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Protecting the Box. Creating and Conserving Energy for Big Box Buildings and Stadiums with Roofs By Rey Arnaldo Phillips Santos rphillips@kentlaw.edu Spring 2004 Energy Law Professor Bosselman Chicago-Kent College of Law. Goals. Develop techniques of profitable sustainability
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Protecting the Box Creating and Conserving Energy for Big Box Buildings and Stadiums with Roofs By Rey Arnaldo Phillips Santos rphillips@kentlaw.edu Spring 2004 Energy Law Professor Bosselman Chicago-Kent College of Law
Goals • Develop techniques of profitable sustainability • Reduce demand for baseload power plants by • Increasing amount of power produced during peak demand • Reducing the demand for power
Audience • Malls • Big box stores • Wal-Mart • Target • Circuit City • Best Buy • Etc. • Stadiums Photo from www.generalgrowthproperties.com/malls/photoinfo.asp?smuid=670#
Why Stadiums? • High-Profile • Easy way to communicate to people of all ages • Innovative Designs • Good publicity for the teams
Big Box Stores • Many of these same ideas can be applied to big box stores. • Target is already famous for giving to schools. This would be another connection to schools and community. • A stadium naming tie-in with a solar panel push on all stores would be big, positive publicity, plus economically and environmentally friendly
Fun with EstimatesPossible Square Footage of Flat Roofs in USA
Conventional Flat Roofs • Subject to large swings in temperatures that cause cracking and leaking • Temperatures can reach 176 degrees Fahrenheit • Last between 5 and 20 years before replacement • Avg cost per square foot is $55 to $85
Urban Heat Island Effect • The predominance of dark surfaces in urban areas—from roofs, streets, parking lots—results in higher temperatures by as much as 6 to 10 degrees Fahrenheit. • About 60% of roofs in Chicago are dark colored.
Three Roof Types • Solar Roofs • Green Roofs • Reflective Roofs
Solar Roofs Photo from http://iseanetwork.org/tour/chicago/
Clean power Free energy Helps shade roofs Modular Existent roof friendly Long-lasting May be used for emissions trading Advantages
Advantages • Gives power when it is needed most • During peak periods • Daytime • Summer • Result: Reduces number of baseload plants • Helps achieve Illinois renewable energy goal • Reduces risk of price volatility
Disadvantage • Cost • According to one estimate, cost is 11 cents per kWh • According to another, the system pays itself off in 6 years • Little agreement in industry
Illinois Department of Commerce and Economic Opportunity (DCEO) • Division of Energy Conservation and Alternative Energy • Promotes Energy Efficiency • Education • Identification of means of financing • Bureau of Energy and Recycling • Alternative Energy Development Section • Renewable Energy Resources Program • 20 ILCS 687 Article 6
Illinois Department of Commerce and Community Affairs (DCCA) • Rebate Program • $6/watt up to $5000 • There used to be other programs, including grants up to $300,000, but those have been scrapped.
Chicago Photovoltaic Incentive Program(a.k.a. ComEd Solar Electric Incentive Program) • In 2004, grants rebates of $1000 per kW, for systems between 1 and 50 kW • Must be eligible under the Renewable Energy Resources Program • Must purchase from Spire Solar Chicago • Must be in Chicago • Must have a ComEd account
Mainstay Energy Rewards Program • Private company which buys Renewable Energy Credits from small to medium sized producers of renewable energy. • They pay 2 to 5 cents per kWh • They then sell these credits • Efficient because they can gather volume and specialize while saving businesses money
Green Tag www.mainstayenergy.com
Fun with EstimatesPossible Square Footage of Flat Roofs in USA
A 50 kW unit needs about 5000 to 5500 square feet of roof space. • In Chicago, at a 0 degree angle, it should produce about 51,700 kWh per year. • Applied to the billion square feet of estimated roof space, more than 185,000 units could be installed. • Result: 9,564,500 MWh/year
Savings and Costs • This would save about 7.6 million tons per year of carbon dioxide being released. • But the cost would not be small. At current prices it could come to as much as $93 billion dollars. • Over 30 years, the cost per kWh comes to about 3.22 cents/kWh.
Green Roofs Chicago’s City Hall (L) www.greenroofs.org (R) www.roofmeadow.com
Extensive Green Roofs • 2-4 inches of soil • 12 to 40 pounds/sq. ft. of roof area • Short, drought resistant plants with shallow root systems like sedum and hard fescue Photo from www.greenroofplants.com
Extensive Green Roof System Photo from www.hydrotechusa.com
Yellow Sedum Photo from http://wisplants.uwsp.edu
Hard Fescue Photo from http://wisplants.uwsp.edu
Intensive Green Roof System • 6-12 inches of soil • 80 to 150 pounds/sq. ft. of roof area • Able to host deeper-rooted plants, e.g. shrubs and trees • More maintenance needs, e.g. irrigation and pruning
Conserves energy by moderating temperatures within buildings Extends roof life Reduces noise Aesthetics Absorbs rainfall Reduces runoff Filters rainfall Plants filter air Combats Urban Heat Island Effect Advantages
Disadvantages • Not possible for all roofs based on architectural need • Some maintenance necessary • Design and cost is about 50% more expensive than a conventional roof, though this is recouped by the fact that the roof lasts twice as long.
Reflective Roofs www.ornl.gov/sci/roofs+walls/research/reflective.htm
Reflective Roof System • Can reduce roof surface temperatures by 60 degrees Fahrenheit • Most basic technique – paint the roof with a reflective paint • Many suppliers of coatings and coverings • Some materials may be recycled, e.g. Thermoplastic Polyolefin
Advantages • Relatively inexpensive—many cost the same as dark-colored roofing materials • Moderates temperatures • Extends roof life • Reduces Urban Heat Island Effect by reducing the total area of dark, heat-absorbing surfaces
Disadvantages • Short life • Reflectance reduces over time because of dirt and weather damage
Roofed Stadiums • Glasgow Ibrox, Scotland • Seats 57,000 • Renovated in 1997 • Light colored roof reflects the heat • Roof over all of the stands protects fans from the elements
Roofed Stadiums • Kingston Communications Stadium, England • Seats 25,500 • Light colored roof reflects the heat • Angle can be directed toward the sun for solar panels Kingston Communications Stadium, England, seating about 26,000
Conclusions • Solar • Most expensive up front cost • Incentives would help defray • Competitive over long term • Reduces risk to price volatility • Very clean • More research might improve efficiency of panels
Conclusions • Green roofs • Should be incentives • Failing incentives, energy efficiency requirements in the building code which would encourage green roofs • More research is needed for percentage of savings • Greatest aid to Urban Heat Island Effect reduction
Conclusions • Reflective roofs • Are so inexpensive that they simply make good business sense. • No incentives should be needed, but like with the green roofs, energy efficiency requirements could encourage them.