Renewable Energy Resources:
Solar EnergyWind Energy
Maulik Bhagat
Solar Energy
SOLAR ENERGY
• Solar energy is the ultimate source of energy from millions of years and it is a renewable energy.
• This energy consists of radiant light and heat energy from the sun.
• Out of all energy emitted by sun only a small fraction of energy is absorbed by the earth.
• Using present solar techniques some of the solar energy reaching the earth is utilized for generating electricity etc….
• Even then the energy demand met by using solar energy is very less.
How solar energy is used
• We can use solar energy by converting it to electrical energy . So we must use a device called solar panels which can convert the light energy into electrical energy.
• Solar panel is a group of solar cells.• Solar cells works on the principle of photoelectric effect.
PHOTOELECTRIC EFFECT
• When a light of certain frequency falls on the surface of a metal , electrons will absorb the energy . If incident light energy is greater than the work function(minimum energy required to remove the loosely bound valence electrons)of the metal ,then the photo electrons will be emitted and the excess energy is converted to the kinetic energy of electron.
USES OF SOLAR ENERGY
• Heaters Green houses • Cars water pumps• Lights Desalination • Satellites Chilling• Dryers Solar ponds• Calculators Thermal
Commercial use • On an office building , roof areas can be covered with solar panels .• Remote buildings such as schools , communities can make use of
solar energy.• In developing countries , this solar panels are very much useful.• Even on the highways , for every five kilometres ,solar telephones
are used.
Applications
Solar car
Solar water HeaterSolar Lights
Advantage
• Renewable and free
• High energy yield
• A very clean source of energy
• No air/water pollution during operation
• Low operating costs
Disadvantages
• Intermittent source
• Energy storage issues
• Low energy density
• Requires pretty much land
Wind Energy
Wind in Action:
• When wind strikes an object, it exerts a force in an attempt to move it out of the way. Some of the winds’ energy is transferred to the object, in this case the wind mill,causing it to move.
How do you convert wind into electricity???
• Wind turbines convert the kinetic energy in the wind into mechanical power.
• This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.
• A wind turbine works the opposite of a fan.• Wind turbines use wind to make electricity. The wind turns the
blades, which spin a shaft, which connects to a generator and makes electricity.
Wind Turbine
Advantages
• No pollution.
• Lowest prices renewable resources
• Don’t produce atmospheric emissions that cause acid rains and green house effects.
• Fuel Diversity & Conservation
• Cost Stability
Disadvantages
• Depending on how energetic a wind site is, the wind farm may or may not be cost competitive.
• Wind energy cannot be stored
• Good wind sites are often located in remote locations
• Wind resource development may compete with other uses for the land and those alternative uses may be more highly valued than electricity generation.
• sometimes birds have been killed by flying into the rotors
Jaisalmer wind farm [The 2 largest off shore wind farm in the world]
London Array[Worlds largest on shore wind farm]
Thank You