Dr. Johanna Choumert-Nkolo

In 2016, only 33% of households in mainland Tanzania were connected to some form of electricity (17% in rural areas and 65% in urban areas) (The United Republic of Tanzania, 2017). These figures perfectly illustrate the energy challenges in Sub-Saharan Africa (SSA) where only 43% of the population (76% of the urban population) has access to electricity (World Development Indicators). Although, SSA has experienced an impressive increase in energy demand over the last decade, grid connection rates lag behind the rest of the globe with, notably, the supply side suffering from high connection charges and weak cost-recovery.

Closing the energy gap and ending energy poverty are explicit targets of the global agenda (e.g. Sustainable Development Goal 7, New Deal on Energy for Africa, Sustainable Energy for All,  and the Lighting Africa initiative) and will have multiple dividends on several development outcomes on health, financial inclusion, education, time use, economic welfare and mobility (Bos et al., 2018; Chaplin et al., 2017; Köhlin et al., 2015).

In our article “Stacking up the Ladder: A Panel Data Analysis of Tanzanian Household Energy Choices” published in World Development, co-written with Pascale Combes Motel (CERDI) and Leonard Le Roux (University of Cape Town), we develop an understanding of the nature of household energy use in Tanzania in the context of the energy ladder and stacking (fuel mixing) hypotheses.

Key contributions

  • We analyse the determinants of household cooking and lighting fuel choices using data from 3,088 households interviewed over three waves from 2008 to 2013 in the Tanzanian National Panel Survey.

  • We propose five ways of measuring fuel stacking to account for both direction and intensity of stacking behaviours.

  • We introduce electricity access using nighttime lights data.

  • Given the gender-differentiated impacts of fuel use, we investigate the relationships between intra-household bargaining and fuel choices.

 Some stylised facts

Most households present high levels of traditional fuel dependency, especially for cooking, and a particularly low level of reported reliance on electricity. There is also a significant level of spatial heterogeneity in dependence on both traditional lighting and cooking fuels, with the lowest rates found in Dar es Salaam (See Fig. 1 and Fig 2. where darker colours show a higher proportion of households relying on traditional fuels).


Expenditure data presented in Fig. 3 and Fig. 4 illustrate the notion of fuel stacking or mixing. The best-off households mainly cook with charcoal and mostly use modern lighting sources, but use a range of different fuels.


Main findings

  • Tanzanian households stack up the energy ladder. An increase in household socio-economic status, while associated with a transition towards modern fuels, is also associated with an increase of the variety of fuels purchased.

  • The propensity of households to transition to modern lighting fuels as incomes increase is much higher than that for cooking fuels.

  • Access to electricity alone does not secure a transition to modern fuels.

  • The level of education of the spouse as well as a composite index comprised of the level of education, age and labour market access of the spouse are positively correlated with a transition away from firewood and animal residue for cooking, towards charcoal, but also towards modern lighting fuels.

  • There are clear reasons why households may choose to engage in fuel stacking: irregularity of income flows, unreliable grid network, risks associated with dependence on only one fuel, and cultural aspects.

Policy implications

Can central and local authorities rely on prices to promote the energy transition to modern fuels? Our results show that the price responsiveness of households is greater for lighting fuels than cooking fuels. We find no significant own-price (and cross-price) effects on the choice of charcoal and firewood as the major cooking fuel. Our results partly support the idea that while fuel prices theoretically promote fuel shifts, this is unlikely when there are no alternatives.

Is fuel stacking desirable from a policy perspective? Consequences of fuel stacking may outweigh individual benefits. Reduction of household air pollution is likely to be modest in a fuel stacking context; and, fuel stacking can also deliver detrimental environmental outcomes owing to the deforestation pressure.

Should we give more weight to health arguments to implement energy policies? Household air pollution from the use of biomass fuels is a severe health issue, particularly for children. Public health arguments should thus play a wider role in energy policies.

How should the use of cleaner technologies be promoted, especially by the poorer households? Policies which help households in funding or accessing credit to purchase electric and gas stoves might be useful in encouraging the use of clean fuels for cooking.

Concluding remarks

Failure to address the effects of rapid population growth, urbanisation and economic growth on energy demand will have massive implications in terms of human development and environmental degradation, in Tanzania and SSA in general. Our results show that Tanzanian households slowly stack-up the energy ladder but also that higher incomes and access to electricity are insufficient conditions for a transition towards modern fuels. Future research should thus investigate the potential for off-grid energy solutions. Finally, the charcoal sector should be better understood given that it is not only a major source of energy, but also a major source of livelihood in Tanzania.

Note: This blog post gives the views of the author, and not the position of the EDI Group.

About the Author

Dr. Johanna Choumert-Nkolo is the Head of Research at EDI. Her publications are accessible here.