1. A system comprising: a platform apparatus; and an on-site gateway apparatus, the platform apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the processor, cause the apparatus to: calculate site load curves indicating predicted site load of a customer at each of a plurality of periods of a day as a function of one or more of historical meter and billing data, in consideration of other existing on-site generation resources, and market or weather data, for each of one or more customers with on-site energy assets within a given portfolio aggregation; perform portfolio-level optimization as a function of the site load curves and a tariff library, the portfolio-level optimization configured to segment the site load curves in accordance with tariff periods and other site-level restrictions, and for each segment, calculate and output a power consumption maximum threshold; generate a set of site-level schedules, as a function of the portfolio-level optimization and one or more site restrictions, the set of site-level schedules configured to be provided to a gateway apparatus for facilitating the use of the on-site energy assets instead of grid-supplied electric consumption; and the gateway apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the processor, cause the apparatus to: receive the site-level schedule from the platform device and store that site-level schedule locally; at a start time of a given segment, provide instructions to facilitate real-time or near real-time on-site asset control.