Abstract: In an embodiment, measurements are simulated of direct normal irradiance, diffuse horizontal and global horizontal irradiance from groups of two or more photovoltaic arrays and/or irradiance sensors which are located in close proximity to each other and which have different tilt and azimuth angles. Irradiance measurements derived from solar power system power measurements are combined with measurements made by irradiance sensors to synthesize an image of ground level global horizontal irradiance which can be used to create a vector describing motion of that image of irradiance in an area of interest. A sequence of these irradiance images can be transformed into a time series from which a motion vector can be derived.

Abstract: A method for hedging energy sales or purchases in a short-term future or day-ahead market includes determining an historical performance of a regional net energy forecasting methodology for a facility or facilities which have solar energy generating systems in a geographical region. The method further includes estimating a difference between the maximum cost of energy in a spot market and an energy trader's minimum price of energy for each hour bid in the short-term future or day-ahead market, determining a risk factor associated with energy sales or purchases from the historical performance and the estimated difference, and purchasing or selling options to buy energy at the previous day's day-ahead market price based on the determined risk factor.