HVDC power transmission is now being considered not only for point-to-point interties, but also as true grids where several operators may tie into the grid, each having its own economic sphere. In this new situation, it is important that transmitted energy be distinguished from losses incurred in the converter stations, to enable a fair distribution of costs for grid operation. To this end, a metrology infrastructure is needed where high-current and high-voltage transducers must be possible to calibrate traceably, and where dc electricity meters can be calibrated and approved. A research project is currently working with these questions in a concerted European research effort, funded by the European Commission. The present publication highlights important aspects of this work.