the balance of the overall generation portfolio as well as the potential costs of environmental externalities that may have to be paid in the longer term should always be an integral part of the discussion whenever countries negotiate with donors on investment in new assets although international coal prices have risen dramatically over the past decade the direct costs of coalfired generation are often low compared to other sources especially if the coal can be used close to its source reducing transport costs political economy considerations may well prevent sufficient compensation being paid to developing countries to incentivise them to leave these resources in the ground