Energy efficiency and environmental life cycle assessment of Jatropha for energy in Nigeria: a 'well-to-wheel' perspective

There is a large imbalance between demand and supply of energy in Nigeria, with inefficient power supply being the country's greatest economic bane. Aside energy crisis, fuel is a luxurious commodity and petroleum diesel is the predominant fuel for power generation, particularly in the industrial sector. As a result, the country suffers from forced power outages, and persistent black out while residents and industries are forced to depend on self-generated electricity. These have notably reduced industrialization and increased environmental pollution across the country. This paper proposes the use of Jatropha biodiesel as a substitute fuel to petroleum diesel. It examines the energy efficiency and environmental life cycle impact of the production and use of 1MJ of Jatropha biodiesel in a typical 126 MW (ISO rating) industrial gas turbine power plant with multi-fuel capability using life cycle assessment methodologies and principles. A net energy ratio of 2.37, 1.54, and 1.32 and fossil fuel savings of 58%, 36% and 27% were achievable under three farming system scenarios: a) base-case rain-fed, b) base-case irrigated and c) large scale farming system. Also, an environmental benefit with GHG savings of 19% was attainable under the three farming scenarios. The results demonstrate that the contribution of GHGs and effect on climate change is most significant with the end use of the fuel. It also highlights the importance of clear definition of the reference system which should be indicative of the local production system and comparative to the system under study. A favourable business and economic climate driven by demand is proposed for Independent Power Producer (IPP) to generate power for offgrid users instead of generating power for the national grid using a decentralized Jatropha biodiesel production system coupled to waste to energy technologies. This could significantly improve the energy situation; diversify the energy generation mix and fuel supply in Nigeria, especially for small-scale businesses and the rural population.