The household cooking sector is the largest consumer of energy in Nigeria, using around 80% of the total, 90% of which is derived from biomass, particularly fuel wood [1
]. Although biomass is a renewable resource, the way and the rate at which it is consumed is unsustainable and needs interventions to increase the efficiency of use or find substitutes to ease the burden on the biomass stocks.
Although other sources of cooking energy are used in Nigeria, including liquefied petroleum gas (LPG), kerosene, and electricity, they are expensive compared to biomass, which is available at little or no cost. With over 60% of people earning less than $1 per day [2
], biomass stands as the preferred source of household cooking energy in Nigeria. The availability of electricity and other energy sources is also a major challenge, especially in rural areas. For example, only about 40% of the population is connected to the national grid [3
] with 90% of rural areas having unreliable or no electricity at all [5
]. This virtually eliminates electricity as a source of cooking energy for almost half the population [6
]. Urban dwellings, on the other hand, use electricity, as well as kerosene and LPG for cooking, although fuel wood still dominates owing to the high cost of other energy sources [1
The reliance on fuel wood for the domestic energy supply has exacerbated deforestation, which is also contributing to desertification in some parts of the country [7
]. The annual deforestation rate is estimated at around 3% per year, which is equivalent to the loss of 410,000 hectares of forested land annually [8
]. Another major concern is indoor air pollution from burning biomass in open fires and usually without chimneys, leading to respiratory diseases and premature deaths [9
]. WHO [10
] estimates 79,000 deaths per year in Nigeria from indoor air pollution, mainly caused by biomass burning. Deaths from acute lower respiratory infection in children younger than five years account for about 90% of the total number of deaths from indoor air pollution, with chronic obstructive pulmonary disease in adults of 30 years or over accounting for the rest. Furthermore, constant search for fuel wood represents a large burden for women, particularly in rural areas.
In an attempt to address the health issues and reduce the pressure on biomass resources, the government has in recent times developed plans for improving the efficiency of current cooking methods, dominated by traditional “three-stone” fuel wood stoves, as well as for introducing new technologies [11
]. As a result, advanced cook stoves are starting to be deployed in Nigeria, albeit currently on a small-scale. For example, the German organisation Atmosfair has, thus far, distributed over 10,000 advanced stoves and the American C-Quest Capital has deployed around 6500 units, with the plans to increase distribution to 1.2 million over the next decade [12
]. However, it is not clear what the environmental and economic implications of these technologies would be and how they would affect the sustainability of the sector in the future.
In an attempt to provide an insight into this subject, this study uses life cycle assessment (LCA) and economic analysis to evaluate the environmental and cost implications of the current and possible future household cooking sector in Nigeria. As far as we are aware, this is the first study of its kind for the household cooking sector in Nigeria.
4. Conclusions and Policy Recommendations
This paper has considered the potential environmental impacts and costs in the household cooking sector in Nigeria up to the year 2030. The results suggest that both the impacts and costs would increase significantly if the heat demand continued to grow at the current rates. In particular, if business as usual continues, the life cycle environmental impacts will increase by three to four times, and the costs will be higher by four to five times by 2030. This is mainly due to the consumption of fuel wood rising by four times. This will also exacerbate the already high impacts on human health from indoor air pollution, which could increase the death toll by four-fold, from 79,000 in the base year to 316,000 in 2030.
Thus there is a clear need to chart a new course for the future household cooking sector in Nigeria. This includes improving the efficiency of the biomass economy and promoting other cooking technologies. This would also help to reduce the huge pressure on biomass reserves, the consumption of which is expected to reach 437 million tonnes by 2030 at the current consumption trends. The government has already drawn up plans to introduce improved fuel wood and solar stoves in Nigeria, which has been considered in this research, in addition to the BAU trends. It is also possible that other factors, such as high economic growth, greater availability and affordability of other fuels, could result in a shift towards a more fossil fuel-based trajectory where consumers move up the energy ladder. These possible trends have also been analysed in this study.
The results from these different pathways show mixed results. The analysis of the government’s plans to introduce improved fuel wood and solar stoves (GI scenario) shows that there would be no environmental advantages over the current system. This is because the number of stoves proposed by the government is far too low (~1.2 million by 2030) to bring about the significant reduction in the environmental impacts needed for this sector. As shown in the FI scenario, the number of the advanced stoves would have to be at least 30 times higher than planned to have a noticeable effect; however, while some impacts would be reduced relative to BAU, including the global warming potential (7%), acidification and eutrophication (~30%), some other impacts would go up significantly, notably human toxicity along the supply chain (35%). At the same time, the number of deaths from indoor air pollution would be two times lower than in BAU.
If, on the other hand, fossil fuel stoves (LPG and kerosene) are favoured, as defined in HEG 1, some environmental impacts would decrease relative to BAU (acidification and eutrophication) but the global warming potential, resource depletion, human toxicity and ozone layer depletion would increase significantly (50%–70%). The increased use of electrical and improved fuel wood stoves, as considered in HEG 2, would yield similar results as the fossil fuel based scenario but with a somewhat lower increase in the global warming potential (~40%) and a lower ozone layer depletion than in BAU (2%).
Furthermore, it is important to emphasise that, in addition to reducing the environmental impacts, the pressure on biomass and indoor pollution are reduced in all the scenarios except in BAU. This is critical in view of the fact that deforestation, soil depletion and indoor air pollution have an immediate impact on the wellbeing of rural communities in Nigeria. Furthermore, as shown in this work, unsustainable use of biomass could increase the global warming potential from the cooking sector by a factor of 10. Hence, sustainable development to reduce the rate of biomass consumption and increase reforestation in the medium- to long-term future is essential, requiring a concerted action of a range of institutions in Nigeria, including those in the energy, forestry, agriculture and health sectors. In the end, the effectiveness of the Nigerian biomass programme will be measured against the twin objectives of how well it has led to improvements in access to clean and reliable cooking fuels and how it has contributed to the enhancement of the biomass stock in the country.
On the question of costs, the FI scenario appears to be the least costly pathway to pursue with a unit heat cost of 1.32 $cents/MJ in 2030, compared to 1.74 $cents/MJ for BAU. However, its capital costs are around three times higher than for BAU. Nevertheless, there is the added dimension of creating more employment if the FI path is followed, given the labour intensive nature of the activities where much of the value added balance remains at the local level. However, this pathway may require high levels of organisation and institutional coordination to establish the advanced stoves market and ensure the necessary quality controls are in place. The HEG 1 and HEG 2 scenarios are more costly (2.78 and 1.79 $cents/MJ, respectively), mainly because of the high costs of the appliances and fuels. The GI scenario is comparable to BAU but, as discussed above, it does not offer any environmental advantages over the BAU.
In conclusion, the following policy recommendations are made based on the findings of this research:
It is evident that biomass will still be a dominant fuel in the household cooking sector in the long run. Thus, developing a sustainable development plan to protect forests and replenish biomass resources should be a priority for the Nigerian government; this would also help to reduce GHG emissions from the sector.
Advanced cooking technologies, such as improved fuel wood and solar stoves, would help towards addressing this issue and should be introduced by the government as soon as possible. However, the number of stoves needs to be increased significantly from that currently planned if some of the key environmental and health impacts from air pollution are to be reduced. Care should be taken to consider carefully the environmental impacts that would increase through such an intervention, particularly human toxicity along the supply chain, so that direct human health impacts from indoor air pollution are not reduced at the expense of health impacts elsewhere in the supply chain.
Introducing the advanced stoves will require government subsidies as most people will not be able to afford them. These should be aimed at helping those below the poverty line, particularly in rural communities. Robust mechanisms should be put in place to minimise the potential for corruption.
Introducing LPG and electricity stoves could help to reduce the pressure on biomass as well as health impacts from indoor pollution but would lead to an increase in climate change impacts and abiotic resource depletion. Therefore, this option should be considered carefully, as there are significant environmental as well as economic trade-offs.
Ultimately, the main goal for the government should be alleviation of poverty, as this would increase energy affordability, enabling people to move up the energy ladder and use more efficient appliances. This would in turn help to reduce the environmental and health impacts in this sector while at the same time improving access to clean cooking fuels and reducing pressures on national biomass reserves.