TOEFL 통합 작문

📖 읽기 지문

The introduction of the electric road system (ERS) for heavy-duty trucks has been proposed as a sustainable solution to reduce greenhouse gas emissions in the freight sector. ERS involves equipping highways with overhead wires or embedded rails that supply electricity to trucks via a pantograph or inductive pickup, allowing them to operate like trolleybuses on major routes. Proponents argue that ERS offers three major advantages. First, it is energy-efficient: direct electricity from the grid avoids the multiple energy conversions (e.g., from electricity to hydrogen or battery charging) that other alternative fuels require, thus reducing overall energy loss. Second, ERS reduces battery weight and cost: trucks can use smaller batteries because they draw power from the grid while on equipped highways, and only rely on batteries for the last miles to their destinations. This not only lowers vehicle purchase costs but also increases payload capacity, as less weight is devoted to batteries. Third, ERS is scalable and future-proof: as the electricity grid becomes greener, the emissions from trucking will decrease automatically without requiring changes to the vehicle fleet. Furthermore, the infrastructure can be expanded incrementally, starting with high-traffic corridors, and once in place, it can serve multiple truck manufacturers if standardized.

🎧 듣기 강의

The professor challenges each of the points in the reading. First, while the reading claims ERS is energy-efficient, the professor notes that the infrastructure itself requires enormous energy inputs for construction and maintenance. Building overhead catenary lines or embedding rails in concrete for thousands of kilometers involves significant cement and steel production, which are highly carbon-intensive. Moreover, the transmission losses from power plants to the grid and then to the trucks are not negligible, especially over long distances, and these losses are often overlooked in the reading's comparison. Second, the professor argues that the claim of reduced battery weight is misleading. Trucks still need large batteries for routes that are not covered by ERS, which may include most of the network initially. In practice, to ensure flexibility, trucks would need batteries sufficient for at least 100-200 km, which still adds substantial weight and cost. Additionally, the pantograph system adds mechanical complexity and weight, partially offsetting the savings. Third, the professor disputes the scalability and future-proofing argument. The infrastructure is highly specific to roads equipped with ERS, and if the grid decarbonizes, it would be simpler to use that clean electricity to produce hydrogen or synthetic fuels that can be used in existing trucks, without the need for massive roadside equipment. Moreover, standardization across manufacturers and countries is difficult to achieve, and the rapid advance of battery technology may soon make ERS obsolete, meaning the investment could become stranded. Therefore, the reading's optimistic view is overly simplistic.