A large number of early V2G pilots are focused on electric cars. However electric buses with large batteries are also good candidates for V2G.

I would think buses are a great place to start not just because of their larger size but their greater predictability in time/place of charging. From there, perhaps the next step is large corporate or government fleets of smaller EVs, where you can still sign on a big contract and have an aggregate predictability that's less achievable with people's person vehicles. 

Chandana, yes the potential for V2X is great. The new batteries are getting better and lower in cost. They will last longer than the vehicles they are in. So why not let them earn their keep and help the GRID and or the needs in a power outage. It's a great opportunity.

   Combining this storage with renewable Solar PV , Wind and Hydro is a perfect solution. 

     I worked in Mumbai india for a year. The wires on the poles and towers along the streets were very messy. I heard about a lot of power theft. It was said to be 10 to 20% lost. How can that and other GRID  problems be solved? 

"Can I use my EV to offer support to the uptake of renewable energy? Can I use my EV when it is parked to earn money through the support I am offering to the power grid? Can I..."

Chandana, the first question to answer should be: "When almost half of energy stored as V2G is wasted as heat from resistance and bi-directional inversion losses, is adopting the technology 'to offer support to the uptake of renewable energy' not creating more carbon emissions than it's saving?"

In their eagerness to promote renewable energy, many advocates lose sight of the prize: lowering carbon emissions. Charging an EV from a grid with any carbon-emitting generation at all will result in a carbon impact at least 40% worse than had V2G been avoided.