Efficiency is a Low-Cost Energy Source
Making buildings more energy efficient has been identified for many years as a largely untapped solution to address climate change, energy security and fossil fuel depletion. In the late 1970s, Amory Lovins popularized the concept of negawatts -- the idea of that energy needs could be met by increasing efficiency instead of increasing production. In fact, Lovins' Rocky Mountain Institute has suggested that up to 75% of the electricity used in the U.S. today could be saved with efficiency measures that cost less than the electricity itself.2 Supporting this claim is a 2006 McKinsey Global Institute study asserting that there were sufficient economically viable opportunities for energy-efficiency improvements to keep annual global energy-demand growth at less than 1 percent through 2020. 3 Finally, the Vienna Climate Change Talks 2007 Report, published under the auspices of the United Nations Framework Convention on Climate Change, clearly asserts that, “energy efficiency can achieve real emission reductions at low cost.” 4
Roofs Play a Major Role
According to the U. S. Department of Energy, buildings account for about 40% of U.S. energy usage.5
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In addition, the commercial building envelope (of which the roof is an important part) is involved in over 40% of building energy usage.6
Roof-Related Energy Savings Potential
Each year in the United States, over 4 billion square feet of low-slope commercial roofs are installed, with approximately 25% on new buildings and 75% as roof replacements for existing buildings. If all of these roofs were installed using the most effective energy-efficiency practices available, $186 million in building energy costs could be saved within the first year. And if this trend were continued for a ten-year period, annual energy savings standards could exceed $1.8 billion annually, with cumulative savings of over $10 billion in 2008 dollars. 7
Simply Stated: We Can Do Better
In the mid-1970s, the state of California began implementing energy-efficiency measures, that included building code standards with strict efficiency requirements. During the following years, California's energy consumption remained approximately flat on a per capita basis while national U.S. consumption doubled.
As a result of these policies, California now has the lowest electricity use per person in the nation, demonstrating the success of a variety of cutting-edge energy efficiency programs and cost-effective building and appliance efficiency standards. 8
Energy Efficiency and Climate Change
Both in the United States and throughout the world, over 90% of all energy is derived from fossil fuels.9 As a result, energy conservation and energy efficiency measures offer a significant opportunity to mitigate the potential for climate change by reducing the amount of greenhouse gases, such as carbon dioxide, emitted into the Earth’s atmosphere.
(2) For more information, visit the Rocky Mountain Institute website
(3) Wikipedia article on Energy Efficiency
(4) Press Release: “Vienna UN conference shows consensus on ….climate change”
(5) Energy Information Administration (EIA) Annual Energy Review 2006
(6) Energy Information Administration (EIA) Commercial Buildings Energy Consumption Survey 2003.
(7) Center for Environmental Innovation in Roofing, Greening of the Rooftop Module 5, “Why Roof Green?”
Total roof-related energy costs based on a comparison between the roof insulation standards of ASHRAE 90.1-1999 and the preliminary roof insulation standards proposed in the 2007 initial draft of ASHRAE 189.1-P. A cool roof is defined as a roof offering 50% long-term solar reflectivity or the thermal equivalent for the service life of the roof. Best practice defined as 2 or more staggered insulation board layers to minimize thermal loss at board joints. Annual energy costs based on 4 billion square feet of total annual roof installations, $0.12 / K WH cooling energy cost, $1.00 / therm heating energy cost, 2.0 cooling COP, and 75% heating efficiency. Assumes 20% of roofs are replacing existing cool roofs, 5% of roofs are installed over unheated spaces, and 20% of roofs are installed over non-cooled spaces. Calculations derived using the EnergyWise Calculator for gross heating and cooling costs and the DOE Cool Roof Calculator for cool roof energy costs.
(8) California Energy Commission Integrated Energy Policy Report 2007
(9) International Energy Agency World Energy Outlook 2006