In addition, the estimated reserve of tar sands and proven reserves
of coals are about 30 billion barrels of oil equivalent and
639 million tonnes (with inferred reserves of about 2.75 billion
tonnes), respectively (Adaramola and Oyewola, 2011). On the
assumption that new oil and gas reserves are not discovered, it is
estimated that the crude oil reserves should run out within the
next 50 years and the proven natural gas reserves should run out
in about 115 years (Ojolo et al., 2012). This inadequacy of energy
supply limits economic growth, restricts socio-economic activities
and adversely affects the quality of life. The need for increased energy
especially in Sub-Saharan Africa where only 58% of the population
is served with safe and clean water supply (WHO, 2005) has
made biogas technology a welcomed development. The development
of biogas technology will facilitate the achievement of the Millennium Development Goals (MDGs) of the United Nations
(Alfa et al., 2014).