Azura-Edo Independent Power Plant Environmental Impact ... - IFC

• duration required for construction and maintenance activities in a
Nigerian context.
Based primarily on the operating efficiency of OCGT this technology was
selected for the proposed power plant. The price of the gas feed-stock was
also a determining factor.
3.1.6 Possible Future Conversion of OCGT to CCGT
The OCGT plant has been designed to accommodate the potential conversion
to CCGT with a total net output of approximately 670 MW. The gas turbines
exhausts and stacks have been orientated in such a way as to allow for the
Heat Recovery Steam Generators (HRSGs) to be built directly behind them.
The CCGT will form an extension adjacent to the OCGT facilities with HRSGs
installed next to each gas turbine.
The conversion of the plant to CCGT will require the construction and
installation of four heat recovery steam generators (HRSGs) which will be
connected to the exhaust of each of the existing four gas turbines. It will also
involve the installation of two steam turbine generators. This will create two
CCGT blocks (each a two plus one configuration) such that the gas turbine
and the steam turbine generators are of a similar size, and the transformers are
of a similar size so that they are interchangeable. The principle aim is to
capture excess exhaust heat of the OCGT engine, thus extracting more useful
energy from the fuel and thereby increasing the system's overall efficiency.
The construction of the CCGT plant will take place if and when it is deemed
that the plant conversion from OCGT to CCGT is economically viable.
Consequently, the CCGT plant is excluded from consideration in this EIA.
The environmental and social impacts resulting from the conversion of the
plant to a CCGT system have therefore not been considered within this EIA
and will be identified and assessed within a separate EIA, if required.
3.2 POWER PLANT
3.2.1 Overview of Power Plant Components
The key Project components are listed in Table 3.1.
Table 3.1
Key Project Components
Key Component
Gas Turbine Power House
Additional Information
Four Frame E gas turbines and generators each
with a nominal output of 112.5MW with stack
diverter/ damper units. The gas turbines have
incorporated Dry Low NO x burners.
AZURA EDO IPP
3-3
DRAFT EIA REPORT