA 25141.78 72358.67 1269.63 2860 101630.08
Region wise contribution of Hydropower REGION PERCENTAGE NORTH 30.34 WEST 13.86 SOUTH 37.2 EAST 15.27 NORTH-EAST 37.72 INDIA 24.74
Total potential developed in the late 1990s was about 47000 MW with China contributing as much as one-third total potentials.
570 TWh per year from plants less than 2 MW capacity .
The technical potential of micro, mini and small hydro in India is placed at 6800 MW.
Small Hydro in India STATE TOTAL CAPACITY (MW) ARUNACHAL PRADESH 1059.03 HIMACHAL PRADESH 1624.78 UTTAR PRADESH & UTTARANCHAL 1472.93 JAMMU & KASHMIR 1207.27 KARNATAKA 652.51 MAHARASHTRA 599.47
Sites (up to 3 MW) identified by UNDP STATE TOTAL SITES CAPACITY NORTH 562 370 EAST 164 175 NORTH EAST 640 465 TOTAL 1366 1010
Small Hydro in other countries
China has 43000 small hydro-electric power stations nationwide to produce 23 million KWh a year. It has 100 million kilowatts of explorable small hydro-electric power resources in mountainous areas of which only 29% has been tapped.
Philippines has a total identified mini-hydropower resource potential is about 1132.476 megawatts (MW) of which only 7.2% has been utilized.
There is about 3000 MW of small hydro capacity in operation in the USA. A further 40 MW is planned.
The turbine and generator are a sealed unit placed directly in the water stream.
Straflo : The generator is attached directly to the perimeter of the turbine.
Tube Turbine : The penstock bends just before or after the runner, allowing a straight line connection to the generator
Kaplan : Both the blades and the wicket gates are adjustable, allowing for a wider range of operation
The inlet is a scroll-shaped tube that wraps around the turbine's wicket gate.
Water is directed tangentially, through the wicket gate, and spirals on to a propeller shaped runner, causing it to spin.
The outlet is a specially shaped draft tube that helps decelerate the water and recover kinetic energy.
The inlet is spiral shaped.
Guide vanes direct the water tangentially to the runner.
This radial flow acts on the runner vanes, causing the runner to spin.
The guide vanes (or wicket gate) may be adjustable to allow efficient turbine operation for a range of water flow conditions.
Francis Turbines (continued…)
Best suited for sites with high flows and low to medium head.
Efficiency of 90%.
expensive to design, manufacture and install, but operate for decades.
Kinetic Energy Turbines
Also called free-flow turbines.
Kinetic energy of flowing water used rather than potential from the head.
Operate in rivers, man-made channels, tidal waters, or ocean currents.
Do not require the diversion of water.
Kinetic systems do not require large civil works.
Can use existing structures such as bridges, tailraces and channels.
Hydroelectric Power Plants in India Baspa II Binwa
Continued … Gaj Nathpa Jakri
Continued… Rangit Sardar Sarovar
Environmental Benefits of Hydro
• No operational greenhouse gas emissions
• Savings (kg of CO2 per MWh of electricity):
– Coal 1000 kg
– Oil 800 kg
– Gas 400 kg
• No SO2 or NOX
– flood control, irrigation, transportation, fisheries and
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.
Disappropriating and resettlement represents a mammoth political and management challenge. Related costs can increase project costs by as much as 10% if planned poorly .
HYDROPLANT COUNTRY POPULATION DISPLACED Danjiangkou China 383000 Aswan Egypt 120000 Volta Ghana 78000 Narmada Sardar Sarovar India 70000 Three Gorges China 2000000
Interference with Sediment transport
Rivers carry a lot of sediments.
Creation of a dam results in the deposition of sediments on the bottom of the reservoir.
Land erosion on the edges of the reservoir due to deforestation also leads to deposition of sediments.
RIVER Kg/m 3 Yellow River 37.6 Colorado 16.6 Amur 2.3 Nile 1.6
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.
Some major/minor induced earthquakes DAM NAME COUNTRY HEIGHT (m) VOLUME OF RESERVOIR (m 3 ) MAGNITUDE KOYNA INDIA 103 2780 6.5 KREMASTA GREECE 165 4650 6.3 HSINFENGKIANG CHINA 105 10500 6.1 BENMORE NEW ZEALAND 118 2100 5.0 MONTEYNARD FRANCE 155 240 4.9
In tropical regions due to decomposition of the vegetation, there is increased demand for biological oxygen in the reservoir.
The relatively constant temperatures inhibit the thermally induced mixing that occurs in temperate latitudes.
In this anaerobic layer, there is formation of methane which is a potential green house gas.
This water, when released kills the fishes downstream and creates an unattractive odor. The only advantage is that all these activities are not permanent.
Many fishes require flowing water for reproduction and cannot adapt to stagnant resulting in the reduction in its population.
Heating of the reservoirs may lead to decrease in the dissolved oxygen levels.
The point of confluence of fresh water with salt water is a breeding ground for several aquatic life forms. The reduction in run-off to the sea results in reduction in their life forms.
Other water-borne diseases like malaria, river-blindness become prevalent.
Methods to alleviate the negative impact
Creation of ecological reserves.
Limiting dam construction to allow substantial free flowing water.
Building sluice gates and passes that help prevent fishes getting trapped.
Case Study- Volta Lake, Ghana
Volta lake was formed as a result of the construction of the Akosombo Dam.
It was aimed at providing much needed power needs for domestic consumption and for the production of Aluminium.
Even though much study was conducted prior to the construction, many favorable and adverse environmental changes took place.
Enhanced fishing upstream.
Opportunities for irrigated farming downstream.
With the flooding of the forest habitat of the Tsetse fly, the vector of this disease, the problem of Sleeping Sickness has been substantially reduced.
Diminished fishing downstream.
Growth of long lasting weeds like Pistia, Vossia spp. Ceratophyllum.
Ceratophyllum’s submerged beds house large populations of Bulinus snails the vector of Schistosomiasis.
Growth of dangerous water weeds like water hyacinth.
Prevalence of river blindness (Snchocerchiasis), bilharzia (Schistosomiasis), malaria and Sleeping Sickness (Trypanosomiasis
Technology to mitigate the negative environmental impact.
Construction of fish ways for the passage of fish through, over, or around the project works of a hydro power project, such as fish ladders, fish locks, fish lifts and elevators, and similar physical contrivances
Building of screens, barriers, and similar devices that operate to guide fish to a fish way
Evaluating a new generation of large turbines
Capable of balancing environmental, technical, operational, and cost considerations
Developing and demonstrating new tools
to generate more electricity with less water and greater environmental benefits
tools to improve how available water is used within hydropower units, plants, and river systems
Studying the benefits, costs, and overall effectiveness of environmental mitigation practices
ECONOMICS OF HYDRO POWER
Global HP Economics
Cost of HP is affected by oil prices; when oil prices are low, the demand for HP is low.
Thesis was tested in the 1970s when the oil embargo was in place
More plants built, greater demand for HP
Reduces dependency on other countries for conventional fuels
Local HP Economics
Development, operating, and maintenance costs, and electricity generation
First check if site is developed or not.
If a dam does not exist, several things to consider are: land/land rights, structures and improvements, equipment, reservoirs, dams, waterways, roads, railroads, and bridges.
Development costs include recreation, preserving historical and archeological sites, maintaining water quality, protecting fish and wildlife .
Hydro costs are highly site specific
Dams are very expensive
Civil works form two-thirds of total cost
– Varies 25 to 80%
Large Western schemes: $ 1200/kW
Developing nations: $ 800 to $ 2000/kW
Compare with CCGT: $ 600 to $800/kW
Compared with fossil-fuelled plant
– No fuel costs
– Low O&M cost
– Long lifetime
Cost and Revenue of HP
Comparison with CCGT
Payback-HP has higher payback time(25 years)
Net present value (NPV)
Effect of discounting payback
Effect of discounting payback: CCGT
Discounting and NPV
Effect of discounting
– Hydro’s high capital cost at near full value
– Its additional revenue far in future less
– CCGT has higher NPV
– Cost per kWh produced
– Discount costs and production
HP has greater cost
– 2 to 7 p/kWh typical range for HP
– 1.5 to 2.5 p/kWh for CCGT
Overall CCGT appears to be the better investment
Environmental or operational benefits not considered
Overall HP is still a better investment for future
Small HP costs
Machinery-includes turbine, gearbox or drive belts, generator, water inlet control valve.
Civil Works-includes intake and screen to collect the water, the pipeline or channel, turbine house and machinery foundations, and the channel to return the water back to the river-site specific
Small HP costs
Electrical Works-control panel and control system, wiring.
External Costs-includes the services of someone to design the installation, costs of obtaining a water license, planning costs and cost of connection to the electricity network
-these two depend on maximum power output
Typical costs of 100KW plant Low head High head £1000s £1000s Machinery 30 - 90 15 - 60 Civil works 10 - 40 20 - 40 Electrical works 10 - 20 10 - 20 External (no grid connection) 8 - 15 8 - 15 ________________ ________________ Total: 58 - 165 53 - 135
Sardar Sarovar Dam
Project planning started as early as 1946.
Project still under construction with a part of the dam in operation.
A concrete gravity dam, 1210 meters (3970 feet) in length and with a maximum height of 163 meters
The gross storage capacity of the reservoir is 0.95 M. ha.m. (7.7 MAF) while live storage capacity is 0.58 M.ha.m. (4.75 MAF).
The total project cost was estimated at Rs. 49 billion at 1987 price levels.
There are two power houses project- 1200 MW River Bed Power House and 250 MW Canal Head Power House. Power benefits are shared among Madhya Pradesh, Maharashtra and Gujarat in the ratio of 57:27:16 respectively.
Environmental Protection measures
About 14000 ha of land has been afforested to compensate for the submergence of 4523 ha of land.
Formation of co-operatives, extensive training to the fisherman, providing infrastructure such as fish landing sites, cold storage and transportation etc.
Surveillance & Control of Water related diseases and communicable diseases.
Extension of Shoolpaneshwar sanctuary to cover an area of 607 sq.km.
Rehabilitation & Resettlement
Individual benefits like grant of minimum 2 ha. of land for agricultural purpose of the size equal to the area of land acquired.
Civil and other amenities such as approach road, internal roads, primary school building, health, centre, Panchayat ghar, Seeds store, Children's park, Village pond, Drinking water wells, platform for community meetings, Street light electrification, Religious place, Crematorium ground etc. are provided at resettled site.
The Three Gorges Project
Being built on the Yangtze river.
Still under construction to supply energy and provide inland transportation.
Project expected to complete in 2009 .
Dam to provide 18.2 GW of power using 26 Francis generators of 700 MW each.
630 Km long and 1.3 Km wide capable of allowing 10,000-ton ocean-going freighters to sail directly into the nation's interior for six months of each year.
More than 2 million people are to be resettled.
The amount of concrete totals 26.43 million cubic meters, twice that of the Itaipu project in Brazil, currently the world's largest hydroelectric dam .
Environmental and Other Concerns
There have been little to no attempts made toward removing accumulations of toxic materials and other potential pollutants from industrial sites that will be inundated. They number more than 1600 in all.
The dam will disrupt heavy silt flows in the river. It could cause rapid silt build-up in the reservoir, creating an imbalance upstream, and depriving agricultural land and fish downstream of essential nutrients. However, sufficient studies have not been conducted.
Potential Hazard also exists. For example, In an annual report  to the United States Congress, the Department of Defense cited that Taiwanese " proponents of strikes against the mainland apparently hope that merely presenting credible threats to China's urban population or high-value targets, such as the Three Gorges Dam, will deter Chinese military coercion ."
Independent reports suggest residents are convinced their compensation is miserly even though China claims its plans will improve the life of those affected.
Archaeologists and historians have estimated nearly 1,300 important sites will disappear under the reservoir's waters including remnants of the homeland of the Ba civilization.