Abstract: A centralized modeling system is implemented via a host server that is accessible to a large number of clients (organizations) using a website. In one example, it is assumed a client wishes to reduce its CO2e emissions by reducing its energy consumption by a certain amount per year. The client then enters a budget, and the server or client identifies a list of all the possible initiatives (specific projects) for electricity reduction. The client enters certain relevant information to customize the initiatives. The server may then automatically calculate, using conversion factors, each initiative's cost and estimated electricity and emissions reduction per year, among other metrics. The software allows the client to repeatedly select any combination of the initiatives and then models the resulting total energy savings and CO2e emission reduction, and any budgeted amount remaining. Based on the modeling, the client then decides on the overall strategy using a combination of the initiatives.