The most well-known solar configuration is grid-tie only. In contrast with hybrid and off-grid power systems, grid-tie only systems don't include batteries (which may be added later) and don't provide backup power (grid power must be available for operation). They are however, effective at reducing power bills with a lower equipment and installation cost than the more advanced systems.
As solar power is generated it is fed directly into the electrical panel where it is used by the loads (appliances) on the property, thereby reducing what would otherwise be purchased from the grid. Also, at times when more solar power is generated than is being consumed, the extra power flows to the grid. And when there is less solar power than needed, the grid makes up only the difference.
Since grid-tie only systems have no energy storage and therefore do not provide power at night time, the system is usually sized to meet daytime energy needs only. A larger system may reduce bills more, but increases the amount of excess power that will go to the grid. This all relates to the savings, economy of scale and best practice for system sizing.
Grid-tie only systems are a popular, simple and cost-effective option for being partially self-powered and realizing a quicker return on investment. We often recommend starting with a grid-tie system with the option to upgrade to a hybrid system in the future.