Answers

Here are some important basic issues I discovered:

1.  Coal-fired utility plants generate about 70 % of Colorado’s electricity. We cool our homes and buildings primarily with coal, and heat our indoor air and water primarily with natural gas. We Coloradans use about 10% more energy, and therefore more of our money, heating our homes than cooling them. Heat gain and heat loss can be significantly affected by attic ventilation and insulation and roofing choices.
2. Coal and natural gas are non-renewable resources that produce greenhouse gas (CO2). Solar power and wind power are renewable energy resources that produce no CO2. (Xcel is on course to produce 15–20% of Colorado’s electricity with renewable energy in the next 15 years.) Solid, still-functional rooftops are the site of choice for most photovoltaic (PV) and thermal solar systems.
3. Most steel roofing products are made from 35–85% recycled material and are 100% recyclable; and every pound of recycled steel used in manufacturing prevents 1,800 lbs. of CO2. Products with an Energy Star rating provide higher reflectivity and emissivity, for a cooler house, less energy usage, a cost savings, and less CO2.
4. U.S. concrete production, including concrete roofing tiles, causes roughly 8% of all CO2 emissions. Clay tiles have a smaller environmental impact in their manufacturing and can be more durable and attractive. End-use tire rubber, hose, plastics, and carpet are now being used for high-recycled-content roofing products, the installation of which reduce end waste in landfills and curtail the use of high embodied-energy materials. For durability, value, and budget, however, asphalt shingles are preferred for most residential construction. Some asphalt shingles are Energy Star-rated, and lighter colors provide greater cooling benefits than darker ones. Currently, 99% of tear-off asphalt shingles are not recycled in the U.S. (100% go to the landfills in Colorado), though a handful of states use them in their hot mix asphalt for roads. Every pound of tear-off shingles recycled prevents 26 lbs. of CO2.