In this new world of connecting electric vehicles to the grid, there is a lot of jargon created that makes sense to everyone working on it at the time, but tends to confuse everyone else not involved.
Throughout this website I use V2H for simplicity and because it's my favorite application.
Here is an overview of the different terms you may run into and how they differ
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
AC-V2G vs. DC-V2G
V2H can get very confusing as there is more than one way to export power from an EV. Batteries store electricity as Direct Current (DC), but our homes and buildings use Alternating Current (AC). That means the battery needs an inverter to be useful. That inverter can sit inside the vehicle as an onboard charger (OBC) or can sit inside the charging station.
AC-V2H refers to a bidirectional onboard charger inside the car.
DC-V2H refers to a bidirectional charging station (or EVSE).
This is imporant, as the inverter is the point of interconnection with the districtuion utility. In the US, most utlities are looking for a safety certification called UL 1741 in order to approve interconnection. Charging stations can get the certification; the industry is still working through how a vehicle could obtain an equivlent certification. This means the main commercial offerings will be DC-V2H for the next few years.
Where the inverter is located matters a lot
US Charging Standards
How you connect to the EV battery happens through the charging connector. Here are the main connectors and protocols in the US. Recoginize there is a commuinication protocol as well as a plug type that is important for V2H.
World of their own and will sell you a Powerwall instead of V2H functionality. No V2H functionality and not planned.
This is capable fo V2H and the dominant charging standard in Japan and fading from US and EU
Becoming the dominant charging connector in the US, but different version of the charging protocols are currently being used for V2G. In the US these are the standards being implemented for V2G with CCS
The standards bodies working with CCS have been extremely slow on adding V2G functionality. Surprising it has taken these groups so long as CHAdeMO had this enabled more than ten years ago.
This is possible to export power via AC, but additional communcations is required. See above for issues of interconnection with and AC system