ProsumerGrid, Inc. was engaged by the Innovation Alliance Renault Nissan Mitsubishi to perform a feasibility study to determine the optimal portfolio of energy supply options for a large electric vehicle (EV) charging facility referred to as EV-Hub. With the increased level of EVs and electrification in the transportation sector, EV hubs will become necessary for large EV fleet operations. Energy supply will be a critical economic decision for these EV hubs and an optimal design of energy supply can provide many benefits, increased reliability and lower overall cost, while meeting strategic objective and requirements. In this project, the strategic objectives and requirements were identified as:
- Economic requirements: The optimal design should minimize the total capital and operational costs of the energy supply for the EV Hubs which is very important given its major impact on operational expenses.
- Resiliency/Reliability requirements: Resiliency/Reliability of the energy supply is critical to meet the EV charging time requirements and operations. Grid outages and disconnections can impact the operation of the hub and its impact should be minimized.
- Sustainability requirements: Sustainability and consideration of emissions and incentives are important for long-term value of the project energy supply options.
The analysis uses the ProsumerGrid’s Software that is based on advanced optimization models that select the optimal types of energy resources and their sizes from a defined input set of energy supply options to meet the expected electric load profile over a multi-year (this study was eight (8) years) planning horizon and at a very fine granular resolution (the study was ten (10) minutes) while meeting the above requirements and strategic objectives. These requirements are translated into monetary values in the project capital and operational costs and the optimization model minimizes the total costs. The study determines the optimal energy supply options and their sizes from a set of broad distributed energy resource (DER) technologies and local grid energy. The DER options included:
- Distributed generators including natural gas generator and diesel generator
- Solar PV
- Energy storage technologies including new and used (2nd life) Li-ion batteries, lead acid batteries, sodium sulfur storage and supercapacitors
- Demand response including the flexibility in the demand
- Fuel cells