The  utilisation  of  hydropower  is  mainly for  electricity 
  generation.  The  generator  is  linked  to  a system for the 
  transmission and distribution of electricity.  Big hydropower 
  units  are  generally  linked  to  the  national  or  central 
  electric  grid.  The electricity generation costs per kWh can 
  be low, e.g., for units bigger than 10,000 kW, some one third 
  the costs of fossil  fuel powered systems.  Small hydro units 
  often  serve a local  electric  grid.  The problem here is to 
  achieve an acceptable capacity utilisation.  Specific demands 
  (e.g., for  lighting) together  with  low  off - peak demands, 
  result in low average load factors for the unit. Load factors 
  as low as 15 to 20 per cent are not uncommon, which result in 
  a  very  unattractive  price  per  kWh .  This  is  sometimes 
  aggravated  by  high  maintenance  costs and breakdowns.  The 
  position of mini  and micro units that produce electricity is 
  different ,  as   will  be  discussed  in  the  next  section.  
  Furthermore ,  hydropower  schemes  often   serve  irrigation, 
  fisheries and flood control systems as well.