Solar systems can be used for homes, offices, public buildings, car parks or remote sites. They can be installed on roofs, terraces or on building facades or operate as stand-alone systems. A photovoltaic (solar) installation can be either connected to the electricity grid (so called grid connected) or stand-alone (off-grid). The former one could allow any excess electricity production to feed the electricity grid and to sell it to the utility company. In Colombia this option (called net metering) is now a reality thanks to the recently enacted Law 1715 of May 2014.
Off-grid or stand alone photovoltaic installations have no connection to an electricity grid, and are contributing to rural electrification in many developing countries. These stand-alone systems have a storage battery for supplying the electric energy when there is no sunlight.
