Vehicle-Grid Integration (VGI)

Vehicle-Grid Integration is a broad term that covers all the different technologies and programs designed to use electric vehicles and their batteries as tools or assets to benefit the electric grid. When charging (or discharging) of EVs is coordinated with energy systems, it can create efficiencies that increase the adoption of zero emission renewable energy and electric transport, and reduce costs for drivers and energy consumers. 

Also known as managed charging, or smart charging, V1G can be implemented with a unidirectional, OCPP-integrated charger equipped with a charge management system such as ChargePilot®. V1G programs incentivize charging schedules to be shifted in harmony with supply and demand on the energy grid through programs such as time-of-use rates, demand response, dynamic rates, and demand charges. Using Flexible Interconnection (FIX) to defer grid upgrades at a site can also be considered a cost-saving V1G technique. 

V2G enables electric vehicles to both receive and deliver power back to the grid, supporting grid services. V2G requires a small generation interconnection with utility that authorizes a vehicle to discharge to a building, or directly to the grid. Once interconnected, EVs can also provide energy services such as solar self-consumption, time-of-use rate arbitrage peak shaving, and more in areas where utilities and system operators compensate for them. Providing these services to the grid can unlock new revenue streams for EV owners, creating a pathway to zero cost, zero emissions charging.  

V2X is an acronym for vehicle-to-everything, and includes all bidirectional charging use cases, including V2G, as well as vehicle-to-building (V2B) or vehicle-to-home (V2H) backup power applications. V2B/V2H is when an electric vehicle’s battery is used to power critical loads during a grid outage. This requires a bidirectional charger and transfer switch that is capable of completely disconnecting from the grid, or “islanding the site.” 

While a charge management system (CMS) such as The Mobility House’s ChargePilot® manages charging optimization for a fleet operator, Cascade can work with each CMS at thousands of sites to create flexibility for the distribution grid. 

The California Public Utilities Commission defines demand response as “reductions, increases, or shifts in electricity consumption by customers in response to their economic signals or reliability signals.” Electric utilities create demand response programs to allow customers such as electric vehicle fleets to respond to signals and receive incentives for participating. 

Most demand response programs require customers to participate by enrolling with an aggregator, so that the signals can be communicated and response can be verified. The Mobility House is a registered aggregator with California’s Emergency Load Reduction Program (ELRP), among other programs. 

Flexible connection expands upon site-level managed charging to apply charging flexibility to address distribution grid capacity challenges. When one or more sites within a distribution line are managing EV load precisely and effectively with a reliable CMS, this creates an opportunity for grid operators to address grid constraints at a substation level using flexible interconnections. By building on the CMS’ reliable and resilient EV load management capabilities at a site-level, the network effects of this control can be leveraged to avoid larger scale infrastructure upgrades at substation levels and participate in other grid stability functions such as demand response events. Utilities across the country are starting to develop pilot programs and regulations employing these controllable connections.