This study reviews alternative energy technologies and systems to fossil-fuel based transportation, and assesses both technological and energy views in future scenarios. Researchers estimate the energetic cost of the transition from the current transportation system into a global 100 percent renewable transportation scenario including the quantity of electrical energy required.
The authors discuss main proven technologies for each transportation sector, and new infrastructure and policy measures associated with a transition strategy to renewable energy according to feasibility and sustainability criteria. Energy and monetary expenditures associated with the future scenario were computed, including conservative estimates of variables such as efficiency of new transport systems and costs of the new transportation fleet.
In order to forecast impacts associated with a 100 percent renewable energy transportation system, researchers identified the expected composition of each transportation sector including each mode. The analysis focuses on the energy impacts due to changes in each component and includes consideration of variations such as type of fuel.
- A 100 percent renewable energy transport system providing the same service would demand about 18 percent less energy overall. The main reduction is due to an expected 69 percent lower energy consumption in road transport.
- However, the shipping and air sectors are forecasted to notably increase their consumption, by 163 percent and 149 percent, respectively. In particular, overall estimates appear highly sensitive to fuel assumptions for air transport (hydrogen vs. renewably-sourced methane vs. jet biofuel).
- The study notes that certain factors such as new technologies and geo-political changes are highly unpredictable and could significantly affect any forecasted estimates.
- The analysis concludes that a 100 percent renewable transportation system is feasible, but may also be constrained by scarcity of critical supporting materials.
Volume 158, 15 February 2018