recommended quantities are reported to be 6 and 1.5 kg in hills and
terai regions [32]. Among indirect benefits, considerable reduction
in diseases was found, a study on such account was done in Nepal
and showed sizable drop in ailments shown in Fig. 2 [33].
A study on residential biogas models in Panam, Tibet and China
resulted that women’s opportunity cost with conventional fuels
was 47.09% to household income. With introduction of biogas units,
household income increased subsequently impacting positively on
opportunity cost contributed by women [27].