Solar powered tube trains for the future?

The tube trains of the future could get some of their juice from solar power, as Transport for London (TfL) is looking for a supplier who could plug solar cells directly into the TfL electricity grid.The project is primarily focused on private wire connections to new-build solar photovoltaic generation, and the contracts are for four years, with options to extend afterwards.
TfL has previously committed to delivering 1.1 megawatts of generating capacity by retrofitting solar panels across its la