SBB trains are powered by electricity generated entirely from renewable sources, as certified by guarantees of origin (GOs). 

Before now, hydropower was responsible for around 90 percent of the power used to run SBB trains, with nuclear energy accounting for the remaining 10 percent. Today, SBB is no longer using the electricity from its stake in nuclear power for rail operations but is instead selling it on the electricity market. It is also purchasing an equivalent amount of renewable energy, primarily from hydropower plus solar and wind energy, from Switzerland and the rest of Europe on the electricity market.

Rail has always been a green mode of transport. 

Rail travel has always been environmentally friendly. In fact, rail is the most climate-friendly mode of transport after human-powered mobility. Rail travel causes only 0.3 percent of the total CO₂ emissions generated by transport in Switzerland. To move 17% of passenger traffic and 38% of freight traffic, rail transport uses just 5% of the energy consumed by road transport in Switzerland. 

A major step towards achieving sustainability objectives. 

The transition to 100 percent renewable rail power is part of SBB’s sustainability strategy. To contribute to the Paris Agreement, SBB aims to halve its operational greenhouse gas emissions by 2030 compared to the base year of 2018. SBB aims to cut over 90 percent of its greenhouse gas emissions by 2040. To achieve this, SBB is saving energy, focusing on renewable energies and the circular economy, and replacing climate-damaging technical gases with more climate-friendly alternatives, such as more environmentally friendly refrigerants for air conditioning on trains.