In many countries train companies are still paying for energy based on estimates, like ton/km or gross ton/km. These estimates do not always reflect the real energy consumption and can be manipulated.
Since 2014 energy meters on trains are mandatory in Europe. With this push from the EU Commission, all Infrastructure Managers need to get the tools to bill their train companies.

The tools are energy meters, a data collection system and a settlement system, like Erex, in place. With Erex system organizations can measure their energy consumption, improve efficiency, know and control their CO2 emissions and even regenerate the energy that trains haven’t used.
  
If you are interested to know more about Erex, please contact: jaccla@banenor.no