Prof. R. Shanthini Jan 21, 2012 Module 05 Renewable Energy (RE) Technologies & Impacts - Use of RE sources in electricity generation, in transport, and in other energy consumption modes - Ecological impacts of RES, and mitigation measures

Prof. R. Shanthini Jan 21, 2012 Renewable energy comes from resources that naturally renew themselves (replenishable), and practically never runs out (inexhaustible). Sustainable energy is replenishable within a human lifetime and causes no long-term damages to the environment. Examples?

Prof. R. Shanthini Jan 21, Hydroelectric - Solar Photovoltaics (Solar PVs) - Solar Thermal (Solar T), also known as Concentrated Solar Power (CSP) - Wind - Geothermal - Marine (Wave and Tidal) - Biofuels (Biomass, Bioethanol and Biodiesel) RE technology options:

Prof. R. Shanthini Jan 21, 2012 RE in global final energy consumption, 2008: RENEWABLES 2010 GLOBAL STATUS REPORT Wind/solar/ biomass power generation, 0.7% Biofuels, 0.6% Biomass/solar /geothermal hot water/heating, 1.4% Hydropower, 3.2% Traditional biomass, 13%

Prof. R. Shanthini Jan 21, 2012 Source: BP Statistical Review of World Energy June 2011 Electricity from renewable energy sources:

Prof. R. Shanthini Jan 21, 2012 Source: Table 13, International Energy Outlook 2011 Electricity generation by renewable energy source:

Prof. R. Shanthini Jan 21, 2012 Source: BP Statistical Review of World Energy June 2011 Electricity from renewable energy sources: RE is given by actual annual energy production/consumption (in watt-hours). RE is also given by the installed capacity power rating (in watts). A hydro-electric plant, for example, rarely operates at its full power rating over a full year. Capacity factor of RE plant = Annual average power Installed capacity rating

Prof. R. Shanthini Jan 21, 2012 Comparison of Technologies: TechnologyAvailable energy (PWh/yr) Technical potential energy (PWh/yr) Current installed capacity (GW) Current electricity generation (TWh/yr) Hydroelectric16.5< Solar PVs14900< Concentrated Solar Power (CSP) 9250 – –

Prof. R. Shanthini Jan 21, 2012 Hydroelectric power

Prof. R. Shanthini Jan 21, 2012 Amount of electricity generated depends on the height difference.

Prof. R. Shanthini Jan 21,

Prof. R. Shanthini Jan 21, 2012 Technological statusmature Average growth2.2% per year Total share of global energy mix 16% of electricity in % of electricity in 2035 (potential) Source: International Energy Outlook 2011 Hydroelectric power

Prof. R. Shanthini Jan 21, 2012 Source: International Energy Outlook 2011 World hydroelectric power generation projection: Average growth is 2.2% per year

Prof. R. Shanthini Jan 21, 2012 Source: International Energy Outlook 2011 World electricity generation projection:

Prof. R. Shanthini Jan 21, 2012 Source: International Energy Outlook 2011 World electricity generation projection:

Prof. R. Shanthini Jan 21, 2012 Once the dam is built, the energy is virtually free. No waste or pollution produced. Much more reliable than wind, solar or wave power. Water can be stored above the dam ready to cope with peaks in demand. Hydro-electric power stations can increase to full power very quickly. Electricity can be generated constantly. Dams help preventing flooding (following predicted climate change induced heavy rains), if built over capacity. Hydroelectric power Why hydroelectric power?

Prof. R. Shanthini Jan 21, 2012 The Elwha Dam, a 33 m high dam in Washington state, USA, is one of two huge dams built in the 1910s to power a local paper mill, under the direction of Thomas Aldwell. Hydroelectric power The reservoir that fills the valley behind the dam is now known as Lake Aldwell.

Prof. R. Shanthini Jan 21, 2012  River bed is eroded by lack of sediment needed to create suitable habitats for spawning (25 million cubic yards of sediment have piled up behind the dam over time).  Water stays for so long in the Lake Aldwell and Lake Mills (created by damming), it warms up to about 16°C (which would have been 0°C in the absence of dam).  These high temperatures are unnatural for spawning fish.  High temperature also increases parasite populations, which wipe out two thirds of a spawning population.  Natural flow patterns (which promote the health of native species and help eliminate non native species) are evened out by the reservoirs and dams. Hydroelectric power Effects of dam on river habitat:

Prof. R. Shanthini Jan 21, 2012 The Elwha Dam is being dismantled since Sept It is a 3-year project costing $351 millions. Removal of dam will restore the fish habitats, will create an additional 715 acres of terrestrial vegetation, and improve elk habitats. Hydroelectric power

Prof. R. Shanthini Jan 21, 2012 The Three Gorges Dam project in China Installed capacity: 22,500 MW Project cost: 39 billion US$ Hydroelectric power Length: 2.3 km Height: 101 m

Prof. R. Shanthini Jan 21, has flooded a total of 632 km² area - displaced 1.24 million people - washed away 13 major cities (submerging cultural and archaeological sites) - causing dramatic ecological changes - used 27,200,000 m 3 of concrete, 463,000 tonnes of steel and moved about 102,600,000 m 3 of earth. - when the water level is maximum at 175 m over sea level (110 m above the river level down stream), the reservoir created is about 660 km in length and 1.12 km in width on average, and contains 39.3 km 3 of water. Hydroelectric power The Three Gorges Dam project

Prof. R. Shanthini Jan 21, 2012 Hydroelectric power The Twin Aswan Dams of Nile river Installed capacity of 2100 MW. Length: 3.8 km Height: 111 m

Prof. R. Shanthini Jan 21, 2012  provide protection from floods and droughts  load of rich fertilizing silt are deposited in reservoirs instead of the delta  lack of natural fertilizer has resulted in an increase in erosion of the river and Nile Delta, and an increase in the use of chemical fertilizers  chemical fertilizers have to be imported and thus cost money for the farmers, and it also causes pollution of the surrounding environment due to runoff.  chemical fertilizers contain high levels of Nitrogen and Phosphorous which are harmful to the water resources Hydroelectric power The Twin Aswan Dams

Prof. R. Shanthini Jan 21, 2012 Barriers in the natural flow of a river prevents fish from migration, alters ecosystems, and threatens the livelihoods of local communities. The world's 52,000 largest dams release 104 million. metric tons of methane (a greenhouse gas) annually. Reservoirs fill up with sediment and cost billions to dredge. Failure of a dam will have catastrophic consequences. Loss of land as well as flooding of areas such as natural habitats and existing settlements. The future generations must pay for destroying dams. Hydroelectric power What are the problems with hydroelectric power?