Mechanical Technology

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22 Mechanical Technology — September 2015
⎪ Sustainable energy and energy management ⎪
The current power constraints
facing South Africa and Africa
have resulted in companies
being requested to cut their
power consumption by at least 10% in
order to alleviate the pressure on the
overburdened transmission and distribu‑
tion infrastructure. This appeal will, of
necessity, result in companies seeking
alternative power sources to accommo‑
date their energy requirements shortfall.
However, cautions Craig Bouwer, sales
engineer at Zest WEG Group’s Generator
Set Division, there is an apparent lack of
Bradley van der Spreng, project engineer and Craig Bouwer, sales engineer
at Zest WEG Group’s Generator Set Division talk about the importance
of carefully considering the company’s overall power requirements before
deciding on a backup power solution to accommodate a shortfall.
Bradley van der Spreng, project engineer and Craig
Bouwer, sales engineer at Zest WEG Group’s Generator
Set Division.
The containerised generator sets for
Liqhobong Diamond Mine in Lesotho incorporate a
collapsible snow roof which, when deployed on site, prevents the
build-up of snow and subsequent blocking of louvres.
A view inside a containerised generator
set from Zest WEG Group’s Generator Set
Division.
Selecting the optimum generator set
understanding of the many issues sur‑
rounding standby power. “Companies are
generally unaware of how to assess the
standby power requirements of a facility
or building. By implication, this suggests
that companies are also often unaware
of what the optimal solution for a given
application should be.”
A standby power solution is an im‑
portant capex decision that needs to be
considered carefully in terms of the com‑
pany’s overall requirements. Moreover,
the supplier needs to have the necessary
technical expertise and relevant experi‑
ence to offer a customised solution. A key
consideration for a standby power solu‑
tion is to understand the environment in
which the generator set has to function.
Original equipment manufacturer Zest
WEG Group’s Generator Set Division
has a dedicated facility in Cape Town
and offers generator sets ranging from
20 kVA units up to 250 kVA as off-the-
shelf products and 300 to 2 000 kVA
individual customised units as well as
multiple sets are available to achieve
turnkey solutions in excess of 12 MVA for
large-scale applications or projects. The
company has supplied a large number of
bespoke generator set solutions based on
the specific application and environment
in which they operate.
“A couple of recent examples include
the containerised three-generator unit
we designed and manufactured for DRA
Minerals’ Liqhobong Diamond Mine in
Lesotho and a turnkey power station for
AVI Group’s Indigo Brands. At Liqhobong,
we designed a generator set container
with a collapsible snow roof. When
the roof is collapsed it facilitates easy
transportation and, once deployed on
site, prevents the build-up of snow on
top of the container and the subsequent
blocking of the louvres,” says Bradley van
der Spreng, project engineer, Zest WEG
Group’s Generator Set Division.
The scope of supply on the Indigo
Brands project comprises three
1 000 kVA generator sets and three
1 000 kVA transformers. “What makes
this project unique is that Zest WEG
Group’s Generator Set Division is design‑
ing a custom built distribution system
and electrical panel for synchronisation.
The company is also supplying a 23 000
litre bulk fuel storage system to support
this installation,” adds van der Spreng.
The successful implementation of
these projects hinges on the company’s
ability to determine potential solutions for
the customer. Amongst these are consid‑
erations for sound restructuring methods,
fuel systems, electrical reticulation and
interfacing, the load and the duration
that this load is required to be powered.
“The type of load and the total power
drawn should be measured by a qualified
team from the generator supplier prior
to recommending a particular diesel
generator set. Following this, accurate
load calculations can be carried out and
a suitable system recommended. We look
at the entire electrical infrastructure and