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B. Generator at City Hall CITY OF CHANHASSEN 7700 Market Boulevard PO Box 147 Chanhassen, MN 55317 Administration Phone: 952,227,1100 Fax: 952,227.1110 Building Inspections Phone 952.227.1180 Fax: 952.227.1190 Engineering Phone: 952.227.1160 Fax: 952.227.1170 Finance Phone: 952.227.1140 Fax: 952,227.1110 Park & Recreation Phone: 952.227.1120 Fax: 952.227.1110 Recreation Center 2310 Coulter Boulevard Phone: 952.227.1400 Fax: 952.227.1404 Planning & Natural Resources Phone: 952.227.1130 Fax: 952.227.1110 Public Works 1591 Park Road Phone: 952.227.1300 Fax: 952.227.1310 Senior Center Phone: 952.227.1125 Fax: 952.227.1110 Web Site www.ci.chanhassen.mn.us B - To: Todd Gerhardt, City Manager ')JL Laurie Hokkanen, Assistant City ManagerlJ. Rick Rice, MIS Director From: Date: July 9,2008 ~( Re: Generator at City Hall BACKGROUND Over the past six months, staff has been examining the need for a generator at City Hall. This need is prompted by two main items, namely the need for back-up power for the servers, computers, and telephone system at City Hall and the designation of City Hall as the Emergency Operations Center. Staff has worked with Sheldon Sorensen at Barr Engineering to examine our needs and alternatives. By using our Xcel Energy bills, we have determined that the building historic demands are approximately 115kW (summer demand). It is typical to provide a 25% safety factor, so 115kW x 1.25 = 144kW. A 175 kW size generator is proposed, allowing for some future increase. The incremental cost between a 150 kW and 175 kW is not significant until you extend beyond 200 kW. Staff proposes that the generator be diesel powered. While the installed price for diesel vs. natural gas up to 200kW is about equivalent, there is a risk of losing natural gas service during a catastrophic event. There have been incidents where the natural gas company will turn off the gas supply to areas where buildings are blown down following extreme storms. Most of the City's standby generators on the water/wastewater system are diesel-powered. Staff proposes to locate the unit on the north side of the building, east of the entrance to the Building Department. The unit will require sound abatement features on the intake air and discharge air ducts in order to comply with MPCA noise rules. We will also screen the generator for aesthetics. By installing a generator, we will be able to participate in the Xcel Energy Demand Control Rate. This program allows Xcel to "kick the City off" of their power supply in times of,peak demand, at which point we would run City Hall off of the generator. Xcel estimates that we could save approximately $3,300 annually. However, the City will incur additional operating and maintenance costs, which will likely cut the savings in half (or more, depending on diesel prices). In order to maximize the use of this equipment, staff examined the possibility of a portable generator that could be stationed at City Hall but available for use at a well or lift station. However, to do so would require several changes - an increase to 250 kW to accommodate the power needs of the wells/lift station, a 3-voltage power supply, electrical wiring from the parking lot to the building, and some site work in the parking lot. These changes increase the price of the portable generator to almost double that of the stationary unit. Also, we would either not be able to take advantage of the Xcel rate The City 01 Chanhassen · A growing community with clean lakes, quality schools, a Charming downtown, thriving businesses, winding trails, and beautiful parks. A great place to live, work, and play. reduction program or be prepared to face penalties if the generator was not available when Xcel needed it. Thus, staff does not believe the portable generator to be a cost effective alternative. A breakdown of the projected costs is provided below. OPTION I-STATIONARY UNIT 175kW diesel engine-generator package with fuel tank, housing, noise abatement -- $45k Concrete pad, grounding, installation -- $10k l200A, NEMA 3R service entrance, metering and automatic transfer switch -- $30k Cable and conduit -- $25k Site work -- $10k Subtotal-- $120k Contingency (10%) -- $12k Subtotal -- $132k Engineering (15%) -- $20k OPTION 1 TOTAL BUDGET -- $152k OPTION 2 - PORTABLE UNIT 250kW diesel portable engine-generator package with fuel tank, housing, trailer, 3-voltage quick- change, cables and connectors -- $130k Concrete pad, parking area revisions, grounding -- $8k Outdoor pedestal with generator connectors -- $7k 1200A, NEMA 3R service entrance, metering and automatic transfer switch -- $30k Cable and conduit -- $45k Site work -- $8k Subtotal -- $228k Contingency (10%) -- $23k Subtotal -- $251k Engineering (15%) -- $37k OPTION 2 TOTAL BUDGET -- $288k The generator is a budgeted item for 2008. $130,000 was originally included in the CIP, however the fund can accommodate the estimated cost of $152,000 through under spending on other items. If the Council does not wish to proceed with this generator project, we will need to consider a smaller scale generator that is capable of providing back-up power for our computer equipment. We currently have battery back-up time that will provide 20 minutes for the computer systems to shut down (no desktop functionality during this time) and two hours of back-up for phone service. If the Council wishes to proceed, staff will begin obtaining quotes for the items listed in Option 1 and will place the approval of the project on a future Council agenda.