22-04-2010SOLAR ENERGY & ITS APPLICATIONS Pre pare d by, Hardik P. So nagra (08BEC169) Ankit Pate l (05BEC128) 1 Introduction 22-04-2010 •Solar energy is in the form of the light and heat. •About 30% of total energy received by the earth is reflected back towards the space. Remaining energy is absorbed by the clouds, oceans and land masses. • •The amount of solar energy reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be obtained from all of the Earth's non-renewable resources of coal, oil, natural gas, and mined uranium combined. • •Solar energy is the primary energy source among all of the renewable source like wave energy, hydro-electricity, wind energy, biomass etc. 2 Classification of solar energy 22-04-2010 Solar energy Active solar energy •Itinclude the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar energy •It include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air. 3 22-04-2010 Solar thermal 4 Solar water heater 22-04-2010 •Solar water heater uses solar collector panel to transfer the heat energy of sun light to the water. • •The unit uses convection (movement of hot water upward) to move the water from collector to tank. Neither pumps nor electricity are used to enforce circulation. • •Material uses into the fabrication of tank is insulator for heat so heat of the hot water can not transfer to the surrounding enviornment and hence water can be keep hot for long time. 5 Solar water disinfection 22-04-2010 •Solar water disinfection, also known as SODIS is a method of disinfecting water using only sunlight and plastic PET (PolyEthylene Terephthalate ) bottles. • •SODIS is a free and effective method for decentralized water treatment, usually applied at the household level and is recommended by the World Health Organization (WHO) as a viable method for it. • •UV-A rays from the sun destroys cell structures of bacteria. •UV-A reacts with oxygen dissolved in the water and produces highly reactive forms of oxygen that are believed to also damage pathogens. 6 Solar cooker 22-04-2010 •Principle : Sunlight is converted to heat energy that is use for cooking purpose. This is done as follows: ─Concentrating sunlight. ─Converting light to heat. ─Trapping heat ─Plastic Sheet 7 1. Box cooker 2. Panel cooker 3. Parabolic dish 22-04-2010 Solar power 8 Photovoltaic 22-04-2010 •Principle : Some materials release electrons when hit with rays of light, which produces an electrical current. • •This effect was discovered by Alexander-Edmond Becquerel. The first solar cell was constructed by Charles Fritts in the 1880. • •There are at least fourteen types of photovoltaic cells, such as thin film, mono crystalline silicon, polycrystalline silicon, and amorphous cells, as well as multiple types of concentrating solar power. • •Efficiency is about 4.5% - 6% for silicon type of Fig : Unit solar cell Fig : 11 MW Serpa solar power plant in Portugal 9 Concentrated solar power systems Øconcentrated solar thermal (CST) Øconcentrated photovoltaic (CPV) Øconcentrating photovoltaic and thermal (CPT) 22-04-2010 •Concentrated solar power systems are divided into : •Principle : Concentrate the sunlight at particular point to convert that energy into another form of energy. 10 Concentrated solar thermal (CST) 22-04-2010 •Concentrated solar thermal (CST) is used to produce renewable heat. • •CST systems use parabolic lenses or mirrors and tracking systems to focus a large area of sunlight onto a small area. • •Each concentration method is capable of producing high temperatures and correspondingly high thermodynamic efficiencies • •They vary in the way that they track the Sun and focus light. • •Solar thermal is more efficient method to produce heat. 11 Concentrated solar thermal (CST) 22-04-2010 12 Fig : Using Flat mirror reflector. (Courtesy of www.visualdictionaryonline.com) Concentrated solar thermal (CST) 22-04-2010 13 Fig : Using parabolic reflector. (Courtesy of www.visualdictionaryonline.com) Concentrated solar thermal (CST) 22-04-2010 14 Fig : Combination of previous both method (Courtesy of www.visualdictionaryonline.com) Concentrated photovoltaic (CPV) • 22-04-2010 •Concentrated photovoltaic (CPV) systems employ sunlight concentrated onto photovoltaic surfaces for the purpose of electrical power production. • •Concentrated photovoltaic (CPV) systems classified as follows: ØLow concentration CPV (concentration of 2-100 suns) Ø ØMedium concentration CPV (concentration of 100300 suns) Ø Ø High concentration (concentration of 300 or more suns) •Concentration method using solar collector is cheaper then solar cell as solar cell is costlier than solar collector. • •Electricity cost for solar collector is about $3/watt. 15 Solar chimney power plant 22-04-2010 •Principle : It uses the principle of solar energy & wind energy both. It also use the principle of green house effect. • •It has a high chimney. (Height arround 1000 mtr.) • •This is surrounded by a large collector roof made from glass or resistive plastic supported on a framework.(Diameter in order of 130 mtr.) • •In the center of the chimney there is a wind turbine, which generate electricity using wind velocity which is due to the solar Energy. 16 Vent Chimney 22-04-2010 17 Green house & Agriculture 22-04-2010 •Agriculture seek to optimize the capture of solar energy in order to optimize the productivity of plants. • •Greenhouses convert solar light to heat, enabling year-round production and the growth (in enclosed environments) of specialty crops and other plants not naturally suited to the local climate. Fig : courtesy of http://en.wikipedia.org/wik i 18 References •http://www.darvill.clara.net/altenerg 22-04-2010 •www.daviddarling.info/images/solar_chimney_po •www.sxlist.com/techref/other/solar/chimpower.htm •http://www.solarcookers.org/basics/how.html •http://en.wikipedia.org/wiki 19