DESC0023916

We propose a fundamentally new balance of plant (BOP) architecture for a PV solar system integrated with battery storage and heavy-duty EV fleet charging infrastructure. These PV solar systems are 1- 10s of MW in size, with a 2 to 4-hour battery and several MWs of EV charging electronics. Usually known as microgrids, these integrated PV systems connect to the bulk power systems, providing resiliency and grid reliability services while performing the primary function, for example, heavy-duty EV charging stations for fleets such as buses, freight trucks, etc. The market analysis indicates several GWs of such systems are necessary to support the electrification of EV fleets while increasing the reliability and resilience of utility grids. Proven technical solutions exist to implement such PV solar systems with battery and EV charging subsystems. The problem is that these isolated subsystems often result in a cost-prohibitive system with a lower utilization factor for each subsystem. The other problem is grid interconnection and permitting, which is notably more problematic for heavy-duty EV charging infrastructure. Furthermore, despite battery storage integrated with PV, the resiliency and reliability are questionable – forcing most installations to require diesel generators as a backup. We propose a fundamentally new system architecture for PV solar that reduces the BOP and construction costs by over 30%, enabled by the proposed modular solar-storage building blocks. Furthermore, the innovation in BOP architecture requires only 35% BOP hardware to facilitate 100% rated EV charging. Other differentiated features are: • Unmatched resiliency: For example, with a dc-coupled 300kW V2G hardware onsite, an electric bus or truck can black-start a 1-100MW PV site. This feature is analogous to a portable generator black-starting a PV plant during weather-caused grid outages. • Unmatched safety: fire-safe system (yet based on mainstream Li-ion battery cells) with no chance of fire-propagation from an internal or an external cause of the fire, enabled by the proposed BOP and thermal management technologies. • Lower soft costs: the proposed architecture based on dc coupling requires no upgrades on ac side, requiring utility upgrades no more than needed for the PV system only. We plan to prove the feasibility of the technology by building R&D prototypes in the SBIR phase-1 round. Phase-II will focus on building manufacturing-grade product prototypes and validating the technology in the field.