ON-Grid Grid-tied, on-grid, utility-interactive, grid intertie, and grid back feeding are all terms used to describe the same concept – a solar system that is connected to the utility power grid. THE UTILITY GRID IS A VIRTUAL BATTERY Electricity has to be spent in real-time. However, it can be temporarily stored as other forms of energy (e.g. chemical energy in batteries). Energy storage typically comes with significant losses. The electric power grid is in many ways also a battery, without the need for maintenance or replacements, and with much better efficiency rates. In other words, more electricity (and more money) goes to waste with conventional battery systems.