Saturday, March 23, 2024

Renewable Power in Africa

Prospects for growth in electricity access and in clean energy.

Africa is an enormous continent, notoriously larger than China, the US, and Europe combined. Its population is also large- as large as that of India, at about 1.4 billion people. This population is growing rapidly, while its social and economic systems are developing more slowly. But as we know, the main ingredient of an advanced economy is power, which as traditionally been drawn from fossil fuels. Advanced economies are in the painful and reluctant process of transitioning away from fossil fuels. We can do a lot to help Africa to leapfrog this history by front-loading renewable energy.

There was a recent paper about the hydropower prospects in Africa. It notes that there are many projects on the drawing board, with many undammed rivers on the continent. But as we have learned in the US, the implications of river damming are quite destructive and wide-spread. For example fish ladders simply do not work- not at the scale needed to keep fish populations (and fisheries) healthy. Then there are problems of siltation, water temperature, erratic flows, and population displacement. There is a movement in the US to remove dams wherever possible, to free ecosystems back to a functional state. 

"More than 300 hydropower plants, corresponding to an additional 100-GW power capacity, are under consideration across the continent."

The article made the basic point that, given the state of other renewable power sources, and the prospect of lower water levels and droughts due to climate change, that roughly half of the planned hydropower projects they know of are economically inviable, even putting aside environmental considerations. 

This leads to the question of what to do instead? Maybe the answer is microgrids. In the developed world, it is increasingly common for people to take control of their own electricity production through the use of solar power. But at a single house level, power inputs and consumption are both erratic and require a lot of storage capacity to furnish a reliable system. The typical system is highly reliant on the larger grid to manage this intermittency. Microgrids occupy a middle range between grid-scale power, which is subject to problems of centralized political and social development, and the individual house, where the expense of managing fully independent electrical supply is highest.

The current grid in Africa, colored for >66 kV (dark blue) and the rest light blue. Note the patchy regional distribution, with lots of underserved areas. The US has a much denser grid. 

A map that suggests likely locations for smaller microgrids in Africa.

These maps note that there are many underserved areas in Africa- some concentrated urban areas, and a great spread of rural areas. Electrification is well-advanced in South Africa and the heart of West Africa. But there are many rural areas that would be better served by microgrids of various scales. Microgrids can be altered over time and integrated into larger systems. Their production and storage capacities are both beneficial for larger grid stability and scalability. Africa is, naturally, positioned ideally for solar power, and the Sahara is a natural location for massive power installations, to serve both Europe, the Middle East, and Africa.

A proposal to run a super-grid around much of Africa, to harness supplies from the Sahara, among other sources.

One of the main characteristics of renewable power is that it has high up-front costs. The fuel is free, and clean. But the mechanisms to capture and store it are expensive. Thus if we want to encourage a more rapid transition to sustainable power systems in Africa, we would help pay for the up front costs, sharing capital investment in the interests of everyone, both here and there. Africa is currently a big exporter of oil and gas. As other regions transition away from those fuels, it is imperative that this production not be redirected and propped up by further Western investment, but rather replaced with better energy sources.