POWER September 2013 - 42

TOP PLANTS
1. Ready to roll. The plant is arranged into three banks of six engines, all of which can
operate independently of each other, as needed. Courtesy: Wärtsilä
into its project manual. Wärtsilä and its
subcontractors were fully committed to
on-site safety, and extensive instruction
and training were conducted to ensure an
injury-free workplace.
Communication and interaction with the
local community was key to ensure that all
stakeholders would benefit from the project.
This required a good understanding of the local
labor laws and regulations.
Wärtsilä employed as much manpower
from the Sasolburg area during the project
as possible. Total manpower peaked at
750, 70% of whom were local employees.
Because labor unrest is unfortunately fairly
common in South Africa, Wärtsilä employed
an industrial relations officer, who
conducted weekly meetings with contractors
and labor unions, and reported to Sasol
and the South African Department of Labour.
This commitment resulted in a good
relationship with the unions and a strikefree
project.
2. Flex-time. The modular nature of the
plant means enhanced flexibility and efficiency.
Courtesy: Wartsilla
meant scaling up the output would still deliver
a highly standardized product. The
plant was ordered as a turnkey project,
with Wärtsilä performing all engineering,
procurement, and construction, as well as
supplying all electrical and mechanical
equipment.
The project schedule was one of SNE's
Table 1. Project timeline. Source:
SNE
Milestone
Groundbreaking
Foundation poured
Gensets delivered
Plant building completed
First engine start
First sync to grid
Performance tests
Project complete and handover
Date
Sept. 2011
Oct. 2011
April-July 2012
June 2012
Nov. 2, 2012
Nov. 15, 2012
Dec. 10, 2012
Dec. 14, 2012
altitude, and its closed-loop cooling system
means water requirements are minimal. Individual
engines can be brought online or
shut down as needed, meaning the plant can
operate at peak efficiency across its entire
output range.
What Sasol wanted would be the largest
gas engine plant ever built in Africa and
the first in South Africa, but the modular
nature of a project built around the 34SG
42
primary concerns. A fast, on-time delivery
was important to support the overall project
because of the local electricity situation. A
firm, fast schedule was possible because of
the standardized nature of the power plant,
which allowed for the use of standard components
and modules that were purchased
from suppliers having preexisting agreements
with Wärtsilä.
The contract was signed in July 2011,
and Wärtsilä broke ground in September.
The first engine start was a little more
than a year later in November 2012, and
the 175-MW plant entered commercial operation
at the end of December, nine days
ahead of schedule. The facility was officially
inaugurated in a ceremony on July
10. Construction and commissioning lasted
15 months with a total of 1.4 million manhours
worked. Key project milestones are
given in Table 1.
Safety First
Sasol is well known throughout South
Africa for its high health, safety, and environmental
standards, and meeting those
standards was a key requirement. Wärtsilä
employed a dedicated safety and environmental
manager at an early stage of the
project to incorporate requirements set
by Sasol and South African regulations
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Meeting the Needs
The plant building is divided into three sections,
with each set of six engines having its
own exhaust stack (Figure 1). Currently, only
about half the output is used by Sasol's operations,
with the rest being sold to the national
grid. Though designed for simple-cycle operation,
provisions were made for adding a
heat recovery system and steam cycle at a
later date. Space has also been reserved for
adding additional gensets should the need
arise (Figure 2).
The new plant is operated and maintained
by Wärtsilä under a three-year agreement.
That agreement includes the training of local
employees of SNE.
" This plant is a significant milestone for
Sasol, as we begin to ease our load on the
national grid and contribute to our own energy
efficiency targets, " said Sasol Senior
Group Executive Lean Strauss. " We are
proud of this new facility, which demonstrates
how we can add versatility to natural
gas. "
" This inauguration marks a significant
step forward for power generation based on
gas fuel, " Tony van Velzen, Wärtsilä's African
regional director said. " Never before has
a power plant of this size running exclusively
on gas engines been installed on the African
continent, and we see this as an important
achievement on the road to cleaner and more
efficient electricity production. We are proud
to have worked closely with Sasol to develop
this highly efficient and environmentally sustainable
facility. " ■
-Thomas W. Overton, JD is POWER's gas
technology editor. Follow Tom on Twitter
@thomas_overton.
POWER | September 2013
http://www.powermag.com
POWER September 2013

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