Basic Mechanical Engineering (3110006)

BE | Semester-1   Winter-2019 | 03-01-2020

Q1) (c)

List the non-convectional sources of energy. Prepare a short note on solar energy.

List of non-convectional sources of energy:

  1. Solar energy
  2. Wind energy
  3. Tidal energy
  4. Bio energy
  5. Geo thermal energy

Solar energy

Sun is the ultimate source of energy. The energy originates with the thermonuclear fusion reactions occurring in the sun.

It represents the entire electromagnetic radiation (visible light, infrared, ultraviolet, x-rays, and radio waves). Solar energy reaching the earth in tropical zones is about 1kW/meter square per day.

By one calculation, 30 days of sunshine striking the Earth have the energy equivalent of the total of all the planet’s fossil fuels, both used and unused.

Radiated heat energy from the sun can be utilized for both domestic and commercial purposes such as heating of water, distillation of water, refrigeration, drying, power generation, etc.

For power generation there are mainly two technologies - (1) Solar Thermal and (2) Solar Photo Voltaic (PV).

Solar thermal heat energy generate steam which runs turbine to generate power.

Solar PV directly converts sunlight into electricity without using generators or any moving devices.  

Advantages of solar energy

  1. Pollution free and causes no greenhouse gases to be emitted.
  2. Reduced dependence on foreign oil and fossil fuels.
  3. Renewable clean power that is available every day of the year.
  4. Return on investment unlike paying for utility bills.
  5. No operating and maintenance cost.
  6. The excess power can be sold back to the power company if grid intertied.
  7. It can be installed anywhere; in a field to on a building.
 

Disadvantages of solar energy

  1. It is dilute source of energy and spread out.
  2. High initial costs for material and installation.
  3. Needs lots of space.
  4. No solar power at night, so need for a large battery bank.