Trains in Switzerland Are Now Running Over Solar Panels in a First-of-Its-Kind Test
(www.zmescience.com)
Switzerlands rail network is around 5300km long (source) if you cover around 50% of it, that gives roughly 500MWp installed capacity. A modern locomotive has 4-8MW. That gives you enough energy to power 80 locomotives under full load. I expect them to use much less power once in motion so it may be more in reality. That’s not nothing.