Biogas as Substitute for Fuel Wood :

  Socio - economic  survey  conducted in villages of Kolar has 
  shown  that  per  capita  requirement of fuel wood is around 
  0.7-1.1 t/yr. If  30%  population opts for biogas, then fuel 
  wood  saved in the  district  would be in the range 2.6-4.10 
  lakh tonnes/year.

  By  switching  over  to  biogas,  the  drudgery  involved in 
  collection and transport of fuel wood (which takes about 5-6 
  hours per day) gets  reduced, and also  reduces cooking time 
  from  4-6 hours (fuel  wood stoves) to  1.5-3 hours  (biogas 
  stoves) a day.