An innovative water power plant has opened near Oslo: It produces power using the different salinities of sea and fresh water. The so-called osmotic power plant is a joint project between energy company Statkraft and several European research institutes.Unlike wind and solar power plants, the emissions-free system does not depend on weather conditions. In the future, the prototype could be used to construct osmotic power plants in any location where both freshwater and saltwater resources are available, such as the mouth of a river.   Report by Mabel Gundlach