Forecasting of Fuel cell technology in hybrid and electric vehicles using Gompertz growth curve

Abstract

This paper is intended to forecast Fuel cell technology using patent literature and technological growth curve models. Technology maturity of the Fuel cell technology is determined from the forecast. Patent data pertaining to Fuel cell technology is extracted from United States Patent and Trademark Office (USPTO) from 1976 to 2012. Fuel cell technology patents are grouped with the help of International Patent Classification (IPC) classes. A demographic analysis is done on World patents pertaining to Fuel cell technology to identify important patent groups and variables for modelling. From the literature study various growth curves in particular Logistic, Gompertz and Weibull Curves are considered to forecast the Fuel cell technology. The upper limit used in this analysis is defined and a formula to evaluate the same is proposed. An algorithm already existing in the literature is used to find the starting year or base year of the normalized cumulative frequency of patent grants plot. After the analysis, Gompertz curve is considered as the best model to forecast Fuel cell technology. The fit of the transformed Gompertz curve is determined with the help of adjusted R-Square value. Parameters of Gompertz curve are estimated using natural logarithmic transformations and regression. These parameters are substituted back in the Gompertz curve and error terms are checked for auto correlation and normality assumptions. Technology Maturity has been evaluated using Gompertz curve and the same is compared with Nonlinear Least Square technique. The forecasting errors over the forecast region are estimated using Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE).The important aspect of evaluating the technology maturity of a particular technology will be the identification of important patent groups that form the technology and these groups are used to evaluate the upper limit of the technological growth curve. From the Analysis, the Fuel cell technology is categorized as an “EMERGING TECHNOLOGY”. Current forecast of Fuel cell technology maturity is very long and therefore a policy intervention or a subsidy from the Government or a new breakthrough in the Fuel cell research will reduce the forecast time.