Plug-in Hybrid Vehicles provide substantial environmental advantages compared with comparable Internal Combustion Engine Vehicles.
Two Plug-in Hybrid Vehicles energy consumption, CO2-emission and locally polluting emissions were tested in VTT’s emission laboratory in Finland, at +23°C and -7°C and in different drive cycles and drive modes. Together with data on usage pattern extracted from a survey of Plug-in Hybrid Vehicles owners in March 2016, the measurements enable an assessment of the environmental impacts of these vehicles in Norwegian traffic conditions.
The general conclusion is that these vehicles provide substantial environmental advantages compared with comparable Internal Combustion Engine Vehicles. The CO2-emission is reduced 30-50% depending on vehicle configuration, and local pollution does not seem to be an issue with these vehicles compared with Internal Combustion Engine Vehicles. They do however emit substantially more CO2 and consume much more energy than the type approval values. The type approval value does not seem achievable in real traffic. Some specific usage modes, for instance driving in cold climates under heavy loads with an empty battery, can lead to excessive local emissions compared with the official type approval limits.
Little has been known about Plug-in Hybrid Vehicles real world energy consumption, emission and usage characteristics under Norwegian road and climate conditions, and typical usage patterns. The testing of these two vehicles demonstrates that Plug-in Hybrid Vehicles are a non-uniform category of vehicles. The amount CO2 and local pollutants these vehicles emit will depend heavily on how the vehicles are designed, and how, when and where they are used. They are high performance vehicles and care should be taken when identifying vehicles to compare emissions with.
The testing supports a conclusion that the users driving pattern needs to match the characteristics of these vehicles to reap the maximum benefits in terms of reduced CO2-emission and less local pollution.
Full report: Experimental testing of Plug-in Hybrid vehicles. Experimental testing of Plug-in Hybrid vehicles. TØI Report 1539/2016.
Authors: Erik Figenbaum, Christian Weber.
The report is written in English.