Transmission charges should be based on the average capacity that can be depended upon from a power source, including that of intermittent renewable sources such as wind, solar and hydro. That is the conclusion of a report by Tellus Institute, a non profit think tank in Boston and commissioned by the American Wind Energy Association. Use of wind would be encouraged if utilities used this concept of "equivalent capacity." The report authors, Richard Rosen and Stephen Bernow, say their proposal would mean, for example, that a 100 MW wind farm with a 30% capacity factor would only be charged for the equivalent capacity of 30 MW. Concerns about wind's competitiveness as an intermittent source of clean power are increasing as the power market is deregulated. Transmission pricing is vital as independent producers and utilities are increasingly being charged for wheeling and network service, where a utility charges for transmission within its own system. The report was issued on September 26.