Their argumentation is pretty naive. If they would truely like to fix up the situation, they could simply put a tax on the exported electricity. Depending on the height of the tax, exports would be adjusted accordingly. Maybe, a non linear taxation scheme would be needed to allow exports in normal operation states and prevent exports in high price situations.
They might be able to tax the exports to the UK but not to the EU. As a member of the European Economic Area, Norway cannot impose trade barriers within the single market.
