A grid-tied solar power system, also called a "grid-connected" or "utility-interactive" system, powers a building while remaining connected to the electrical grid. The main goal of this setup is to offset the building's grid electricity usage, helping to lower electricity bills.
Most solar power systems, including inverters, are designed to work with a grid connection, with or without battery storage.
Key components of a grid-tied solar system include solar panels and a grid-tied inverter. Together, they generate electricity from sunlight, supply it directly to the building, and send any surplus power back to the grid. This arrangement allows homeowners or businesses to use their solar-generated power and rely on the grid for any additional needs or to sell excess energy back.
To maximize benefits, the solar panel array should ideally be sized to match the building's average daytime energy use, typically covering about 25-50% of total consumption. Solar power used as it’s generated—during daylight hours—provides more savings than selling it to the grid. Homeowners can further optimize solar usage by running appliances during the day to reduce grid reliance.
Since a grid-tied system is connected to the electrical grid, an interconnection agreement with the utility company is required, along with a bidirectional meter to monitor energy flowing to and from the grid. Monthly, this setup lowers the energy charge for usage and provides a small credit for the excess solar power feeding back to the grid.
While batteries are optional for grid-tied systems, they have become more popular due to decreasing costs and added benefits, such as backup power during grid outages. Batteries can also enhance the system’s effectiveness in reducing electricity costs.