Daniel Villa

Sun City progress report : policy effects on photovoltaic adoption for city planning.

This progress report documents the Sun City modeling approach, intended to be an analytic tool for city planners. It is midway in development and this report provides the design basis to provide the mathematics for policy considerations applied to PV market acceleration. It assesses the effects on market diffusion for nine commonly used policies: cash incentives, third party financing, group purchase programs, community solar projects, feed-in-tariffs, property assessed clean energy financing, low interest loans, property and sales tax incentives, and streamlined PV permitting processes. Generic forms of all of these policies are modeled in a system dynamics PowerSim Studio model using a concept called the photovoltaic favorability (PVF). PVF is equal to the difference between the ratio of conventional electricity costs to levelized electricity costs of a PV system and four barrier ratios. The barriers are present to model inhibiting influences on human decisions and financial limitations. They include down payment costs, month to month payment costs of financing, time to net profit, and time to lower payments. Each barrier term is divided by a tolerance term which represents the potential that consumers of the region can typically invest. PVF is quantified across a range of limited budget financing and cash incentives options which are then consumed from greatest PVF to least PVF. Finding the overall PVF requires iteration on a variation of the Bass diffusion model. This iterative scheme is tied in a feed-back loop to local and national PV learning curves which in turn quantify reductions in the cost of PV for future time steps based on user input learning rates. The modeling has been wrapped into a graphical user interface which will allow city planners to easily compare and demonstrate multiple scenarios. Data for the DOE sponsored Solar America Cities and for Albuquerque, New Mexico has been entered into the model in order to minimize data collection efforts by city planners.

Human ecology, resilience, and security in 2030.

Resilience is a quality that allows human systems to rebound from shocks, such as droughts or famines, floods, conflict events, and others. Human resilience is tightly coupled to human ecology, including population dynamics, resource availability, and resource consumption. The Human Resilience Index (HRI) and Modeling (HRIM) Project provides a set of tools that help explore the links among human ecological conditions, human resilience, and conflict. The HRIM allows users to simulate future scenarios and mitigation strategies. Historic calculations using the HRI show numerous times and places where declining HRI values have corresponded to instability and conflict, supporting the hypothesis that poor human ecological conditions can contribute to conflict. Seven indicators are used to calculate the HRI: population growth rate, population density, caloric intake per capita, renewable fresh water per capita, arable land per capita, median age, and population health (including infant and child mortality and life expectancy). The HRIM provides a set of tools for evaluating alternative mitigation strategies to help improve human ecological conditions, increase resilience to shocks, and reduce the threat of instability and conflict.

Risk assessment of climate systems for national security.

Climate change, through drought, flooding, storms, heat waves, and melting Arctic ice, affects the production and flow of resource within and among geographical regions. The interactions among governments, populations, and sectors of the economy require integrated assessment based on risk, through uncertainty quantification (UQ). This project evaluated the capabilities with Sandia National Laboratories to perform such integrated analyses, as they relate to (inter)national security. The combining of the UQ results from climate models with hydrological and economic/infrastructure impact modeling appears to offer the best capability for national security risk assessments.