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

foundations and is associated with lower levels of noise than driven piling.
The gas turbines, however, will be built in a noise reducing enclosure, with
the outside target noise reaching a maximum of 85 dBA at 1 m. In addition,
the following will be used to reduce noise as a result of the Project:
• Gas turbine filter and ventilation apertures are to be fitted with silencers,
and designed such that they face towards the existing plant, or towards
new plant such that all sensitive receptors benefit from screening.
• High performance silencers will be used and will be tuned to attenuate
low frequencies from the gas turbine exhausts.
• Azura’s design ensures that reverberant sound from the gas turbine is
minimised internally, for instance by using an acoustic enclosure. A
Hushclad double-skin enclosure will be used with good door seals which
will be replaced regularly to meet the specifications for 82 dB at 1 m from
the source. If the 82 dBA for the enclosure is not feasible with these
measures, then the turbine building will be upgraded to heavier walls or
more internal absorption or a concrete block wall to achieve the same
result. All plant items will be controlled to minimise noise of an impulsive
or tonal nature, such that the rating level as defined in British Standard
(BS) 4142: 1997 is equal to the specific noise level.
• Exhaust stacks will be designed to meet a power level of 92 dB(A).
• Azura’s design shall ensure that all walls, roof, windows and doors to the
building have a high noise reduction rating and ensure that there are no
significant gaps. Air conditioning/air flow requirements shall be
designed to take account of noise breakout. Low noise air coolers will be
used.
• Azura Power will further refine the noise modeling of the plant to avoid >
45 dB at the four farms to the west of the plant by implementing design
measures such as attenuators on the stacks, cladding on the turbine
building and/ or noise barriers at the four receptors.
The results of the noise modelling study undertaken as part of the EIA are
presented in Chapter 7.
Heat Emissions
The new and clean heat rate of the General Electric Frame 9E machine is
10,100 Btu/kWh. The heat emissions will chiefly originate from the stacks at a
heat transfer rate of approximately 820 GJ an hour and some additional heat
emissions from the fin fan cooler.
AZURA EDO IPP
3-12
DRAFT EIA REPORT