renewable sources of energy

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2. SPECIFIC QUESTIONS What are the current and projected energy(fuel + electricity) demands? How is the demand for electricity currentlybeing generated? And in the future? What contribution can renewable energymake to future fuel and electricity needs? 3. HOW R ENERGY NEEDS SUPPLIED 4. Present EnergyResourcesFossil fuels - coal, oil, gas are all of limited amounts. Cant be replaced.Nuclear fuels -limited amounts of uranium for nuclear fission reactors butreprocessing of fuel possible.Difficult to estimate how long these fuels will last - but is it sustainableeconomically or environmentally? 5. PRIMARY & SECONDARY ENERGY Modern society requires large quantities ofenergy that are generated from the earthsnatural resources. PRIMARY ENERGY RESOURCES: The fossil fuels (oil, gas, and coal), nuclear energy, falling water ,geothermal , and solar energy. SECONDARY ENERGY RESOURCES: Those sourceswhich are derived from primary resources such aselectricity , fuels from coal, gasoline or petrol ,hydrogen ,synthetic natural gas. 6. PRIMARY & SECONDARY ENERGY 7. The DTI List ofRenewable ResourcesWind, Wave and Hydro PowerPhotovoltaics Active Solar HeatingMunicipal and General WastesLandfill Gas GeothermalAgricultural and Forestry WastesEnergy Crops Fuel Cells 8. NUCLEAR ENERGY TODAY 104 US reactors, about 440 World reactors in 30 countries.World-wide, about 34 new reactors are in various stages ofconstruction. 99.5 nuclear GWe is 13% of US installed capacity butprovides about 20% of electricity. In 2007 nuclear energy production in the US was thehighest ever. US plants have run at 92% capacity in 2007, up from 56% in1980. 3.5 GWe of updates were permitted in the last decade.2.0Gwe are expected by 2013 and more by 2020. 48 reactor licenses extended, from 40 years to 60 years ofoperation , 17 more reactors in process. 9. Forms of Renewable Energy 10. SOLAR RADIATION SOLAR HEATING PANELS /PASSIVE SOLAR CELLS / PHOTOVOLTAIC CELL SOLAR POWER GENERATION 11. SOLAR CELL/PHOTOVOLTAIC CELL Photovoltaic systems convert solar energydirectly into electricity. They have efficienciesnear 10%. convert light into a small electrical output -milliwatts output. need a bank/array of cells for useful output. cost of cells is high but reducing. 12. Photovoltaics on Buildings PV arrays, generating around 54kW (peak)with a total area of 430m2, form the slopingglazed roofs of the atrium spaces in the fourmain buildings. Ove Arup has designed the system to matchthe annual electricity demand of the supplyand extractor fans, effectively providing zero-energyventilation systems. 13. SOLAR ROOF TILESRoof mounted solar panels (Solar century) 14. Integrated solar tiles installed by Solar Centuryon a current development in Milton Keynes byEnglish partnership and Bloor homes 15. Solar Power Generation Located where it can get large amount ofsunlight/usually in open area like desert/highintensity/long sunlight hours parabolic mirrors reflect/focus suns rays ontometal water pipe located along focal axis ofmirrors. High temperature produced - steam -electrical power generated 16. Wind Turbines 17. Calculation of number of householdssupplied by a windfarm Assume 24 windturbines each generating 0.25MW for 70% of time. In a year this amounts to 3.66 x 107kwhr. If this figure is divided by average amount ofelectricity used by a consumer ie 10,607 kwhrin a year, Answer is 3600 consumers. But 166 of these wind farms = 1000Mw powerstation! 18. Offshore WindCluster Features Larger average wind speed than onshore Easier planning consent Technical expertise exists from oil rig experience Suitable location 19. Mountain region features At average height or sufficient height to getmax wind blow or force for large period oftime . In very large unit the production of electricitywill take place without any pollution exceptnoise pollution 20. Hydroelectric Currently largest source of electricity fromrenewables. Needs guaranteed supply of water. Galloway-West of Scotland - series of lochsand rivers-cascade of flowing water. Kinetic energy of water rotates turbines whichgenerate electricity. 21. Tidal Power Located at some coastal sites - usuallyestuaries and bays with large tidal range. Shape of coastal site above and below sealevel determines range eg Bay of Funday,Severn. At high tide reservoir of water is createdwhich is allowed to ebb through turbineslocated in dam. Expenssive construction. 22. Wave Power Land InstalledMarinePowered EnergyTransformer onIslay, WestCoast ofScotland. Wavegen Co.LIMPET provides 500kW of electricity for the National GridThree floating wave power stations at Lewis/1MW each 23. Biomass cycle of sunlight - photosynthesis - plantgrowth - absorption of CO2 - emission of O2. combustion of wood - heat some plants - alcohol decomposition - methane/landfill gas/fuel forheating. 24. Woodburning Electricity Generation ARBRE is the firstcommercial wood-burningplant of its type in Europe. It produces enoughelectricity for 33,000people from clean andsustainable wood fuelsources. The plant has a 10MWelectricity generatingcapacity and 8MW isexported to the local grid. The fuel for the plant iswood chips from forestryand short rotation coppice. 25. Coppice harvestingFirst Renewables LtdShort rotation coppice harvesting for ARBRE wood-fuelled power station. As treesgrow they store energy from the sun in their biomass. At ARBREs power plant theenergy stored in the biomass is converted to electricity. 26. Straw Burning Power PlantLorry leaving plant after delivering strawElean Power station near Ely,Cambridgeshire generates36MW of electricity and is the worlds largest such facility. Itsupplies 80,000 homes with electricity. 27. Biomass Plant in FifePlant burns poultry litter andproduces 10MW of electricity andfertiliserFluidised bed boiler ensures efficientburning and low emissions 28. Landfill Gas1MW generator at Buckden- BiogasAssociationLandfill gas, Dorset