When does electrification work in rural Zambia?

Access to electricity is at the heart of the development agenda: Sustainable Development Goal 7 prioritises “access to affordable, reliable, sustainable and modern energy for all”. Indeed, a strong positive correlation between energy access and income per capita has motivated large-scale expansions of electric grids across low-income countries over the past two decades.

Zambia’s Rural Electrification Master Plan

In 2008, Zambia’s Rural Electrification Authority (REA) adopted their own country-wide rural electrification agenda: the Rural Electrification Master Plan (REMP). The plan aimed to increase access to electrification from 3% to 51% by 2030 through a combination of national grid expansion and off-grid projects. 

Although it will likely fall short of its initial 51% electrification objective, the REMP can still be considered a success. Hundreds of locations throughout Zambia's vast land mass have already received grid access (Figure 1). 

Figure 1: Electrification in Zambia, 2005-2020

Tracking the implementation of Zambia’s REMP

To study electrification and produce an accurate picture of its progress, high-quality geo-identified data at the village level is required for the entire country. In a recent IGC project, we exploit a common feature in modern rural electrification programmes – public infrastructure (such as schools) in a given location must be connected to the grid whenever the grid reaches that location. Therefore, we use administrative data reported by public school headmasters to the Ministry of General Education to track the arrival of the electric grid across schools in rural Zambia. 

Using this data, we can evaluate the country-wide implementation of Zambia’s REMP at an annual frequency from 2008 to 2020. This involves comparing electricity adoption and other development outcomes across 1,200 villages that were supposed to be electrified over the duration of the REMP. 

Zambia’s electricity adoption puzzle

Our study finds that the average effect of electrification on electricity adoption and usage is modest at best. This echoes the insights from the IGC’s research in Rwanda, which shows that up to ten years after grid arrival, only 51% of households in electrified communities are connected to it.

Interestingly, we can show that rural villages in Zambia experience the arrival of the grid in fundamentally different ways. In fact, the modest average adoption rate disguises stark differences in adoption rates between villages.

We find that most villages electrified under the REMP fall into one of two categories: close to zero or almost full electricity adoption. Essentially, grid extension to a rural Zambian village either has a massive impact on electricity adoption or virtually none.

This bimodal distribution of adoption across connected villages points to an important hurdle faced by households and businesses wanting to receive electricity: the ‘last mile problem’ of electrification. Once the grid has arrived in a village (that is, the medium-voltage network is extended and a transformer installed), any end users – except for public infrastructure such as schools and health facilities – must still pay a significant cost to connect. 

Therefore, the village faces a coordination problem in terms of who should pay for the low-voltage poles, overhead lines, and service drops to deliver electricity to all interested end-users. The cost for this 'last mile' will often exceed the annual income of any single rural household in a given village. 

The ‘last mile problem’ persists across sub-Saharan Africa

In Zambia, some villages have managed to overcome the ‘last mile problem’ by investing in a network of poles and lines to enable households and businesses to connect. Once the ‘last mile’ is in place, many end-user connections follow. Figure 2 shows households that have connected after the grid has arrived. 

Figure 2: Village (above) and household connections (below) in rural Zambia

Beyond Zambia, we notice this adoption puzzle of rural electrification in 18 of 24 Sub-Saharan African countries for which we have data. As in Zambia, connected villages either have almost full or very low electricity adoption (Figure 3).

Figure 3: Household grid connections in electrified locations 

In light of this evidence, it seems crucial to identify what drives high electricity adoption in some villages and contributes to its absence in others. Understanding how some villages manage to overcome the 'last mile problem', whereas others do not, can also help inform future rural electrification planning.

Productive uses drive successful electrification 

Our study shows that the existence of productive uses is the primary driver of successful electrification. Villages with pre-existing productive uses of electricity display almost full adoption after grid arrival. Additionally, we see large nighttime luminosity responses and positive development effects in these locations, including structural transformation away from agriculture (especially for women), new small-scale businesses entering, and in-migration. These villages also grow in terms of the number of buildings, corroborating their increased attraction and overall economic growth.

In Zambia, the most common productive uses are typically small-scale grain mills (chigayo in Nyanja), with millers seeking to transition from diesel to electric power. Anecdotally, these mills report dramatic cost savings of up to 80% when switching to grid electricity. Given their strong incentive to connect, these mills seem to play a significant role in organising village-wide electricity adoption and overcoming the ‘last mile problem’.

Figure 4: Zambian small-scale electric (left) and diesel grain mills (right)

Policy insights for rural electrification planning

Given the importance of productive uses for successful electrification, our study offers three key insights for policymakers across sub-Saharan Africa:

1. Prioritising villages with pre-existing productive uses when planning electrification can maximise the development impact of grid expansion.
2. When extending the grid to villages without productive uses, complementary investments in the local low-voltage infrastructure should be considered to overcome the ‘last mile problem’ and attract productive uses.
3. When extending the grid to remote locations, which are unlikely to support productive uses, consider off-grid solutions that enable at least minimal electricity access even in remote and sparsely populated areas.

Learn about our work in Zambia