An Alternative Approach to PV System Life Cycle Cost Analysis (PV LCC): Phase II

This analysis expands the photovoltaic (PV) life cycle cost (LCC) results presented at ASES 2004. That paper presented the model and concept used to develop PV LCC, and it showed the results of the analysis of over one hundred systems monitored by the Florida Solar Energy Center (FSEC). FSEC began tracking cost, performance and reliability data for systems installed in Florida in 1998, with data now available through a web-accessible database. For the majority of the 124 systems, installed cost information was collected as part of the state’s PV rebate and PV for schools programs. Results presented previously [1] indicated that over an assumed 20–30 system life time a PV system will have a positive life cycle cost. That is, a negative total return on investment. These results were based on actual cost, performance, maintenance, and reliability data. In the baseline case, average total system costs over the lifetime were 32.4¢/kWh while electricity savings totaled 3.7¢/kWh netting a life cycle cost of 28.7¢/kWh. While based on actual data from over 100 installed systems — some installed for over 6 years — a number of conservative assumptions also drove the analysis, such as the exclusion of the state’s rebate programs (varying from $2 to $5 per DC Watt) which impacted nearly all of the systems in the analysis. Since the first presentation of these results the PV LCC model has been further developed to incorporate additional performance information and expands the sample of systems incorporated. This paper will thus provide further insight into the relative importance of various up-front and on-going costs to the overall lifetime economics of a system. The paper will also address additional sensitivity analysis performed. Particular attention is paid to inverter mean time between failure (MTBF), the impact of incentives, and basic financial assumptions used in the model such as the discount rate and electricity rates. Various scenarios are considered in asking the question of what is necessary for the system LCC to break-even.