The role of biofuels in the Energiewende has been thrown into question, which is one reason why transformation in the transport sector has been so lethargic. EU-approved biofuels must emit at least 35 percent less greenhouse gas than fossil fuels, and will become even cleaner in the near future. First-generation biofuels – like bio-diesel and biogas derived from food crops – have come under fire for threatening biodiversity, contributing to deforestation or other damaging land conversion, and causing world food prices to rise. But second generation biofuels (also known as “advanced biofuels”), which are derived from feed stock, waste and recycled vegetable oil, can be used in conventional engines without harming the environment. Although they may not accomplish as much of the heavy-lifting as once thought, the question is: How much can biofuels do?
The track record of biofuels in Germany isn’t as lacklustre as that of e-mobility. In 2014, 5.6 percent of Germany’s energy usage in transport came from biofuels, reducing Germany’s greenhouse-gas footprint by five million tonnes (in 2013). German petrochemical companies had been required to blend diesel fuel and gasoline with 6.25 percent of biofuel. This requirement was dropped in 2014 in favor of an EU rule that oil companies lower the greenhouse gas emissions of their fuels by 3.5 percent starting from 2015, 4 percent from 2017 and 6 percent from 2020. The EU has directed that member states supply 10 percent of all transportation fuels with renewable sources such as biofuels by 2020.
Some experts believe that the potential to expand biofuels in Germany is considerable. “In Germany, as across the EU, the share of renewable energies in transportation, about 5 percent, is way beneath the potential,“ says Philipp Vohrer, director of the Berlin-based think tank Renewable Energies Agency, who points to the sustainability requirements for biofuels in the EU.
“For an Energiewende in transportation we need more biofuels,“ Vohrer says, as well as e-mobility and the shifting of traffic from road to rail. He points out that in contrast to passenger cars, where diverse technologies are available, for air traffic and heavy-duty trucks biofuels are so far the only options.
Some experts are also holding out hope for hydrogen. Germany’s ten-year National Hydrogen and Fuel Cell Technology Innovation Program provides a framework for hydrogen and fuel-cell research projects conducted by academic institutions and industry. But according to joint government and industry initiative Clean Energy Partnership, Germany only had 19 hydrogen filling stations operational in early 2016, financed by the federal transport ministry, Daimler, and the French oil and gas company Total. The number of hydrogen fuel-cell vehicles currently on the road in Germany: 100.
Hydrogen advocates have long touted the invisible gas as an abundant, storable, non-polluting form of chemical energy – and it is indeed all of these. Hydrogen has several potential roles as the fuel of the future: It can be burned in modified internal-combustion engines – like those of jets, turbines, four-strokes, and diesels. Yet the best near-term bet for transportation is hydrogen fuel cells, which are essentially little electrochemical factories that combine hydrogen and oxygen. In motor vehicles, they can store and create electricity.
Yet, despite the bluster, hydrogen remains controversial and unproven. Sceptics say the production of hydrogen is itself too energy intensive to make it worthwhile and that the technology is still far from road-ready.
“Hydrogen has been over-hyped as a fuel option for cars,” explains R. Andreas Kraemer, senior fellow at Institute for Advanced Sustainability Studies in Potsdam. “Hydrogen tends to explode violently. Thus the infrastructure for producing, storing, and transporting it has to be made out of intrinsically expensive materials. Yet there will still be a risk of explosion.” Hydrogen may be useful as an intermediary product in converting power to gas, and then to liquid fuels, says Kraemer, but this is still in the laboratories.