Cars capable of supplying electricity back to the power grid are often referred to as "Vehicle-to-Grid" (V2G) vehicles. As of my knowledge update in September 2021, there are still not many cars on the market that are standard equipped with V2G functionality.

V2G technology enables electricity to be supplied back to the grid from the vehicle when the car is connected to a charging station. This can help balance the power grid, reduce peak loads, and enhance the integration of renewable energy.

Although V2G functionality is currently still limited, pilot projects and trials are being conducted to explore and develop the possibilities of V2G. In the future, we may expect more cars capable of supplying electricity back to the grid.

It is advisable to contact car manufacturers and authorized dealers for the most up-to-date information on specific models and the availability of V2G functionality.