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BETHEL, ALASKA

 

“Feasibility study for a new 90MW generating facility”

 

 

Project Description

PES was engaged for an in-depth feasibility study for the development of a new 90MW generating facility in the remote community of Bethel, Alaska; either oil-fired combustion turbines or coal-fired. The study scope encompassed projected costs of engineering, equipment, construction, infrastructure requirements, fuel availability and logistics, and identifying viable opportunities for district heating. Due to the relatively long difficult winters, access to the community and thus delivery of fuel is sharply limited to a narrow time window necessitating particular focus on the logistics of fuel transport, unloading, storage, and reclaim.

If coal-fired, the facility would require in excess of 300,000 tons of coal annually to operate; presenting numerous technical challenges to be investigated and resolved. Such challenges included the determination of optimal coal characteristics for environment conditions, cost-effective transport/handling systems, bulk storage facilities, and reclaim methods. Further key issues to be addressed included sustained very low winter temperatures, snow contamination, fugitive dust emissions from handling, and the risk of in-pile auto-ignition of the fuel. At the end of a comprehensive investigative and engineering effort, PES recommended a purpose-designed barge transport and high-throughput unloading system for delivery, a bucket-style stacker/reclaimer, and covered bulk storage facility.

The fuel oil-fired combustion turbine facility option, operating in combined cycle, was relatively straightforward compared to the coal-fired option but presented its own specific challenges. Appropriate methods and technologies for handling and storage of fuel oils in extremely low temperatures, while difficult, are well-established within the Alaska petroleum industries. Similarly, suitable provisions for the operation and maintenance of combustion turbines in very cold environments were thoroughly investigated and those suitable for this application identified. PES recommended a plant configuration based on series of well-proven design elements with proven operational reliability in harsh environments and favorable economic life-cycle costs. For both options, modular plants adapted for installation on barges were evaluated and basic designs developed and compared to more conventional shore-based construction. The barge-mounted modular plant configurations were recommended on basis of

For both options, modular plants adapted for installation on barges were evaluated and basic designs developed and compared to more conventional shore-based construction. The barge-mounted modular plant configurations were recommended on basis of a cost savings for constructing a plant in the harsh conditions present in Bethel.

A detailed investigation was also undertaken to develop opportunities to serve the nearby Bethel community with district heating as both a revenue stream and as a public service. PES further identified a potential benefit to the project in that the district heating concept substantially reduced the need for large cooling towers or ponds during the colder months.

 

 

 

Project Details

Client City of Bethel
Date 2008
Services Feasibility study- projected costs of engineering, equipment, construction, infrastructure requirements, fuel availability & logistics
Location Bethel, Alaska

 

Project Features

 

PES identified the potential benefit of installing a district heating to reduce the need for large cooling towers or ponds during the colder months.

 

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