THE European Partnership for Railway Energy Settlement Systems (Eress) and its railway energy settlement system, Erex, is progressively making railway energy control possible across Europe. Seven countries are now signed up to the group, which provides energy metering services and enables the industry to accurately measure, control and bill for the energy consumed by trains.

Erex was first developed in 2004 by Norwegian infrastructure manager Jernbaneverket, Sweden's Banverket (now Trafikverket), and Banedanmark, and was primarily a Scandinavian concept designed to work across borders.

NE2Eress was subsequently founded in 2007 by the three Scandinavian infrastructure managers to expand the scope of the concept and promote data sharing, which has grown as new members have come onboard. Belgium's Infrabel (2012), as well as Finland's transport agency, Liikennevirastoits (2013), Swiss Federal Railways (SBB) (2014), all subsequently signed up to the organisation, and were joined by a seventh member in 2015, Vivens, a Dutch railway energy procurement cooperative which determines energy used by train operators in the Netherlands.

"The last twelve months or so have been exceptionally exciting for Eress, as we have seen a spike in the levels of interest in Erex across the continent," says Mr Dyre Martin Gulbrandsen, Eress director, who has led the development, implementation and daily operation of the Erex system for over a decade. "With the EU's ambitious 2020 climate and energy targets looming, we are making the case for Erex to become a European standard, managed at a European level, to transform cross-border standardisation from a pipe dream into a reality."

The need for Erex is readily apparent. Currently in many countries railway operators are invoiced with an estimate for the amount of energy consumed, using simple measurements involving the weight of the train and how far it travelled to come to a vague figure. Invoices are often exorbitant, and operators have no way of knowing whether they are accurate - or even close.

"The lack of accuracy in invoicing and billing also means there's no incentive for train companies to save energy, as they don't see the benefits of reducing energy usage when invoices are created using these calculations," Gulbrandsen says. "For these operators, it seems almost futile to prioritise energy efficiency when they won't see any of the rewards for doing so."

Erex is overcoming this problem by acting as an energy settlement system. It receives measured energy data from most of the existing energy measurement systems active not just in the partner countries but across Europe as well as data from GPS positions, train management systems, and the specific energy prices per hour and for a certain country. From this it validates, filters, and combines all of the information to ensure that the data is correct before it becomes the basis for billing the operator when operating in a specific territory. Both infrastructure managers and train operators have access to their own data via the web portal at, email, and a set of reports, which provides a transparent process.

With a new set of standards and regulations working all over Europe such as the Directives, TSIs, Cenelec norms and UIC Leaflets, active cross-border use of the Erex system is made possible. Under Erex, energy consumption is measured minute-by-minute or at five minute intervals, depending on national requirements set by the infrastructure manager. As a result train operating companies pay exactly for the amount of energy they use, at the right time and at the right price, and this gives them a huge incentive to reduce their energy consumption across the board.


Since installing Erex in 2004, Norwegian State Railways (NSB) has saved e37m in energy consumption costs, and is now using approximately 75% of the energy it was consuming 12 years ago. In addition, in the past year Erex has increased its performance significantly to the extent that it is now able to handle most of Europe's existing and expanding train fleet. Currently more than 4000 traction units are using Erex and Gulbrandsen says this is expected to double in the next five years.

Recent trials with Erex also show the advantages of the system. In Belgium, railfreight operator SNCB Logistics has successfully reduced the annual energy consumed by freight trains by 25%. The trains which participated in the test also received 72% less double yellow or red flags, which significantly improves rail safety. French National Railway (SNCF) confirmed in 2015 that it will engage in similar tests with Erex on 50 of its freight locomotives, while in Britain, Virgin Trains is currently trialling the system.

Erex is also playing a role in clarifying energy transmission and billing between countries. French locomotive leasing company, Akiem has spoken of the problems it has experienced transmitting, receiving and validating data between French and German infrastructure managers. Erex managed to solve the problem, with DB Energy, which is now also providing metered traction energy data for billing purposes, confirming the system's effectiveness.

At the 2015 Annual Eress Forum held in the Netherlands, Gulbrandsen says there was a "unanimous consensus" that Erex is, or should become, the "de facto" standard settlement system across the continent and that Eress may not be too far away from this goal. He also expressed his desire to attract more members.

"Fortunately, European legislation is currently leaning in our favour when it comes to installing metering systems on trains, but at the moment operators engaging in this type of energy measurement seem to be the exception rather than the rule, and we want to make precision metering and settlement the norm," Gulbrandsen says.

One of the key immediate ambitions for the team at Eress is to facilitate increased data sharing among all seven of their existing partner-countries. This is seen as a fundamental step in ensuring progress, improved performance, and stronger partnerships among all members.

Gulbrandsen says that the Eress partners have been instrumental in developing the solution's basic functionalities and increasing performance over the years, with data sharing paramount to continuing improvement.

"Energy metering is just the tip of the iceberg," Gulbrandsen says. "We have a collective spanning seven countries, with great power and reach as a group. We can discuss and work together on a multitude of topics regarding energy-efficiency, not just railway metering."

The vision for Eress members is to pool ideas and resources into the organisation rather than compete with one another, with information shared potentially leading to refinements and enhancements to the benefit of all involved. The group's annual forum, which was held in Madrid on May 25, aims to do this by inviting member and non-member countries' infrastructure managers and operators, as well as organisations like the European Railway Agency (ERA), European Commission (EC), International Union of Railways (UIC), Community of European Railways and Infrastructure Managers (CER), European Rail Infrastructure Managers (EIM), International Energy Agency (IEA), and universities to discuss the concept.

In the short-term, the goal for Eress is to continue developing its technology, for example by adding a comprehensive data collection system to Erex, so meters installed on trains can feed energy directly into Erex. With more operators involved and thousands of train journeys measured every day, those concerned with railway energy consumption can gain a complete picture of how much energy is consumed and what should be done in order to reduce these levels for the good of the entire continent.