Two new 140MW gas-fired cogeneration units in Western Australia
were the latest projects delivered through GHD’s long relationship
with leading energy infrastructure company Alinta.
The cogeneration plants deliver more than 75 percent energy
efficiency, compared with 25-50 per cent for other power plants
operating in Western Australia. The recently completed cogeneration
units are located within Alcoa’s Pinjarra Alumina refinery in the
south-west of Western Australia. The combined output of the units
is 280MW of power, and up to 840tph of steam.
Cogeneration is the simultaneous production of electricity and
heat. The heat that may otherwise be wasted in the production of
electricity is captured and utilised to produce steam, which may be
used for both industrial and domestic purposes. At Pinjarra the
high pressure steam is first used to produce yet more power in the
Alcoa steam turbines, before being passed out to the Alumina
refinery process. Utilisation of waste heat in this manner also
reduces the requirement for cooling water supplies for power
generation and eliminates the need for structures such as the
cooling towers that dominate the skyline in a conventional power
plant.
Says GHD’s Ken Strain, “Energy efficient power generation has
always been one of our goals, and cogeneration plants deliver this
sustainable outcome. GHD has an enviable track record in
cogeneration and sustainable energy projects”.
Alinta engaged GHD to undertake concept design for
the cogeneration facility, prepare a feasibility study, develop
plant specifications, perform bid evaluation conduct contract
negotiation and develop a long term service agreement
specification. GHD also reviewed the facility design, construction,
commissioning and testing. To enable seamless integration of the
new unit, GHD undertook design, procurement and construction
management of the interconnection with the existing facilities.
The completion of the units represents the culmination of many
years of effort by Alinta, Alcoa and GHD. In fact, GHD undertook
initial concept studies for Alcoa more than 10 years ago. This
initial study formed the basis for the eventual realisation of the
project. .
GHD’s strong relationship with Alinta continued with GHD
providing Owner’s Engineer and detail design services for the 200MW
combined cycle Tamar Valley Power Station near Launceston in
Tasmania. The project, originally conceived by Alinta and due for
completion in August 2009, is now owned by Aurora Energy.