List the disadvantages of using biomass as fuel in the conventional manner. Give two examples of technological input to improve efficiency of these fuels.

Disadvantages of using biomass as a fuel:

a) Pollution: burning biomass for energy in the conventional manner produces lot of gaseous pollution including methane

b) Inefficient: Incomplete burning or fast or slow burning results in low calorific value as compared to other fuels. 

c) Expensive. 

Some technological inputs that can increase efficiency of biomass as a fuel can be:

Convertors which accumulate or concentrate the biomass before usage to increase the calorific value

Using fast growing trees

Better incinerators to carry controlled burning