The objective of this paper is to provide a set of analytical tools for various stakeholders such as policy makers, manufacturers and consumers, to identify the optimal design and evaluate the economic and environmental performance of tri-generation systems for home and neighborhood refueling. An interdisciplinary framework and engineering/economic model are developed and applied to assess these systems. Major tasks include modeling steady state system performance, exploring the optimal design of a system, estimating the cost of electricity, heat and hydrogen, and system CO2 emissions, and comparing the results to alternatives. Sensitivity analysis is conducted, and the potential impacts of uncertainties in energy prices, capital cost reduction, government incentives and environmental cost are evaluated. Policy implications of the modeling results are also explored. Three case studies using California residential energy consumption data are presented.