HomeMy WebLinkAboutCity of Unalaska - Powerhouse Renovation Project Summary - DE-FC07-99ID13825 - March 2011 1
Power House Expansion Project Summary
March 22, 2011
The City of Unalaska’s Powerhouse Renovation Project consisted of building a
16,620 square foot facility to house an electrical generation capacity of 20.8 MW.
This project was completed in four phases:
Phase I consisted of the purchase of the two 2 Wärtsilä engines;
Phase 2 was the PCB remediation on the construction site;
Phase 3 was the Site Demolition and Civil Work;
Phase 4 was the New Powerhouse Building construction and the
installation of the two Wärtsilä 12V32 Generator Sets and
accompanying auxiliary equipment.
Following is a summary of tasks completed during the construction of Phase I-4.
Phase 1:
During 2003-2004, the City of Unalaska completed the preliminary design of the
New Powerhouse and researched the various generator options. After extensive
study, the City purchased two Wärtsilä engines on June 23, 2004. Following the
engine selection, the design team worked with Wärtsilä in 2005-2006 to complete
the final design of the New Powerhouse building.
Phase 2:
During the final site selection process, soil testing determined that there was a
small amount of PCB contamination on the most preferred site. The preliminary
cost estimate for clean up showed that even after clean up of the PCBs, the site
provided the best location for the facility at the best value.
The clean up project was bid and work began in April of 2007. Unfortunately the
extent of the contamination far exceeded the preliminary estimates and work
continued through April of 2008.
Phase 3:
Because of the extensive PCB contamination and known diesel contaminated
soil on site, the City elected to separate the overall construction project into 2
contracts – the site demolition/civil site work and the building construction. The
site demolition contract began in July 2008 and continued through May 2009.
Work included demolition of the existing ancillary structures, removal of
contaminated diesel material, excavation and placement of structural fill to final
grade.
Phase 4:
Construction bids were solicited in October 2008 and SKW Eskimos, Inc., the
lowest bidder, was awarded the contract. Bonds were sold, and the notice to
proceed was issued on January 23, 2009. With that, the permitting process
2
began, and the environmental air permit application was sent to ADEC. As the
first year came to a close, the electrical conduit was installed, the concrete slab
was poured, and the metal frame for the building was erected. The Wärtsilä
engines and the Black Start generator sets all arrived in Unalaska.
As we entered the second year, the building was completed and mechanical
piping installation began. The City’s Power House employees were sent out for
several weeks of training with Wärtsilä in preparation for operating the new
engines. The Wärtsilä and Black Start generator sets were placed in the new
building, and Wärtsilä engine stacks and silencers were installed. The cooling
water fans footings were poured, the control room sound insulation was installed,
and batteries and accompanying equipment were installed. As the second year
came to a close, concrete work for the transformer pads was completed, the
cooling water fans and T-5 transformer were installed, and the cooling water,
fuel, lube oil, and air piping were installed. All high voltage electrical lines and all
medium voltage lines were pulled. The Switch Gear medium and high voltage
lines were terminated, and the cutover plan was completed by the end of the
second year. The air quality permit was at its 30-day public review.
Early in the third year, a great deal of work was completed, including the
following: equipment communication wire and all other electrical wire
terminations; Wärtsilä SCADA and communications tests; switch gear and relay
settings and testing; phasing on all electrical equipment; rotation inspection on all
motors; installation of control room equipment; movement of T4 and T11
transformers; commissioning of all secondary equipment; commissioning of
engines and generators; performance testing of the generator sets; and painting
of the floor. The ADEC air permit was granted, and Phase 4 of the new Power
House was completed and turned over to the City of Unalaska. In the last few
months, the emissions source testing has been completed, and the contractor
has completed the punch list.
The new Power House has been officially in service since December 17, 2010
and has produced over 4,500,000 kWh of electrical energy with an average
efficiency of 16.0 kW per gallon of fuel. This increase of fuel efficiency from 14.5
has drastically reduced the cost of electrical generation through fuel savings and
in turn reduced our carbon foot print. The City of Unalaska is proud to have
partnered with the Alaska Energy Authority on a project that accomplished these
results.