Sustainable supply of electricity is crucial to comfortable living in homes and attaining economic development in any country. Despite being blessed with enormous green and non-green energy resources, Nigeria has been in a quandary about adequate generation and supply of electricity. The electricity crisis has, over the years, had significant adverse impact on the nation's socio-economic and technological development as well as standard of living of its citizens. This paper examines the problems in the electricity sector and the energy potential of green energy resources in Nigeria. The study reveals that the major source of electricity generation (natural gas) and mode of electricity transmission (a single national grid) in the country have been and are still being constrained by myriad of challenges, hence, the inability of the power sector to satisfy the electricity yearnings of Nigerians till date. The study also reveals that about 1182.375GWh of energy per day could be obtained from green energy resources in Nigeria and the provision of this quantity of energy through decentralized off-grid energy solutions would significantly increase electricity availability as well as accessibility in the country.

Wood waste generation in Nigeria is constantly on the increase as a result of low average percentage timber recovery both in the forests and wood processing industries and increased demand for wood and its products in the country. Being perceived as mere useless materials to be discarded, wood waste has become a menace to public health and the environment in Nigeria due to its indiscriminate disposal practices. This paper therefore aims to highlight the potentials of wood waste as a viable resource for economic growth and sustainable development and thereby pique the people's interest in the proper management and harnessing of wood waste. © JASEM https://dx.doi.org/10.4314/jasem.v21i2.4

Aims: To carry out experimental study of the energy potential of some tropical wood species. Study Design: It involved sample collection, experimental analysis and numerical validation of the obtained calorific values. Place and Duration of Study: National Centre for Energy Research and Development (NCERD), University of Nigeria, Nsukka, Enugu State, Nigeria between November 2016 and September 2018. Methodology: Wood waste (saw dust) from ten (10) selected tropical wood species sourced from sawmills in Benin City, Nigeria were subjected to proximate analysis, ultimate analysis as well as energy content study. Results: Thermal conversion characteristics of low ash content (0.2 – 2.76%), very high volatile matter (87.51 – 90.94%), low moisture content (8.62 – 10.53%.), relatively high carbon, hydogen and oxygen contents as well as low nitrogen and sulphur contents were observed. Obtained calorific values were validated using three already existing correlations. Conclusion: Among the 10 species studied, Afzelia africana (Apa) was found to be best suited for energy generation while Triplocyton scleroxylon (Obeche) was found to be least suited.

This study focused on the design and testing of a downdraft gasifier. The gasifier design was based on a combination of the Imbert and stratified models with some modifications. Sizing of the gasifier was done using empirical relations and some experimental data relating to specific gas generation rate, biomass flow rate, throat diameter and reduction zone diameter etc. The thermal capacity of the gasifier was set at 5 kW. A cyclone separator, an air-cooling unit and a filter unit (containing wood shavings) were coupled to the gasifier's reactor to purify the produced syngas. The gasifier system was tested in a forced draught mode using air as the gasifying medium. The feedstock conversion rate of the gasifier was 1.25kg/hr for wood chunks (10-70mm) and 2.1kg/hr for wood shavings (2-5mm). The syngas produced for both types of wood residues burnt with stable blue flames, indicating minimal tar percentage in the syngas. This signifies that the produced syngas can be safely utilized not only for cooking but also in internal combustion engines to generate electricity.

Waste-to-energy (WTE) technology in Nigeria is still at the infancy stage whereas in Sweden the technology is now so advanced that energy in the form of heat and electricity has commercially been recovered from waste. This study examines waste-toenergy development and its success factors in Sweden with a view to instigating the deployment of a modified Sweden's waste-to-energy model in Nigeria to enhance her WTE capacity. The study was carried out in two phases. The first phase involved field visits to some waste-to-energy plants in Sweden and the second phase was a desk research of available data on current WTE development in Nigeria, Sweden's energy sector as well as factors responsible for its successful WTE development. The result from the study showed that Sweden generated about 2.0TWh of electricity from about 5.7 million tonnes of waste in its WTE plants in 2014. The success of WTE development and growth in Sweden is hugely as a result of the support from the Swedish government via enacting enabling policies and adequate funding. With about 14 million tonnes of combustible waste available in Nigeria, about 4.4TWh of electricity could be generated annually if WTE development in the country receives similar support from the Nigerian government. © JASEM http://dx.doi.org/10.4314/jasem.v20i3.18