On August 19th the Southeast Clean Energy Resource Team toured two green landmarks in the Twin Cities: The Green Institute’s Phillips Eco-Enterprise Center Building in Minneapolis and District Energy in St. Paul. Let me take a few moments to share with you what we learned!
Phillips Eco-Enterprise Center
From 1:30-2:30pm our group toured The Green Institute’s Phillips Eco-Enterprise Center. The Phillips Eco-Enterprise Center (PEEC) is The Green Institute’s flagship and a national model of comprehensive sustainable design. The building was a pilot for and helped inform the creation of the United States Green Building Council’s Leadership in Energy and Environmental Design (USGBC’s LEED), which has in the last ten years risen within the green building movement as the preeminent national green building standard.
The Green Institute had five main goals in mind when planning PEEC:
– Goal 1: Ensure Occupant Health
– Goal 2: Reduce Energy Load
– Goal 3: Use High Quality Salvaged and Recycled Materials
– Goal 4: Restore Native Landscape and Conserve Water
– Goal 5: Advanced Design
Features of the Phillips Eco-Enterprise Center include geo-exchange heating and cooling, energy recovery ventilation, solar PV (a 34kW array), active daylighting, energy management system, green roof (with both native and European grass varieties—they were seeking to compare the two; native seem to do better), 100% stormwater retention, low-emission coatings, and salvaged and recycled materials used in construction (and less that 10% of the construction materials went to a landfill during the building process).
To learn more about the Green Institute and Phillips Eco-Enterprise Center, visit The Green Institute’s brand new Web site or read a CERTs case study about PEEC’s green rooftop.
District Energy
From 3:00–4:00pm we toured District Energy in St. Paul. Launched as a demonstration project in 1983, District Energy was Saint Paul’s response to the energy crises of the mid- and late-1970s. The venture was a public/private partnership among the City of Saint Paul, State of Minnesota, U.S. Department of Energy and the downtown business community, all of whom wanted to prove the viability of a hot water district heating system in a state with cold winters (hot water is more efficient and you can pump it further).
In 2003, District Energy became a green energy service provider following construction of an affiliated combined heat and power (CHP) plant that is fueled by a renewable resource—clean, urban wood waste. The wood is sourced from within a 50-60 mile radius from low-grade woods including residues from municipal parks, DNR projects, land clearing, tree removal contractors, diseased trees (priority), storm damage, and some construction and industrial sources (must be clean). District Energy estimates that their operation puts $8 million a year back into local economy.
Using renewable energy, the CHP plant simultaneously produces about 65 megawatts of thermal energy for District Energy and 25 megawatts of electricity for Xcel Energy. This in turn has allowed it to reduce CO2 emissions by 280,000 tons and has provided customers with stable rates for heating and cooling. It is the largest wood-fired CHP plant serving a district energy system in the nation—and just as a point of comparison, Sweden has 170 times the district heating capacity of District Energy St. Paul.
District Energy currently heats more than 185 buildings and 300 single-family homes (31.1 million square feet, about 80% of downtown St. Paul buildings). The heating system spans from the Wellstone Center to the Phalen Corridor. They are considering expanding the heating system down University Avenue during the light rail development. The District Cooling systems cools more than 95 buildings (19 million square feet, about 60% of downtown St. Paul). Its cooling system includes two chilled water storage tanks that hold 6.5 million gallons of water chilled at night, during off-peak electrical hours, for consumer use during the day. This has helped reduce peak electric demand by 9MW.
To learn more, visit District Energy’s Web site or read a CERTs case study on the facility.
