Primary load is the electrical load that the system must meet immediately in order to avoid unmet load. In each time step, HOMER dispatches the power-producing components of the system to serve the total primary load.
Click either the Electric #1 or Electric #2 button to open the Electric Load Set Up page. The details of a load in a given system are sometimes not available, so HOMER can build (simulate) a load in several ways (see Adding a Load). After HOMER creates the load, you can edit it in several ways, including modifying individual time steps.
After you have added a load, you can make changes on the Electric Load page. See the Load Profile section of the help.