Because Photovoltaic system tends to save the energy expenditure across the life span of the systems, this paper uses life cycle costing (LCC), saving-toinvestment ratio (SIR), and discounted payback period (DPP) methods to construct the renewable energy evaluation framework in Taiwan. The benefits of PVs mainly derive from energy cost savings, enhanced power quality and reliability, reduced environmental emissions, rebates, and other incentives. Based on the field data of PV-projects located at Taiwan, the paper identifies the technical and economic parameters of the systems evaluation model. The empirical case showed that the saving-to-investment ratio of the BIPV systems with/without government subsidy is not currently feasible in Taiwan. After examining critical factors of the PVs-project, the sensitivity analysis of the future PVs-project was shown. Based on the empirical residential case with a reasonable PR value, the results of sensibility analysis showed that BIPV will become one of the dominant renewable energies in the near future if good, integrated building design is available.

State-of-the-art economic analyses of renewable energy technologies (RETs) include using portfolio theory in renewable energy policy planning and using Monte-Carlo simulation to attain the risk profile of the technologies. Most economic analyses now co-list the risk index and GWP index as results of research/policy planning reports. After examining the variants of economic models for RETs, the risk dimensions of traditional energies and RETs were compared. The asymmetry risks allocated between traditional energy and RETs were shown. Combining these asymmetry risk allocations, a project-based RETs financial feasibility model which simultaneously integrates cost and risk information with respect to renewable and traditional energy technologies, was developed. Results of the analysis showed that the risk premium of traditional energies should include the effects of the escalation and volatility of fuel prices. On a national/regional level, the subsidy of fossil fuels for traditional energy production, which is embedded in the economic development policy, should be recovered and the degree to which investment of RETs improved the efficiency of cost-risk portfolio should be measured. On a project-based level, the effect of fuel price escalation and the saving of cost of risk-mitigation should be included.