A presentation by,V. Meenakshi & M.Shalini, 2nd year B.Tech CSE
Renewable energy - any sustainable energy whichcomes from natural resources such as sunlight, wind, tides, rain, geothermal energy.Some aspects of Renewable energy It exists perpetually and is abundant. Ready to be harnessed, inexhaustible. Clean alternative to fossil fuels.
About 16% of global final energyconsumption comes fromrenewables, with 10% coming fromtraditional biomass (used forheating) and 3.4%from hydroelectricity. New renewables (small hydro,modern biomass, wind, solar,geothermal, and bio-fuels)accounted for another 3%consumption and are growing veryrapidly. The electrical generation globallyis mainly from hydroelectricity andthe rest from new renewables.
Renewable Energy Hydro energy Wind energy Solar energy Biomass Geothermal energy
History Humans have been using wind power for at least 5,500 years to propel sailboats and sailing ships. Windmills have been used for irrigation pumping and for milling grain since the 7th century AD in Afghanistan, India, Iran and Pakistan.
Wind power is a renewable energy source used to generate electricity byconverting wind energy into mechanical energy. This mechanical energy is thenconverted into electricity by the use of an electrical generator located within eachindividual wind machine. Blowing wind spins the blades of a wind turbine – this device is called a wind turbine and not a windmill A windmill grinds or mills grains or is used to pump water Worldwide there are now many thousands of wind turbines operating, with a total nameplate capacity of 194,400 MW. World wind generation capacity more than quadrupled between 2000 and 2006, doubling about every three years. Off –shore wind turbine
Electricity generationThe blades of a turbine are attached to ahub that is mounted on a turning shaft.The shaft goes through a geartransmission box where the turningspeed is increased.The transmission box is attached to ahigh speed shaft which turns a generatorthat makes electricityIn a wind farm(which is a group of windturbines in the same location used forproduction of electric power), individualturbines are interconnected with amedium voltage (often 34.5 kV), powercollection system and communicationsnetwork. wind farm
Solar energy is the radiant light and heat from the sun. It has been harnessed by humans since ancient times using a range of ever-evolving technologies.Solar energy technologies include use of solar energy for solar heating solar photovoltaic solar thermal electricity solar architecture We can change the sunlight directly into electricity by using solar cells also called as photovoltaic cells
How electricity is generated? When sunlight strikes the solar cell electrons are knocked out loose from the molecule They move towards the treated front surface. An electron imbalance is created between both the surfaces of the solar cell. When the two surfaces are joined by a connector like a wire , a current of electricity occurs between the negative and positive sides. This electricity produced s used for various purposes household and industrially. Use of many solar cells or setting a solar plant provides the purpose.
Small scale solar powered sewerage treatmentplant. Solar water heaters
Generate electricity in geo-synchronous orbit using solar power satellites
Applications of solar technology : Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques use photovoltaic panels, pumps, and fans to convert sunlight into useful outputs. Passive solar techniques include selecting materials with favorable thermal properties designing spaces that naturally circulate air referencing the position of a building to the Sun
Biomass (or Bio-fuels) Biomass is all plant material, or vegetation, either raw or processed, wild or cultivated. Bio-fuel is a type of fuel whose energy is derived from biological carbon fixation. Bio-fuels are derived from biomass conversion, as well as solid biomass, liquid fuels and various biogases. Uses - Industrial process heat and steam, Electrical power generation, Transportation fuels (ethanol and biodiesel) and other products.
Socio-Economic Benefits• Helps developing economies by promoting agrarian communities• Increase in jobs• Increase in trade balance (Indian perspective) due to lesserdependence on foreign resources Bio-refinery A facility that integrates biomass conversion processes and equipment to produce fuels, power, and chemicals from biomass. Analogous to todays petroleum refineries It is based on the “Sugar Platform” and the “Thermo chemical Platform”
Geothermal Energy History : Hot Springs have been used for bathing at least since Paleolithic times The oldest known spa is a stone pool on China’s Lisan mountain built in the Qin dynasty in the 3rd century BC, at the same site where the Huaqing Chi palace was later built.Hot water springs form due to geothermal energy of the earth
Geothermal energy it is thermal energy generated and stored in the Earth. Thermal energy is the energythat determines the temperature of matter. originates from the formation of the planet (20%) and from radioactive decay ofminerals (80%). The Geothermal gradient, which is the difference in temperature between the core ofthe planet and its surface, drives a continuous conduction of thermal energy in the formof heat from the core to the surface. Geothermal power is cost effective, reliable, sustainable, and environmentallyfriendly, but has historically been limited to areas near tectonic plate boundaries. Geothermal power has the potential to help mitigate global warming if widelydeployed in place of fossil fuels.
Schematic representation of an ideal geothermal system
Generation of electricity using steam power plants from geothermal energy The steam rotates a turbine that activates a generator, which produces electricity There are three types of geothermal power plants: dry steam, flash steam, and binary cycle. Dry steam power plants draw from underground resources of steam and is sent to the turbines/generator unit to produce power Flash steam power plants use geothermal reservoirs of water with temperatures greater than 360°F (182°C). This very hot water flows up through wells in the ground under its own pressure. Binary cycle power plants operate on water at lower temperatures of about 225°-360°F (107°- 182°C).
Steam-driven Electric Power Plant1. Cooling tower2. Cooling water pump orCirculating water pump3. Transmission line4. Step-up transformer5. Electric generator6. Low pressure turbine7a. Condensate pump7b. Boiler Feed water pump8. Condenser9. Intermediate pressure turbine10. Steam governor or controlvalve11. High pressure turbine12. De-aerator13. Feed heater14. Re-heater section15. Steam generating heatsource16. Moisture separators