Page 18 - Respond 2019 Magazine

/ Future Climate for Africa

Changing rainfall

patterns spell risk for

hydropower in Africa

New research warns planned hydropower dams across
eastern and southern Africa are vulnerable to drought

Hydropower dams planned for eastern and hydropower accounts for over 90% of
southern Africa could put electricity supply national electricity generation in Ethiopia,
at risk for vast regions because they rely Malawi, Mozambique, Namibia and Zambia.
on the same rainfall patterns for electricity Rainfall variability, in the form of dry years
generation.
with little rainfall and wet years with more
This is the warning from new research rainfall, can be similar for several years at a
led by Professor Declan Conway from the time and is a characteristic feature of much
Grantham Research Institute on Climate of Africa’s climate.
Change and the Environment and the ESRC The researchers add that the problems of
Centre for Climate Change Economics and a changing climate are likely to exacerbate
Policy at the London School of Economics existing management challenges for
and Political Science, in collaboration hydropower and increase the threat of
with researchers at University College climate-related disruption in electricity
London, the University of Pretoria and the supply.
University of East Anglia.
Hydropower relies on the flow of water to
The study, which was published in the drive turbines for electricity generation.
journal Nature Energy on 8 December Drought or successive dry years could
2017, reveals that if all the large dams that result in lower volumes of water in
are currently planned are constructed, dams which are insufficient to drive
by 2030 70% of total hydropower electricity-generating turbines. Where
generating capacity in eastern Africa there is no alternative generating capacity,
will be dependent on areas with similar fluctuations in hydropower can disrupt
rainfall patterns. In southern Africa 59% electricity supply.
of hydropower generation will depend on
areas with similar variability in rainfall. Electricity utilities can be forced to turn off
supply to ration dwindling water resources
This significant dependence of hydropower to maintain intermittent electricity
generation on areas with the same generation or simply because they are
rainfall pattern means that within eastern unable to meet electricity demand.
and southern Africa the majority of
hydropower generation will be vulnerable The study points out past examples of
to the same dry periods and droughts, power outages due to the rainfall changes.
which could lead to electricity shortages Following dry conditions in much of
and power outages. southern Africa during the recent El Niño
event of 2015–16 Malawi, Tanzania, Zambia
This could pose a significant challenge and Zimbabwe all experienced electricity
for electricity security as hydropower is outages due in part to reduced rainfall.
heavily relied upon in Africa. For example,

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