Energy  Resources
    Energy resources are those sources from which we can harvest 
    energy. Energy resource can be of two types i.e.
   1.  Non renewable (Conventional) Energy resources.
   2.  Renewable (Non conventional) Energy resources.
          Non renewable Energy resources
 These are the energy resource that are present in a limited quantity 
  and takes long time to form it. If they used continuously they will 
  be depleted .These sources are pollution causing .they are not eco 
  friendly. These take long time to form and once used cannot be 
  regenerated. For example fossil fuel, coals, natural gas etc. The 
  calorific  value  of  non  renewable  sources  are  much  higher  than 
  renewable sources.
      Non renewable Energy resources
  1.  Coal  :  Coal  is  formed  from  the  vegetative  matter  buried 
   beneath the earth. Coal is the most abundant fossil fuel. The 
   coal is  of  three  types  ie;  Hard  coal  (anthracite)  –It  consists 
   about 92-98% of carbon having highest calorific value- 7500-
   8100kcal/gm. Soft coal (bituminous)- It consists about 75-83% 
   of  carbon  and  calorific  value  is  6100-6500kcal/gm.  Brown 
   coal  (lignite)  –  It  consists  60-70%  of  carbon  and  calorific 
   value is 5000-6000kcal/gm.
  2. Petroleum: It is found beneath the earth’s surface. It is formed 
   by  the  decay  of  microorganism  living  in  the  sea  by  heat, 
   pressure and catalytic action. In India the oil drilling centers 
   are Digboi, Dibrugarh, Narharkatiya, Makum, Bay of Cambay, 
   Bombay High etc. It is cleaner  source  than  coal  with  high 
   calorific value.
  3.  Natural  Gas:  It  is  mixture  of  hydrocarbons  and  methane 
   (96%). Natural gas deposits often accompany oil deposits or 
   may occur independently. It can be easily transported through 
   pipelines. 
  4.    LPG: It is liquefied petroleum gas. It is used for 
   domestic purpose. It is mixture of butane propane. It 
   is obtained by converting petroleum into liquid form 
   under pressure.
  5.  CNG: It is compressed natural gas which is used as 
   an  alternative  to  petrol  and  diesel  for  transport  of 
   vehicles. It is cleaner source than diesel.