Certainly possible. The Tesla Roadster's bodyweight is approximately 1,200 kg, the current Light-Sport Aircraft regulations (which is equivalent to most countri

Certainly possible. The Tesla Roadster's bodyweight is approximately 1,200 kg, the current Light-Sport Aircraft regulations (which is equivalent to most countries Ultralight regulations) put a vehicle with a max take-off weight at 600kg. Ultra-light engines are typically in the 80hp-120hp region, so it certainly looks plausible. I'm sure, if you stripped down a Tesla to bare necessities (IE no crash protection) the weight to horsepower ratio will be even better. So I wouldn't doubt you'd be able to make a fully electric airplane that is capable of flying a fair distance. In fact, fuel efficiency in airplanes can be better than most cars. Again the fuel efficiency can also be affected by the parts used (obviously li-ion would be the minimum, lead-acid would either weigh too much or you'd plummet to your death after 5 miles) and thin-film PV cells could easily be applied to a plane's broad wingspan, however this likely wouldn't increase the flight distance much (even with 100% efficiency and optimal conditions, your average ultra-light wingspan wouldn't ever produce the total power needed for a 80HP/60KW motor).