Understanding fuel savings mechanisms from hybrid vehicles to guide optimal battery sizing for India

摘要

Global transportation-related CO_2 emissions are expected to substantially increase by 2050, with a majority of growth coming from rapidly developing countries like India. To understand the potential for using hybrid vehicles to limit the CO_2 emissions growth, this paper compares driving conditions and the fuel savings potential of hybrids in the USA and India. It is shown that hybrids offer more fuel savings potential in India than in the USA, largely because of the limited highway driving in India. In order of relative importance, the analysis shows that fuel savings from power-split hybrids come from: 1) enabling higher efficiency engine operation; 2) energy recovered from regenerative braking; 3) engine shutdown. This understanding of the fuel savings mechanisms of hybrids and their relative importance is used in assessing how smaller battery capacities for hybrids in India can be used to reduce costs for this highly cost-sensitive market while preserving fuel savings. A parametric analysis of battery size on fuel savings mechanisms is carried out, and it is shown that hybrid vehicles for Indian driving conditions should ideally have a power capacity between 15 and 20 kW, with 10 kW as a lower limit.