资源环境科技发展态势分析平台

Modern residential land development has trended toward densification, resulting in limited space to plant shade trees. As a result, shade trees are often planted in sub-optimal locations around homes for energy conservation benefits. Using a simulation program-called EnergyPlus, we examined the effects of existing trees on energy consumption of recently constructed homes in three U.S. cities with distinctly different climates: Metro Minneapolis, MN, Charlotte, NC, and Metro Orlando, FL. We used remote sensing to identify placement of existing trees around homes, revealing that there were 1.5 to 2.9 trees within 15 m of the homes on average. When modeled as large-stature deciduous trees in the simulator, existing trees provided average annual energy savings per parcel of 14 kWh (MN), 25 kWh (NC), and 44 kWh (FL). We then tested an alternative tree placement strategy that spatially reconfigured the existing trees, based on parcel orientation, to both minimize space conflicts and maximize energy savings. This alternative strategy optimized the placement of over 70% of the existing trees and significantly improved annual energy savings per parcel to 57 kWh (MN), 47 kWh (NC), and 103 kWh (FL). In Metro Orlando, the impact of optimization on annual energy savings across our sampling frame was 574,000 kWh. Although our alternative strategy was no more effective than the conventional strategy (always plant a shade tree on the west aspect). It is more responsive to space constraints and therefore can guide developers and homeowners more practically toward optimal tree placement for energy conservation. (C) 2016 Elsevier B.V. All rights reserved.