2008 Minnesota Solar Tour
Saturday, October 4, 2008

Minnesota Renewable Energy Society (MRES)

www.MNSolarTour.org

Merrick, Inc.

3210 Labore Road

Vadnais Heights, MN 55110

Access to the solar array on the roof is up a steep interior stairway and through a roof-hatch. Direct viewing will be dependent on the weather and limited to those over the age of 21 with no ambulatory limitations or issues with vertigo. Those eligible and interested in going on the roof will need to sign a disclaimer form and must wear flat-soled shoes, slacks/shorts, and have sunglasses. We will have a PowerPoint presentation on the solar array installation in the lobby and people available to answer questions all day.

The largest solar array in Minnesota, Merrick Inc.'s 100 kW PV array powers the 52,000-square-foot building's 110-ton geothermal heat pump (GHP), which heats and cools the building year around. The 110-ton GHP system includes 108 vertical wells, filled with glycol antifreeze, 200 feet deep into the ground to capture heat in the winter or shed heat in the summer. The glycol is then pumped to 21 heat pumps inside the building to heat or cool the fresh air circulated throughout the facility. This GHP system is powered by electricity and the building uses no natural or propane gas and has no emissions to the atmosphere except for the fresh air exchangers. Merrick started the process in 2001 by greening the building with an R21 thermal envelope. The PV project began in early July 2008 with the installation of a new Durolast white roof, and the project was completed by Labor Day 2008.

Merrick is a nonprofit agency working to meet the employment, personal development, and transportation needs of adults with developmental disabilities. Clients work and volunteer with over 80 businesses throughout the entire Twin Cities, with rides provided by Merrick's transportation division.

Read more about Merrick, Inc., in the September 2008 issue of The Solar Flare.

System Components

Solar ElectricGround-Source Heat

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100 kW solar PV system with 525 panels

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110 ton geothermal heat pump (GHP) system

Additional Sustainable Features

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R21 thermal envelope

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Durolast white roof

Designer/Engineer

Energy Concepts

Installer

Steiner Plumbing & Electric

Date of Installation Completion

September 2008

System Cost, Payback, and Financial Incentives Utilized

The PV system was $787,000 ($735,000 grant from Xcel's Renewable Development Fund plus $52K Merrick funds); 4-year expected payback for Merrick's portion. $250,000 for the GHP system (all Merrick funds); payback in less than 6 years.

Anticipated Energy Delivery When Purchased

100 kW PV, 110 ton geothermal

Actual Energy Delivered When Installed

No data yet, but the GHP system will be adequate for the needs of a 52,000-square-foot building.

Percentage of Total Energy Needs Delivered

The PV array provides 100% of the electricity for the building's GHP system and about 33% of the building's electricity.