An efficient use of the fluctuating energy output of photovoltaic (PV) systems requires reliable forecast information. In fact, this integration can offer a better quality of service if the solar irradiance variation can be predicted with great accuracy. This session elicits new research on the methods used to forecast solar irradiance in order to facilitate selection of the appropriate forecast method according to needs. The methods could include statistical, artificial neural network, cloud motion vector, numerical weather prediction or some combination of these methods.