Power generators across five European countries are likely to reap €71bn ($112bn, £56bn) in windfall profits in the next four years as a result of the European Union's emissions trading scheme, according to a report.

Power companies are given most of their permits to emit carbon dioxide for free, but can pass on to consumers the notional cost of having to buy the allowances. According to the report, commissioned by the green campaigning group WWF from the carbon market analyst company Point Carbon, the resulting windfall profits to power companies in the UK, Germany, Spain, Italy and Poland would reach €71bn over the second phase of the scheme, from 2008 to 2012, if the price of permits reached €32 per tonne. It is currently about €23.

Fiona Harvey, London