In HOMER documentation, the word system refers to the combinations of technologies and components of a power generation system. The terms system type and system configuration have different meanings that are described below.
A system type is a combination of technologies. For example, wind/diesel/battery describes a system type that includes wind turbines, diesel generators, and batteries.
A system configuration is a combination of particular numbers and sizes of components. For example, a system with a generic 10 kW wind turbine, 15 kW diesel generator, 32 batteries and a 6 kW inverter describes a configuration of the wind/diesel/battery system type. The same system type with 48 batteries is a different system configuration.
HOMER simulates system configurations. As it searches for the optimal system type, HOMER typically evaluates hundreds or thousands of system configurations. HOMER displays a list of system configurations in the overall optimization results table, and the most cost effective configuration of each system type in the categorized optimization results table.
A system configuration can also be defined by dispatch strategy. For example, a system consisting of a generic 10 kW wind turbine, 15 kW diesel, 32 batteries, and an inverter could have two configurations: one with a load following dispatch strategy, and another with a cycle charging dispatch strategy.