Sheffield Solar, a project initiated by the Department of Physics, University of Sheffield, United Kingdom, has been successful in forecasting the energy generation levels for photovoltaic (PV) projects up to three days in advance. The technology will help provide advanced knowledge of the PV output, allowing operators to make more efficient use of the reserve capacity from storage or conventional generation sources. The team has previously worked with the national grid on a tool that estimates the real-time generation from PV systems. This technology is a step forward as it combines live output data with weather forecasts in order to accurately estimate the future output. Sheffield Solar also has plans to provide forecasts on a regional basis and for individual PV systems.