The Civil Engineering Contractor February 2019 | Page 41

confined to verifying that the
national plans meet the agreed
SAPP planning criteria and to note
the trading bottlenecks. Subsequent
regional integration scenarios then
remove the bottlenecks to facilitate
trading of surpluses. The objective is
to identify a least-cost development
path that balances investments,
losses, O&M, and cost of supply
interruptions. Because
both
technical and economic criteria are
considered, some unserved energy
is allowed if that is more economic
than eliminating it.
In the absence of information on
hydropower plants, generic models
were used, although this is not
altogether satisfactory, as hydro-
plant characteristics are very much
site-specific depending on inertia
of machines, head, and waterways.
The PP study has indicated that
Angola and Malawi should be
integrated into SAPP early on.
The following interconnections are
therefore clearly recommended for
early development:
• 
N’Zeto/Angola – Inga/DR
Congo
• 
Cahama/Angola – Kunene/
Namibia, possibly via Baynes
if a decision to implement this
project is firmed up
• M atambo/Mozambique
–
Phombeya/Malawi.
Electricity will be supplied to the
regional power pool through existing
projects, such as the Zizabona
interconnector project, which will
link Zimbabwe, Botswana, Zambia,
and Namibia; the interconnector
that will connect Angola to the
southern Africa power pool; the
Mozisa transmission line between
Mozambique, Zimbabwe, and
South Africa; and the transmission
interconnector between Botswana
and South Africa.
The addition of Batoka by 2023
can be supported by existing and
already committed transmission
projects. When Mphanda Nkuwa
is added in 2028 (in Component
C), the STE Project (backbone
transmission) in Mozambique will
have to be in place. The existing
www.civilsonline.co.za
Motraco system linking South
Africa and the southern part of
the grid in Mozambique along with
the existing DC link from Songo
to Apollo and also the link from
Songo to Zimbabwe, would provide
adequate capacity for trade with
other SAPP members for some
time once the STE backbone grid
is in place. The STE grid therefore
provides additional capacity for
regional trade.
The largest hydropower project by
far is Inga, which is also the most
remote from the centres of demand
that it has the potential to serve.
The development of Inga therefore
needs to be supported by major
transmission line projects.
On the generation side, the
SAPP member states commissioned
4 180MW of additional generating
capacity from new projects and the
rehabilitation of old power plants.
These projects were in Angola
(780MW); Malawi (10MW);
Mozambique (175MW); Namibia
(15MW); South Africa (2 550MW);
Tanzania
(150MW);
Zambia
(300MW); and Zimbabwe (200MW).
These projects were commissioned by
both public utilities and independent
power producers.
The generation mix for the new
power plants commissioned in 2016
came from hydro (43%), gas (24%),
solar (11%), wind (10%), coal (7%),
and diesel (5%).
At end-April 2017, the member
states had an installed generation
capacity of 59 539MW and operating
capacity of 54 397MW against a
demand and reserve requirement of
53 478MW.
In conclusion
Robinson noted that the satisfying
finding of the study is that it shows
that the imposition of the ‘realism’
constraints on the idealised Full
Integration Case involves only
a limited cost, which does not
significantly dilute the benefits of
regional power sector integration.
At the individual country level, the
least-cost regional plan allows the
countries to fulfil the SAPP security
BUSINESS INTEL
The focus of The SAPP Plan is to
integrate interconnections.
and reliability criterion through a
combination of local generation and
firm imports.
Another important finding that
emerges, he noted, is that the cost
of transmission interconnectors is
only a small fraction of the generation
investment costs. On an NPV basis,
in Component C, investment costs
are only USD3.3-billion out of total
investment of USD121-billion, or less
than 3%.
The executive summary stated: “There
is thus a strong case to prioritise regional
interconnector investments, which create
opportunities for flexible responses to
the out-turn of uncertainties, as well
as generally making an important
contribution to strengthening national
transmission grids.”
For the region as a whole, the
PP offers significant cost savings
and reduced CO 2 emissions: some
countries will inevitably benefit more
than others: Mozambique and the
DRC will become major exporters
of power, this being a new source of
foreign exchange earnings; and as the
biggest importer, South Africa will
be a major beneficiary of low-cost
hydropower energy being available.
There is a more complex picture for
other countries. nn
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