V2G - Vehicle to Grid

Interconnecting an EV to the grid and the ability to charge and discharge a battery for for grid services, turning the vehicle into a Distributed Energy Resource (DER) while it's parked. These grid services can include wholesale market operations like frequency regulation and real-time pricing or distribution level services like Demand Response (DR). 

V2H - Vehicle to Home

This is a residential application to use an EV at home. The energy services are poorly defined here, but most people assume of emergency back up power as the main function (even though many EVs and products can't peform this function). 

V2B - Vehicle to building

Not a well defined term, but refers to commercial building applications which required higher power and different voltages. It also suggests energy services typical for commercial accounts such as demand charge management (DCM) and Time of Use (TOU) rate arbitrage, but this is not clearly defined either. For some reason many people assume this is less complex than V2G, but requires all the same certification, functionality and interconnection, causing this acronym to do more harm than good. 

V2L - Vehicle to Load

This is using the vehicle as a power source for an independent load like power tools, appliances or other systems not connected to the grid. Think of this like plugging something into to your cigarette lighter but being able to get 100x the power out of it. 

V2X - Vehicle to Everything

This is supposed to encompass all these variations, but usually gets confused with with C-V2X, the vehicle to infrastructure technology that refer to systems that connect vehicles with street lights and other traffic systems. 

VGI - Vehicle Grid Integration

This is a California invented term that encompasses all aspects of a vehicle connected to the grid. In short, V1G and V2G is VGI.

V1G - Smart charging

Unidirectional charging. This is insider jargon as a play on words the acronym V2G. Only controlling the charge rate, not discharging the vehicle

V2V - Vehicle to Vehicle

Sharing energy between vehicles.

VTG - Vehicle to Grid

I’ve seen European colleagues use this instead of V2G. Perhaps V2G only works well in the English language. 

ePTO - Electric Power Take-Off

Similar to V2L, but usually for Heavy Duty vehicles, and not limited to an EV.

BPT - Bidirectional Power Transfer

Used in standards langauge 

Other associated terms

Islanding - the ability to disconnect from the grid and power a home independent of the distribution utility.

Blackstart - an additional battery that can "turn on" a V2X system on in a power outage.

Interconnection - Approval from the utility to be connected to the grid. This is required even if power is not planned to be exported. A customer is required to obtain a PTO (permission to operate) from the utility if a battery will be connected to the grid. 

EVSE - Electric Vehicle Supply Equipment

Fancy word for charging station, as the actual charger may be inside the vehicle or inside the EVSE. See below.