In a new seminal study by Frontier Economics on the efficiency of battery-electric driven vehicles vis-a-vis current-based fuels it was determined that there is hardly any difference between the two: vehicles with combustion engines powered by climate-neutral fuels based on green electricity (e-fuels) have a similarly good overall energy balance as battery-powered vehicles. The study is based on an overall comparison of efficiency.
According to the study, the efficiency of the direct use of green electricity in battery electric cars, which has been shown to be around 70 percent in previous conventional analyses, shrinks to 13 to 16 percent in the holistic analysis by Frontier Economics. This puts it in a comparable range to vehicles powered by combustion engines and renewable fuels. Their overall efficiency is 10 to 13 percent, depending on the scenario.
The reason provided by Frontier Economics is the following: in conventional analyses the extreme differences in the yields of solar or wind plants depending on the location are completely ignored. In other words, a solar plant at an average location in Germany generates only about 40 percent of the amount of electricity per year that a comparable plant in North Africa produces. This higher electricity yield per plant can be used for road transport by importing hydrogen or synthetic fuels to Germany. For battery electric vehicles, on the other hand, one is largely dependent on domestic renewable electricity generation.
Further, electric cars must be able to be charged even when the sun is not shining and the wind is not blowing. In a 100 percent renewable electricity system, a certain proportion of the electricity for battery electric vehicles will therefore also have to be made available via the detour of intermediate storage via hydrogen, which is then converted back into electricity in gas power plants. Also it is often not taken into account that vehicles require additional energy for cooling and especially for heating the interior.
Dr. Jens Perner, head of the study, sums up: "The study shows that, when all relevant efficiency criteria are considered as a whole, there is hardly any difference in efficiency between vehicles with battery electric drive and those powered by climate-friendly, electricity-based fuels. The reason for this is in particular the importability of electricity-based fuels. This makes it possible to use high-yield locations for the production of wind and solar power worldwide. The efficiency advantage of battery electric cars, as cited in conventional studies, is largely offset by this import capability of fuels".