1. conventional energy source
   1. fossil fuels including arthracite and butaminous, incl petroleum & derivatives
   2. water power or energy stored in water
   3. enrgy of nuclear fission
   4. coal,oil,gas,uranium and hydro comes in this category
   5. will get exhausted eventually
2. non-conventional enrg sources
   1. are also known as renewable source
   2. these are solar, wind, tidal, geothermal, and biomass
   3. availability is abundant and the the source is nature
   4. Solar Energy
   5. solar energy comes to earth from sun, cause current in the atmosphere and oceans, causes the water cycle and generate photosyn
   6. application incl
   7. heating and cooling of res building
   8. water heating
   9. solar cookers
   10. solar engines for water pumping
   11. solar electric power generation by
       1. solar ponds
       2. steam generators heated by rotating reflectors
       3. reflectors with lenses and pipes for fluid circulation
   12. Wind Energy
   13. can be used for generation of electricity
   14. the energy available in the wind over earth surface is 16*10power7 MW
   15. Indirect source of solar energy
   16. utilized to run wind mill which in turn drives the generator
   17. provides mechanical power like water pumping
   18. Energy from Biomass
   19. It means organic matter
       1. the simple reaction is H2O+CO2--------------CH2O+O2 CH2O+O2---------------CO2+H2O+112KCAL/MOLE
   20. It is produced in nature by the means of photosynthesis
   21. therefore large amt of carbondioxide can be produced by growing say algae in plastic tubes, ponds and drying.
   22. the algae can be burned for the production of heat which can be converted into electricity through conventional means
   23. can also be processed to produce liquid and gaseous fuels
   24. biomass resources includes the following
       1. concentrated waste
       2. dispersed waste residue
       3. harvested biomass
   25. Ocean Thermal Energy Conversion
   26. A large amt of solar energy is stored in the tropical oceans. the surface of water acts as a solar heat collector while the upper layer of sea acts a heat storage reservior .
   27. heat contained in the oceans can be converted into electricity by utilizing the fact that the temp difference exist between the warm surface water and colder water at depth at abt 20- 25degK.
   28. the surface water which is at high temp is used an organic fuild, the vapours of which runs the heat engine.
   29. the exit vapours are condensed by pumping cold water
   30. OTEC method works on a closed Rankine cycle
   31. the organic fluid is ammonia,propane, R-12 etc
   32. Topic
       1. Fuel cells
          1. it may be defined as the electrochemical device for the continous conversion of free energy change in chemical reaction to electrical energy.
          2. It operates with continous replinshment of fuel and the oxidants at the active electrode area does not require recharging
          3. main components of fuel cell are
             1. fuel electrode
             2. an oxidant
             3. an electrolyte
          4. hyd oxy fuel cell are the most efficient and highly developed
          5. two porous carbon or nickel electrode is immersed in electrolyte
          6. catalyst is embedded in nickel electrode
          7. the electrolyte is basically 30% KOH
          8. pls see the cell reaction
3. Alternative fuel
   1. known as non-conventional or advanced fuel
   2. or any materials or substance that can be used as fuel
   3. the main purpose is to store energy
   4. which is stable and is capable of transportation
   5. able to do mechanical work
   6. The possible alternative fuel available for ic engine are
   7. Biofuel
   8. Alcohol fuels
   9. Hydrohen
   10. HCNG
   11. Liquid Nitrogen
   12. Compressed Air
   13. Alternate fossil fuels
   14. Nuclear power
   15. Need for alternative fuels
   16. Due to scarcity in the near future
   17. excessive demands for energy
   18. fossil fuels emit CO2
   19. global waming
   20. these are entirely renewable
   21. cost effective extraction
   22. eco friendly and safer to use
4. solar energy collectors
   1. a solar collector is a device for collecting solar radiation and transfer the energy to the fluid passing through it.
   2. there are basically two types of collectors
      1. non concentrating or flat plate type
      2. concentrating type solar collector
   3. Flat plate solar collector
   4. it can be explained with the help of a typical liquid collector
   5. it basically consists of a flat surface with high absorptivity for solar radiation
   6. typically a metal plate usually of CU, Steel or Al with tubing of copper is generally used
   7. the absorber plate is made from metal sheet of 1 to 2 mm thick
   8. the tubes are lined & are integral with the absorber plate
   9. heat is transferred from the absorber plate to the point of use
   10. thermal insulation of about 5 to 10 cm is usually placed behind the absorber plate
   11. the front covers are generally glass that is transparent to the incoming solar radiation and opaque to the infra red reradiation
   12. Concentrating Collector
   13. Focusing collector is a device to collect solar energy with high intensity of solar radiation
   14. Such type of collectors generally use optical system in the form of reflectors and refractors
   15. again classified into two types
       1. line focusing
       2. point focusing
   16. the main types are
       1. parabolic trough collector
       2. frensal collector
       3. mirror strip collector
5. Solar energy storage system
   1. thermal energy storage
      1. sensible heat
         1. water storage
         2. pebble bed storage
      2. latent heat
   2. electrical storage
      1. capacitor storage
      2. inductor storage
      3. battery storage
   3. chemical storage
      1. chemical
      2. thermo-chemical
   4. electomagnetic storage
   5. mechanical energy storage
      1. pumped hydrogen electric storage
      2. compressed air
      3. Flywheel
6. Wind Energy
   1. site selection consideration
      1. High average annual wind speed
      2. availability of anemometry data
      3. availability of wind Vt curve at proposed site
      4. wind structure at proposed sote
      5. Altitude of the proposed site
      6. Terrain and its aerodynamics
      7. Local ecology
      8. Distance to roads or railways
      9. Nearness of site to local centre
      10. Nature of ground
      11. Favourable land cost
      12. other conditions such as icing problems
   2. components of WECS//as per textbook
   3. the aeroturbine converts the moving air to rotary mech energy. In general they require pitch control and yaw control
   4. The purpose of the controller is to sense wind speed. wind direction, shaft speed and torques,output power and generators temperatures
   5. the sub components of the windmill are
      1. wind turbine or rotor
         1. horizontal axis rotor
         2. vertical axis rotors
      2. wind mill head - supports the rotor, housing the rotors bearings. It also houses any control mechanism incorporated like chnaging the pitch of the blades for safety
      3. transmission and control - again the rate of rotation is controlled by the varying the pitch. among the transmission option are mech sys incl fixed ratio gear, belts, chains, pumps and rotors.
      4. Generators - either constant or variable generators are used. variable is most expensive.
      5. supporting structure
         1. the reinforced concrete towers
         2. the pole towers
         3. shell tube tower
         4. the truss tower
7. solar energy measurment devices
   1. Pyrheliometers
      1. It is the instrument which measure beam radiation
      2. in contrast tp pyranometer the sensor disc is located at the base of tube whose axis is aligned with the direction of sun rays
      3. they operate on thermopile effect
      4. problems with this are apenture angle,the circum solar contibution and the impresicion in tracking mechanism.
   2. pyranometer
      1. it is a device which measures total or global radiation over a hemispherical field of view.
      2. The shading ring prevent the beam radiation from falling on the surface and only measures the diffuse component.
8. photovoltaic conversion
   1. the most normal config for a solar cell to make a p-n junction semiconductor is shown
   2. the junction of p and n provide inherent elecric field to separate the charge created by the absorption of sunlight
   3. It is obtained by putting p type in the diffusion furnace containing a gaseous n type dopant like phosphorus
   4. allowing the n dopant to diffuse into the surface abt 0.2 micro meter
   5. the positive and -ve charges created by the absorption of photon are encouraged to drift front and back of solar cell
   6. the back is completely covered by the metallic contact to remove charges to electric field.
   7. the collection of charges from the front is acheived by the aided by fine grid of metallic fingers.
9. Power in the wind
   1. Subtopic 1
10. Lift & Drag
    1. There are two primary physical principles by which energy can be extracted from the wind; these are through the creation of either drag or lift force (or through a combination of the two).
    2. Drag forces provide the most obvious means of propulsion, these being the forces felt by a person (or object) exposed to the wind.
    3. The basic features that characterise lift and drag are: drag is in the direction of airflow • lift is perpendicular to the direction of airflow • generation of lift always causes a certain amount of drag to be developed • with a good aerofoil, the lift produced can be more than thirty times greater than the drag • lift devices are generally more efficient than drag devices
    4. Subtopic 4
11. Horizontal axis wind turbine
    1. they have the main rotor shaft and electrical generators at the top of the tower
    2. small turbines are coupled with a small tail vane
    3. while the big ones are incorporated with a sensor coupled with a servo motor
    4. there is a gearbox which turns slow rotation to quicker rotation
    5. the blades are oriented downward
    6. the rotor blades are continuosly flexed by gravitational, inertia and aerodynamics loads
    7. because of high cost the blade rotor of more than two is not recommended.
12. Vertical axis wind turbine
    1. vertical axis wind turbine have the rotor shaft arranged verically
    2. the key advantage is it does not need to be pointed into the wind to be effective
    3. with vertical axis the generator and gearbox are placed near to ground, so that the tower does nt support it
    4. ease of maintaince
    5. they are installed on the ground or roof top
    6. air flow near ground and object create turbulent flow and will lead issue to turbulence