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Title: Scaling of economic benefits from Green Roof implementation in Washington, DC.

Green roof technology is recognized for mitigating stormwater runoff and energy consumption. Methods to overcome the cost gap between green roofs and conventional roofs were recently quantified by incorporating air quality benefits. This study investigates the impact of scaling on these benefits at the city-wide scale using Washington, DC as a test bed because of the proposed targets in the 20-20-20 vision (20 million ft{sup 2} by 2020) articulated by Casey Trees, a nonprofit organization. Building-specific stormwater benefits were analyzed assuming two proposed policy scenarios for stormwater fees ranging from 35 to 50% reduction for green roof implementation. Heat flux calculations were used to estimate building-specific energy savings for commercial buildings. To assess benefits at the city scale, stormwater infrastructure savings were based on operational savings and size reduction due to reduced stormwater volume generation. Scaled energy infrastructure benefits were calculated using two size reductions methods for air conditioners. Avoided carbon dioxide, nitrogen oxide (NOx), and sulfur dioxide emissions were based on reductions in electricity and natural gas consumption. Lastly, experimental and fugacity-based estimates were used to quantify the NOx uptake by green roofs, which was translated to health benefits using U.S. Environmental Protection Agency models. The results of themore » net present value (NPV) analysis showed that stormwater infrastructure benefits totaled $1.04 million (M), while fee-based stormwater benefits were $0.22-0.32 M/y. Energy savings were $0.87 M/y, while air conditioner resizing benefits were estimated at $0.02 to $0.04 M/y and avoided emissions benefits (based on current emission trading values) were $0.09 M-0.41 M/y. Over the lifetime of the green roof (40 years), the NPV is about 30-40% less than that of conventional roofs (not including green roof maintenance costs). These considerable benefits, in concert with current and emerging policy frameworks, may facilitate future adoption of this technology.« less
Authors:
; ; ; ; ; ;
Publication Date:
OSTI Identifier:
982667
Report Number(s):
ANL/EVS/JA-65920
Journal ID: 0013-936X; TRN: US201015%%1274
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environ. Sci. Techol.; Journal Volume: 44; Journal Issue: 11 ; Jun. 1, 2010
Research Org:
Argonne National Laboratory (ANL)
Sponsoring Org:
SC; China Scholarship Council
Country of Publication:
United States
Language:
ENGLISH
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 03 NATURAL GAS; AIR CONDITIONERS; AIR QUALITY; CARBON DIOXIDE; COMMERCIAL BUILDINGS; ECONOMICS; ENERGY; ENERGY CONSUMPTION; HEAT FLUX; IMPLEMENTATION; NATURAL GAS; NITROGEN OXIDES; ROOFS; SCALING; SULFUR DIOXIDE; US EPA; WASHINGTON