intro and wind.pdf

ALTERNATIVE ENERGY RESOURCES What are Alternative energy Resources?  Wind  Solar  Biomass  Geothermal  Water  Gas Hydrate Importance  Around 80% energy resources from conventional energy resources (oil (36%), natural gas (21%) and coal (23%))  There is a chance in nea...

ALTERNATIVE ENERGY RESOURCES What are Alternative energy Resources?  Wind  Solar  Biomass  Geothermal  Water  Gas Hydrate Importance  Around 80% energy resources from conventional energy resources (oil (36%), natural gas (21%) and coal (23%))  There is a chance in near future fossil fuel will exhaust  Not clean energy. Only atomic energy is clean but safer use is difficult.  Energy consumption is increasing every year. Importance  No green house gas emission, no air pollution  Diversifying energy supply and reducing dependence on imported fuels  More energy, more economic development  Economic development with installation and other work, local economy improvement  Sustainable energy resources  Helping rural women: less dependent on the fossil wood  Human health: Improved stoves with biogas plants “ WIND ENERGY ”  Wind results from air in motion due to pressure gradient that is caused by the solar energy irradiating the earth  Wind Power: Wind possesses energy by virtue of its motion.Any device capable of slowing down the mass of moving air can extract part of the energy and convert into useful work.  Following factors control the output of wind energy converter : -  * The wind speed  * Cross-section of the wind swept by rotor  * Conversion efficiently of rotor  * Generator  * Transmission system  Principle of Energy Conversion Air density, which linearly affects the power output at a given speed, is a function of altitude, temperature and barometric pressure. Variation in temperature and pressure can affect air density up to 10 % in either direction. Warm climate reduces air density Principle of Energy Conversion  Site Selection Following factors are to be considered for selection of good site for wind power generation:-  High annual wind speed.  No tall obstructions for a radius of 3 Km.  Open plain or open shore  Top of a smooth, well rounded hill with gentle slopes  Mountain gap which produces wind funneling.  Attitude of the proposed site.  Terrain and it’s aerodynamic  Local ecology.  Distance to roads and railways.  Nature of ground.  Nearness of site to local centre\users.  Favourable land cost.  Generating System Wind - electric conversion system consists of the following components :- 1) Wind Turbine(WT)- Converts wind energy into rotational(mechanical) energy 2) Gear system and coupling (G/C)- It steps up the speed and transmits it to the generator rotor 3) Generator(G)- Converts rotational energy into electrical energy 4) Controller(C)-Senses wind direction, wind speed generator output and temperature and initiates appropriate control signals to take control action. 5) Yaw motor gear- The area of the wind stream swept by the wind turbine is maximum when blades face into the wind. Alignment of the blade angle with respect to the wind direction to get maximum wind energy can be achieved with the help of yaw control that rotates wind turbine about the vertical axis. Limitation  1. Wind energy is available in dilute and fluctuating in nature.  2. Unlike water energy wind energy needs storage capacity because of irregularity.  3. Noisy operation:-Large unit can be heard many km away.  4. It has relatively high overall weight because they involve construction of high towers and include gearbox, hub and pitch changer, a generator coupling shaft.  5. Large areas are needed.  6. Present system is neither maintenance free not practically reliable.