The cost of electrifying all households in 40 Sub-Saharan African countries by 2030

Electrifying sub-Saharan Africa (SSA) requires major investments and policy intervention. Existing analyses focus on the levelized cost of electricity at aggregate levels, leaving the feasibility and affordability of reaching Sustainable Development Goal #7 - access to affordable, reliable, sustainable and modern energy for all - by country unclear. Here, we use the electrification model OnSSET to estimate granular and spatially explicit levelized costs of electricity and costs per person per day (pp/d) for 40 countries in SSA. We find that solar-powered mini-grids and standalone systems drastically lower the cost of electrifying remote and high-cost areas, particularly for lower tiers of electrification. On average, least-cost electrification in SSA at Tier 3 (ca. 365 kWh/household/year), can be provided at 14c USD/kWh or 7c USD pp/d. These results are sensitive to demand assumptions, for example, misguided electrification planning or oversizing due to overestimated demand can lead to substantial cost increases. Our results highlight large variances within countries, which we propose to visualise using electrification cost curves by country. Policymakers should consider such cost curves and use a tailored approach by country and region to reach SDG7 in SSA.

The gut microbiome and early-life growth in a population with high prevalence of stunting

Stunting affects one-in-five children globally and is associated with greater infectious morbidity, mortality and neurodevelopmental deficits. Recent evidence suggests that the early-life gut microbiome affects child growth through immune, metabolic and endocrine pathways. Using whole metagenomic sequencing, we map the assembly of the gut microbiome in 335 children from rural Zimbabwe from 1-18 months of age who were enrolled in the Sanitation, Hygiene, Infant Nutrition Efficacy Trial (SHINE; NCT01824940), a randomized trial of improved water, sanitation and hygiene (WASH) and infant and young child feeding (IYCF). Here, we show that the early-life gut microbiome undergoes programmed assembly that is unresponsive to the randomized interventions intended to improve linear growth. However, maternal HIV infection is associated with over-diversification and over-maturity of the early-life gut microbiome in their uninfected children, in addition to reduced abundance of Bifidobacterium species. Using machine learning models (XGBoost), we show that taxonomic microbiome features are poorly predictive of child growth, however functional metagenomic features, particularly B-vitamin and nucleotide biosynthesis pathways, moderately predict both attained linear and ponderal growth and growth velocity. New approaches targeting the gut microbiome in early childhood may complement efforts to combat child undernutrition.