LIT 5: Decision-support and Emissions Prediction Interactive Cities Tool (DEPICT)

When evaluating a district (re)development plan, urban planners and government agencies consider the energy consumption and impact on air quality that the proposal would create. In California, the air quality impact is regulated by the California Environmental Quality Act (CEQA), which requires that the estimated emissions of greenhouse gases and other selected particles be reviewed and approved during the design phase, leading potentially to mitigation measures aiming at reducing these emissions.

State of the Art

The emissions estimates are generally generated by an accredited software, such as the California Emissions Estimator Model (CalEEMod) which uses empirical data and equations to calculate the predicted emissions from construction, building operation and vehicles. The data used comes from public database which are built on survey results. The impact of mitigation measures on emissions is also determined empirically by deducing the typical measured impact off the baseline results. While this method offers fast results, which requires minimal user input, it cannot reliably model atypical building types or mitigation measures. It is also unreliable when applying measures that have variable impact, depending on use and location, such as photovoltaic technology.

Value Proposition

The Decision-support and Emissions Prediction Interactive Cities Tool (DEPICT) aims at predicting the cross-sectoral (building construction, operation and vehicles) energy consumption and greenhouse gases emissions at campus and urban scale. It leverages capabilities of multiple modeling tools: EnergyPlus for building operation, CalEEMod for building construction and gas vehicle, BEAM for electric vehicles and SAM for building–integrated photovoltaics. It distinguishes from other cross-sectoral model such as CalEEMod or BEST in that it uses physical models, rather than empirical models, for all sectors, which allows for a more accurate and customizable quantification. It is relevant for short-term multi-sectoral decision making by developers and city planners and long-term policy making by municipal and state officials.

Application

DEPICT is currently under development for a case study project with an urban developer in San Francisco, working on three distinct redevelopment projects in the Bay Area. The current capabilities of the tool are tailored to the needs of the client, with a strong focus on a reliable vehicle modeling, but future development will further enhance the tool features for a broader range of applications.