At the moment, there are several electric cars on the market that offer the possibility to feed energy back to the power grid, also known as vehicle-to-grid (V2G) technology. Although V2G is not yet widespread, there are some car models that support this functionality. Some examples are:

1. Nissan Leaf: The Nissan Leaf is a popular electric car that offers V2G capabilities. Using a special V2G charging cable and a V2G-compatible charging station, the Nissan Leaf can feed electricity back to the grid, contributing to the stability of the power grid.

2. Mitsubishi Outlander PHEV: The Mitsubishi Outlander PHEV (Plug-in Hybrid Electric Vehicle) is a hybrid SUV that also supports V2G functionality. With the right equipment, the Outlander PHEV can be used to feed energy back to the grid.

3. BMW i3: The BMW i3, a compact fully electric car, has the capability to participate in V2G programs. With the right V2G equipment, the BMW i3 can feed electricity back to the grid.

It is important to note that the V2G functionality is often optional and specific equipment and charging infrastructure are required to make it possible. Additionally, the availability and compatibility of V2G technology may vary depending on the country and specific market.

If you are interested in using V2G technology, it is advisable to contact car manufacturers or charging infrastructure suppliers to inquire about the possibilities and availability of V2G functionality for specific car models.