Energy meters have two positive effects on energy efficiency which presumably are both substantial but difficult to quantify:

Economic incentive

If energy billing is based on calculations, there is no economic incentive for operators to save energy by recuperation or energy efficient driving. Consumption data collected in the TEMA project at DB AG show that the energy consumption on a given line differs by up to 20% from one day to another. This underlines the role of factors such as weather, track conditions, traffic situation or driving style for energy consumption. These conditions are not taken into account by simulations presently used. Often, the calculated energy consumption is not even accurate enough to provide an incentive for using energy efficient stock. These shortcomings of theoretical consumption data obviously don’t apply to on-board energy measurements.

Monitoring of energy saving measures

Measuring or calculating energy consumption in itself does not save energy. However a better knowledge of energy consumption will provide valuable data to identify potential for optimisation as far as regenerative braking, energy efficient driving or stopping patterns are concerned. Experience at DB AG shows that energy meters facilitate the monitoring and thus tend to improve the general acceptance of energy saving measures within the company.