Small dams could help deliver electricity to much of Africa’s population, but since they lack the prestige of larger-scale projects, few of them get built.
Fewer than 10% of sub-Saharan Africans are connected to the electricity grid, and those people and institutions that do have power often depend heavily on dams. In addition, much of Africa is prone to droughts, which means that the sprawling dams that dominate the continent’s rivers rarely operate at full capacity. Writing in IEEE Spectrum, a magazine published by the Institute of Electrical and Electronics Engineers, G. Pascal Zachary says small- and micro-size dams represent a better approach to electrifying the continent than their larger cousins. The smaller dams, which can work with water from fast-moving streams and rivers, can provide electricity to remote areas and are simpler and less costly to construct. They have a smaller environmental impact and are easier to remove if a river runs dry or the dam severely disrupts local agriculture.
In Uganda, which has plenty of rivers and streams to supply power, Mr. Zachary describes how a small water-power generator, supplied by a small nearby dam, delivers 60 kilowatts of energy to a nearby hospital. The generator would barely be enough to run a single magnetic-resonance imaging machine, a staple in Western hospitals. But it does provide enough power to light the hospital and keep basic equipment running for the 100 nurses and doctors who work there. The entire generation system cost $15,000 to build.
Still, Africa’s leaders are unlikely to abandon their preference for big public works, says Mr. Zachary, since they create thousands of construction jobs and reinforce the political might of the central government. Why not build both big and small dams? Uganda’s president, Yoweri Kaguta Museveni, says big dams are crucial to solving the country’s power problems, but a top energy adviser to the government says a mix of both kinds of projects is on the horizon. – Robin Moroney