Protecting the Box Creating and Conserving Energy for Big Box Buildings and Stadiums with Roofs By Rey Arnaldo Phillips Santos 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

Photo from alls/photoinfo.asp?smuid=670# Audience Malls Big box stores –Wal-Mart –Target –Circuit City –Best Buy –Etc. Stadiums

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

Typical Big Box Stores # of storesSmallestLargest Wal-Mart3,55942,000220,000 Target1,107125,000175,000 Best Buy75020,00045,000 Circuit City59915,00045,000

Fun with Estimates Possible Square Footage of Flat Roofs in USA Wal-Mart533,850,000 Target166,050,000 Best Buy22,500,000 Circuit City17,970,000 Subtotal740,370,000 Malls280,000,000 Total1,020,370,000

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

Photo from Solar Roofs

Information and map from MrSolar.com

From basics.html

Advantages Clean power Free energy Helps shade roofs Modular Existent roof friendly Long-lasting May be used for emissions trading

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

Fun with Estimates Possible Square Footage of Flat Roofs in USA Wal-Mart533,850,000 Target166,050,000 Best Buy22,500,000 Circuit City17,970,000 Subtotal740,370,000 Malls280,000,000 Total1,020,370,000

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.

(L) (R) Green Roofs Chicago’s City Hall

Photo from 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 Extensive Green Roof System

Photo from Yellow Sedum

Photo from Hard Fescue

Intensive Green Roof

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

Advantages 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

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.

Penn State test Ambient Air88° F Plastic-Sheet Roof140° F Gravel roof118° F Green Roof82° F

h/reflective.htm Reflective Roofs

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

Kingston Communications Stadium, England, seating about 26,000 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

Roofed Stadiums

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.