Components of Energy System

  Energy is a  complex  process as it is possible to convert it 
  into  different  forms, transport  it, store it in some forms 
  and use it in  various end use modes in  innumerable kinds of 
  places. Thus, an  energy system  essentially consists of four 
  components.  They  are  generation,  transmission / transport, 
  distribution and consumption/utilisation.

  Generation  involves   conversion  of  energy  sources   into 
  acceptable  forms that can be easily  transported. Energy can 
  be  drawn  from  water  falls, sun,  wind  and  from chemical 
  energy  stored  in coal, oil and biomass resources. The major 
  factors  which  influence  the  generation  components  of an 
  energy  system  are  the technologies of generation and their 
  scales,efficiency and costs.Examples of these are electricity 
  generated  from  thermal, hydro  or  nuclear  stations,  coal 
  extraction and oil refinement.The size and site of generating 
  facilities depend on a number of factors like availability of 
  raw   materials ,  land ,  water  and  other  infrastructural 
  facilities. 

  Transmission/transport and  distribution are needed to supply 
  the  useful  forms of energy to various places of consumption.  
  Electricity  from  centralised   power   stations   is   more 
  conveniently  transmitted over long distances by transmission 
  and  distribution  networks.  Sources  like  coal,  oil,  LPG 
  (liquified  petroleum  gas)  and  wood can be  transported to 
  different  places  either  for  direct  use  or  for  further 
  conversion  into  other useful forms, e.g., transportation of 
  coal  or  oil  to  run a thermal power station located near a 
  major  load  centre. Consumption/utilisation  relates to that 
  component  of  an  energy  system where energy is utilised in 
  several end use devices  required to carry out specific tasks. 
  For  example, wood or  LPG is  used for cooking stoves, while 
  electricity is used for lighting.

  Many  energy sources can be used either in direct or indirect 
  mode to  perform a task. Electricity,  kerosene and  firewood 
  can be used in the  direct mode for cooking. In indirect mode, 
  energy from resources need to be converted  in many stages to 
  the  form  required  by  an  end  use  device. An  example is 
  conversion of coal to heat (in a boiler to raise steam), heat 
  to mechanical energy (in a turbine), mechanical to electrical 
  energy  (in a generator), electricity to mechanical energy(in 
  a motor),and mechanical to potential form (in a pump) to lift 
  water  from a well. There may be multiple paths from a source 
  to an end use device,such as, biogas can be used for lighting 
  either  directly  through  a  mantle  lamp  or  converted  to 
  electricity and used  to light a bulb.

  In the  case of a decentralised  system, energy resources are 
  transported directly to places of use, and used in a suitable 
  end  use  device. Some  examples of decentralised systems are- 
  use of firewood for cooking and water heating in the domestic 
  sector, small  industries  like  brick  kilns, tobacco curing, 
  sericulture, etc. However, before  the advent of technologies 
  for  large - scale  exploitation   in  a  centralised  system, 
  decentralised  systems  were  the  only  mode  of energy used. 
  Because of convenience, easy  maintenance, diversity of usage 
  and  reduced  costs  of  operation, energy  production became 
  centralised. Efficiencies, costs,and conversion possibilities 
  of end use devices are some of the factors that influence the 
  final stage of energy system.