Changes to Britain's electricity trading rules should benefit small intermittent producers -- in particular wind -- who are unable to accurately forecast their output. The changes have moved wholesale trades of electricity closer to real time. Instead of suppliers having to bid the volumes of electricity to be traded 3.5 hours ahead of time -- or "gate closure," from early July they have been operating just one hour ahead. This reduces their exposure to hefty "imbalance charges" if they fail to deliver power as scheduled. The change is one of a series of measures that the wind industry has been calling for since before the country's new electricity trading arrangements were introduced in April 2001. David Still from the British Wind Energy Association reports, however, that the measure has so far had little effect on wind generators, who have mostly arranged sell their power to suppliers who consolidate the output within a portfolio of generation to reduce imbalances.