I have solar power and sometimes can charge car up with it…..its not easy to do though because the sun needs to be shining and the car needs to available for charging.
My solar pv on its best day can produce 50kw of electricity, however for 200 days a year it will produce less than 20kw, the I3s battery is 42kw so I don”t count on solar panels for charging. That said a cheap overnight tariff plus solar delivers cheap fuel.
One other consideration for v2g is would you want to risk your 40-50k ev for a few £’s of electricity going into home? Battery life, vehicle warranty etc?