So far, U.S. ISOs/RTOs are apparently focusing on how to integrate the information in wind power forecasts into the reliability commitment. This is obviously important to address reliability, and the reliability commitment will also influence RT prices. However, it is also important to integrate the information in wind power forecasts into the DA market clearing. Wind power will have an increasing impact on the marginal cost of electricity and this should be properly reflected in the DA market clearing, where most of the energy is settled. An important challenge is how to consider the uncertainty information in the wind power forecast in the DA operating procedures. An interesting approach is taken by ERCOT, which is currently using an 80% exceedance forecast for wind power generation as input to their DA resource planning procedures (Maggio 2009).