Page 16 - Apmor 2018

energy analysis

New Dams in Africa Could Add Risk

to Power Supplies Down the Line

By Declan Conway

n the 1980s and 1990s parts of Africa saw a plant. The dam will generate just
surge in dam building for energy production. under a quarter of the power
IAfter a brief hiatus there has been renewed generated by the world’s largest
interested. Many new construction projects hydropower station, the Three
are planned and underway across sub-Saharan Gorges Dam.
Africa. The new dams in Africa have
the potential to meet increased
electricity demand. But our
Hydropower represents a research into the links between
significant and rapidly expanding climate and the water, energy and
proportion of electricity production food nexus in Africa shows that in
in eastern and southern Africa. the longer term the locations of
Around 90% of national electricity the new planned dams could put
generation in Ethiopia, Malawi, the security of electricity supply at
Mozambique, Namibia and Zambia risk for large parts of southern and
eastern Africa. This is because the
comes from hydropower. The share majority of planned dams are in
of hydropower in sub-Saharan the same river basins and will rely
Africa, which accounts for 20% of on similar patterns of rainfall and
electricity production, is likely to hence be vulnerable at the same
grow rapidly. (If South Africa - which time to drought and dry years.
relies on coal powered electricity - This will create vulnerability
was excluded, this figure would be because a lack of rain and
much higher, but separate numbers droughts could lead to electricity
aren’t available.) supply being disrupted. This is why
it’s important to factor climate Declan Conway
variability and change into dam
An energy initiative, the Programme for design and management, and to
Infrastructure Development in Africa, that diversify the electricity production to avoid Without alternative power sources, fluctuations
has the buy in of all African countries, argues over reliance on hydropower. in hydropower can disrupt electricity supply.
for major hydropower developments within Reliance on hydro is very high And supply might need to be turned off either
a broader clean power agenda. The initiative to ration dwindling water resources or because
argues that this would enable African countries Hydropower relies on the flow of water to demand simply can’t be met.
to keep pace with rising demand for electricity. drive turbines for electricity generation. It
It estimates that total generating capacity, uses natural changes in elevation or artificial
which is presently 125 GW, will need to storage in reservoirs to take advantage of the
increase by 6% per year to 2040. water level difference. Drought or successive Our study shows that if all the
The large hydropower dams planned for dry years can result in not having enough water planned large dams are built, 70%
southern and eastern Africa for construction to drive electricity generating turbines and a of total hydropower generating
by 2030 could double the current installed shortage of electricity. capacity in eastern Africa will
capacity for hydropower taking it from 17 000 In countries like the US and in parts of Western depend on rain within the same
MW to 49 000 MW. They include a number Europe hydropower is complimented by other rainfall clusters by 2030. In southern
of new developments, such as the Grand power sources. This means that in times of Africa, 59% of hydropower
Ethiopian Renaissance Dam on the Blue Nile. drought other sources of power can balance
The Renaissance Dam on its own will have an the shortfall. But in countries where the energy generation will depend on a single
installed generating capacity of 6000MW. This mix is dominated by hydropower - as in sub- area of similar rainfall variability.
is similar in size to the world’s largest nuclear Saharan African countries, Norway, and Brazil
power station, Japan’s Kashiwazaki-Kariwa - climate variability is much more of a problem.

16 | AFRICAN POWER Mining & Oil Review Vol 21, Issue 20, 2017