Using a stock-flow model based on data from Norway, a researcher at the country’s Institute of Transport Economics (TØI) has calculated the energy transition time lag for motor vehicles under a number of scenarios.
In his paper in the journal Energy Policy, Lasse Fridstrøm finds that in the most optimistic scenario for the energy transition affecting Norwegian registered vehicles, zero emission vehicles (ZEVs) would constitute 90% of the flow of new passenger cars in 2024; however, 90% penetration of ZEVs into the stock of passenger cars would not occur until 2039.
For light duty freight vehicles (LDVs), the corresponding milestones would be reached in 2026 and 2040, respectively, according to the same optimistic policy scenario.
The stock-flow modeling approach accounts for the stock of vehicles and the flows into and out of this stock.Based on the Markov chain principle—by which the flows and stock in year t depend only on the stock of the previous year t-1, Fridstrøm’s model projects year-by-year changes in the fleet of vehicles in each category, classified by age, weight and powertrain (energy) technology.
The model specifies 11 technologies: gasoline internal combustion engine (ICE); diesel ICE; battery electric vehicle (BEV); plug-in hybrid electric vehicle (PHEV) with gasoline ICE; PHEV with diesel ICE; non-plug-in hybrid vehicle (HEV) with gasoline ICE; HEV with diesel ICE; hydrogen fuel cell electric vehicle (FCEV); natural gas ICE; kerosene ICE; and other.
The four different scenarios differ in terms of new vehicle acquisitions, but are identical in terms of transition rates—set in accordance with the average observed annual rates during 2010–2015.
The trend scenario is essentially an extrapolation of the changes in market shares observed between 2010 and 2015.
The ultra-low emission (ULE) scenario is designed to meet the Norwegian governments ambitious targets for the uptake of zero- and low-emission vehicles—by 2025, all new passenger cars and all new urban buses are to be BEVs or FCEVs. The same applies to new LDVs (cargo vans), to three quarters of all new interurban buses and coaches, and to half of all new HDVs (trucks and semitrailer tractors) by 2030.
The low emission (LE) scenario sees zero-emission automobiles obtaining market dominance at least by 2030.
The business-as-usual scenario posits new automobile sales changing only slowly from the market shares observed in 2016.
|Share of zero emission passenger cars, in four scenarios. Fridstrøm (2017). Click to enlarge.|
To measure the speed of transition, Fridstrøm used three indicators: (i) the share of zero emission vehicles (ZEVs); (ii) the average energy consumption per vehicle or freight ton kilometer; and (iii) the average CO2 emissions per vehicle or freight ton kilometer.
Among his other findings:
For automobile energy efficiency, the lag between innovation and penetration typically varies between 8 and 15 years; the LDV lag varies from 7-8 years to more than 20 years. For HDVs, in terms of energy consumption fer freight ton kilometer, the energy efficiency lag varies from 12 to more than 25 years.
A 90% reduction in the car stock’s mean CO2 emission rate is projected to occur in 2037 according to the most optimistic (ULE) scenario, but no sooner than in the second half of the century—if at all—if the current trend continues.
… a relatively high speed of transition will occur only if governments make exceptionally forceful policy instruments to bear on new vehicle acquisitions. More realistically, the energy transition within road transportation will take several decades. Achieving such a transition will thus require long-time political perseverance and resolution.—Fridstrøm (2017)
Lasse Fridstrøm (2017) “From innovation to penetration: Calculating the energy transition time lag for motor vehicles,” Energy Policy, Volume 108, Pages 487-502 doi: 10.1016/j.enpol.2017.06.026