The International Energy Agency (IEA) is calling on countries to do more to reflect renewable energy's environmental benefits in energy prices. In a new report "Renewable Energy Policy in IEA Countries -- Volume II: Country Reports," the IEA criticises the lack of progress to date in this area despite the negative externalities associated with conventional energy forms. It warns of difficulties in increasing renewables' share of electricity generation while at the same time moving towards fully liberalised power markets. Competition on cost grounds alone will disfavour renewable electricity, the report says. It points out that moves towards liberalisation are already affecting policies for promoting renewables. Competitive bidding mechanisms within a ring-fenced market -- such as the UK's Non-Fossil Fuel Obligation -- are becoming more common, with France and Ireland both adopting similar schemes. Green pricing -- where consumers opt to pay more for renewable electricity -- has become more popular in parts of the US and northern Europe, but has still made little overall impact. The IEA would like to see countries do more to offer consumers the choice to buy green power.