Title is a bit misleading. Manure is used to produce methane, which is then purified to produce normal-ratio gas. This purified gas can then be burnt in normal generators. In any case, this has been going on for sometime and is nothing new (either for Pakistan or the world). Government policies though make it difficult to achieve mass-scale because there is currently no well-managed system for smaller, private-use, consumption-driven IPPs to sell excess electricity into the system. Why is this important? Because while biogas production rate is constant, usage is not. So when usage dips (such as at night-time), the extra gas has to be flared (i.e. released into the air after putting it on fire). This makes almost all projects economically unfeasible.