The Geoelectric Field is a measure of the induction hazard to artificial conductors, such as electrical power lines, that results from Geomagnetic Activity, and can be used to estimate the amount of current induced by integrating along the conducting pathway. Potentially hazardous geoelectric fields can be induced during geomagnetic storms. These geomagnetic storms are a form of space weather driven by enhanced currents in Earth's magnetosphere and ionosphere and are observed at ground level as a time-varying magnetic field. As is well known from Faraday's law, a time-varying magnetic field induces currents along natural and artificial conducting pathways. This geoelectric field product combines information about the time-varying magnetic field together with available Earth-conductivity information to estimate regional geoelectric field levels on a geographic grid over the lower 48 states. The near real-time E-field mapping project is a joint effort between NOAA/SWPC, the USGS geomagnetism group, and the NASA/CCMC.