By James Jeffrey, BBC News

Inside a large ramshackle shed a struck match is held to the end of a metal pipe, and a faint blue flame springs into life.

Zenebech Alemayehu smiles, puts her finger tips to her lips, then towards the flame, a symbolic kiss for her new biogas business.

A single mother with a nine-year-old son to look after, Ms Zenebech, 32, recently bought a local franchise from a company called B-Energy, which aims to provide households across Ethiopia with cheap, portable biogas for cooking.