| Our urban infrastructure systems are stressed. The decay of water infrastructure is spurring demand for innovative solutions for stormwater management. Concurrently, the transition of predominantly coal-based utilities to renewable portfolios is slow, resulting in continuing adverse health impacts from air pollution. The need for emissions management and resilient water infrastructure in cities will further increase as the world's population continues to move to urban centers.This dissertation explores the technical, economic, and policy opportunities for vegetated roofs as one solution to stormwater and energy emissions management. The objective was to explore policy strategies to integrate green roofs into emissions management using quantitative economic and physical-chemical modeling tools.This dissertation quantifies the green roofs benefits for Washington DC both at building-specific and city scale. For building-specific scale, we evaluate stormwater benefits, Energy savings and air quality improvement benefits for a2000m2roof area commercial building. For stormwater benefits, we consider two scenarios:$0.33/m2/y,50%off;＄0.33/m2/y,35%off. We also use two methods, EnergyPlus developed by US DOE and1-D heat flux equation, for estimating green roofs energy savings.For air quality improvement benefits, also two estimate methods for testing, experimental data statisitics and SEDUM model calculation.While we made assessment for green roofs benefits, including stormwater fee-based benefits, stormwater operational benefits, stormwater size reduction benefits, energy fee-based benefits, avoided emission benefits, air conditioner size reduction benefits,and air quality improvement for Washington DC at city-scale based on'20-20-20'plan proposed by Casy Tree and Limino-tech. Energy fee-based benefits were evaluated by EnergyPlus model. CO2, NOx, SO2avoided emission benefits were calculated by reductions in electricity and natural gas associated with their emission factors in power plants and space-heating equipment sectors. Scaled energy infrastructure benefits were calculated using two size reductions methods for air conditioners. Lastly, the air quality improvement benefits were also calculated based on two estimate methods, experimental data statisitics and SEDUM model calculation.The results showed the stormwater benefits are＄232-332/y, energy savings were$708-2500/y, and the air quality benefits are＄255-3445/y for2000m2green roof on a commercial building in Washington DC. While for the city-scale, the stormwater fee-based benefits are estimated at＄0.22-0.32M/y, the operational savings are＄0.95M/y, the infrastructure size reduction benefits are＄0.08M/y, energy fee-based savings are＄0.87M/y, however, the avoided emission benefits are＄0.09-0.41M/y, the air conditioner size reduction benefits are＄0.02-0.04M/y, and the air quality improvement benefits are estimated at$0.24-3.27M/y for Washington DC.Lastly, all these benefits are integrated into an economic framework model net present value (NPV) to compare the cost of conventional roof to green roof. The results indicated that the40-year NPV of green roofs is25to39percent less than that of conventional roofs at building-specific scale mainly due to energy savings during all the benefits for Washington DC. For Washington DC city-scale, the40-year NPV of green roofs is30to41percent less than that of conventional roofs also mainly due to energy savings during all the benefits for Washington DC.The results also illustrated the breakeven of green roofs NPV are7-21years for Washington DC.Also uncertainty and sensitivity analysis is conducted for green roof system in Washington DC. The model estimated that green roofs NPV break even are decreased by1-2year by these uncertainty energy-relative prices without CO2cap-and-trade system. The main driver for the shorter break even is the commercial electricity prices (mean value:2.1±1.1%), followed by residential natural gas prices (mean value:1.9±1.4%), and CO2prices (mean value:0.7±0.4%). While the model estimates show that cap and trade induced price increases have the potential to decrease the NPV break even of green roofs by4-5years. The main driver for the shorter break even is the CO2allowance valuation (mean value:4.8±3.7%and2.2±0.7%), followed by commercial electricity prices.Finally, we implement the established green roofs benefits evaluation methods based on Washington DC system to City of Vancouver.We evaluate stormwater benefits, energy savings, and air quality improvement benefits for green roofs system for City of Vancouver, and more focused on stormwater benefits, including stormwater fee-based benefits, receiving water quality improvements benefits, Reduction in major storm flows benefits (DCC), reduction in risks due to climate change benefits, reducing storm water impact to aquatic habitat benefits, reduction of receiving stream erosion benefits. The receiving water quality benefits are estimated based on two scenarios. Then all these benefits are incorporated inot NPV model to determine the break even of green roofs.The results indicated the total stormwater benefits are＄4.36-5.62M/y, the total energy savings are＄2.69-3.11M/y, and the total air quality improvement benefits are＄2.54-21.24M/y for green roofs for City of Vancouver at city-scale.The40-year NPV of green roofs is28to48percent less than that of conventional roofs mainly due to total stormwater benefits during all these benefits.The break even of green roofs are found to be6-21years for City of Vancouver.Analysis of current stormwater, energy savings and air quality policies showed that market-based incentives can close the cost differential once both stormwater and air quality incentives are considered. This work is sufficiently robust to demonstrate the economic and emissions mitigation potential to be included in best available control technology (BACT) consideration. Yet, market-based policy incentives are currently insufficient for widespread adoption.
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