Impacts of Large-Scale Surface Modifications on Meteorological Conditions and Energy Use: A 10-Region Modeling Study

• DOI: 10.1007/s007040050082
• Publication Date: 2002-08-25T09:09:23Z
• Authors: H. Taha; S. Konopacki; S. Gabersek
• Keywords: Albedo (alchemy)

Q) E IMPACTS OF LARGE-SCALE SURFACE MODIFICATIONS ON METEOROLOGICAL CONDITIONS AND ENERGY USE: A IO-REGION MODELING STUDY U C .t: a.i E ..:.c IQ c cu Haider Taha, Steven Konopacki, and Sasa Gabersek Heat Island Project Environmental Energy Technologies Division FINDINGS a.... LL. .Q cu ;Z Several field-monitoring studies have shown that using high-albedo materials on and increasing vegetative fraction around buildings can save a significant amount of cooling energy use. Also, meteorological and photochemical modeling studies suggest that large-scale increases in albedo (e.g., of buildings and paved surfaces) and vegetative fraction can have beneficial impacts on urban climates and air qUality. These ear- lier studies pOinted to the need for a multi-regional assessment of the meteorological and energy-use im- pacts of surface modifications. They also pointed to the need for assessing these impacts on a year-round basis, e.g., quantifying potential penalties in heating energy use in winter in addition to savings in cooling energy use in summer. The study described in this paper is a first step in that direction. This paper summarizes results from a mesoscale modeling study to quantify the possible meteorologic~ and energy-use impacts of large-scale increases in surface albedo and vegetative fraction. Ten regions in the U.S. were characterized and simulated in base- and modified-surface conditions. TIme- and space- dependent meteorological variables were simulated for each region in four 3-day episodes to represent a range of seasonal variations. The base-case mesoscale simulations suggest heat islands of I-2°C in most urban areas analyzed in this study. The simulations also suggest that large-scale increases in surface albedo and vegetative fraction can almost offset the urban heat island intensity in most of these areas. The energy implication of a I-2°C re- duction in space-averaged air temperatures (around 2 pm local time) is a decrease of up to 10% in peak electricity demand. In terms of annual costs of energy use, the simulations suggest net savings in the order of $10-35 per 100 m of roof area depending on building type and region. Areas like Los Angeles, Hous- ton, Miami, and Phoenix seem to benefit most from the large-scale surface modifications described in this paper, whereas regions like Philadelphia seem to benefit the least.