But really the best option is an electric car running on solar/wind generated electricity. Electric cars have a range of 400Km+ which compares well with petrol powered cars. The Tesla model S has a range of up to 500Km depending on the test cycle used - my personal record for driving a car without refuelling is 500Km.
The other problem with full electric cars and that is not mentioned as often as range is recharge time. For an electric car to be really practical a few things would ideally need to happen. 1. range to equal or exceed drivable distance during day time say at 100 kms/hr, say for 10-12 hrs = 1000kms to 1200kms, but probably closer to 1500kms to account for load variation. Then one could realistically drive all day and recharge overnight. Thats assuming recharge time 1hr = 1r driving. Or 2. Recharge time to e substantially reduced to say 1 hr = 8-10 hrs driving. Then you could drive for say 4 hrs stop for 1/2 hr recharge and drive another 4 hrs etc ... 3. You could also have a quick battery replacement mechanism, (like swapping your bbq gas bottle), where you basically pay for the charge + a small admin fee. 1. above is probably the most likely scenario to be available sooner than later. I read recently (will have to find reference, unless someone else has it handy?) that 800kms range electric cars is not too far away so thats a 100% improvement on the current ~400kms. All the above assume that people use/own their car as they would use/own a petrol car. But other factors come into play. Cost of electric cars: They are still quite more expensive, although prices are coming down. Car ownership: What do people expect and how do they use their car? Although by far the majority of car trips done by someone owning a car (specially private owners) would be daily commute for work/domestic purposes and would most likely fit in the 400 kms range, people would still want prefer a car that can easily do the "few times a year" 500+ kms holiday trip from Melbourne to Sydney or similar. Those who can afford it could have a small electric car for daily work commute, and a larger "long range (LR)" car for occasional long trips. However this means paying full rego and insurance for a car that sits in a garage most of the time. (thats another debate: I hate paying full rego for a car that only has driven <3000kms/yr in the last 5 yrs - at least I have been able to get substantial insurance discount, but its still grossly disproportionate to the distance driven) Alternatively, one could hire a LR car for holidays. If this scenario became a social norm, that would mean a probable peak demand for such LR cars during holiday times, and these cars sitting unused at other times - economically not an appealing proposition. Note that the above is predicated on a model of individual car ownership. If you do away with individual car ownership and say have a community owned model, other options become possible. For example: You can have daily used of a ESR (Electric Short Range) car, and when you are going on a holiday, you use a ESR car, drive it to a "station" - board a LR vehicle and travel to your far away destination and there gain access to another ESR car. Note you can do this now (rent a car), but its expensive, compared to using your individually owned car. You could already do this right now, even with a 400km range, if you could for example have "car swap stations" within 400 kms to each other spread around. By the way, I believe "John Wayne" did this ... ride his horse to a place and change to a new horse somewhere on the trip and continued his trip on another horse!!! Car share models do exist currently but tend to be localised and I dont think any satisfy the long distance scenario above(?). Car nowadays are generally designed and marketed for individual ownership. Even if they are fleet company cars, they are still designed to satisfy individual comfort preferences mostly. In contrast public transport vehicle are designed for the mass with lesser emphasis on individual preferences, obviously. If cars are to be build for sharing as standard practice, they would probably have to be designed differently, and have features to facilitate sharing. Here is another side to this. As we know them today, cars are actually incredibly inefficient means of transportation and possibly the least efficient peaceful use machine ever invented by man, in terms of energy use!!! The fact is 90%+ of the energy used by a car is wasted energy!!! Think about it: the average car weighs about 1200-1500kg. The average person say weighs between 70-90kgs.......it actually means that for every $1 spent on using a car today, 90c+ is actually spent moving an empty car!!! Why the hell would anyone sensibly want to drive an empty car around??? You could improve on this by loading a car with full passenger load and luggage, but you are still wasting a lot of energy!! Or you could build much lighter cars - but that does not appear to be coming soon, and lighter cars would have to be much much lighter! Thats where public transport becomes so much more energy efficient! In fact flying is more energy efficient than driving the average car on the road today. Riding a motorbike would be more efficient. We have used car for most of a century now, and they have been successful because the cost of using them was relatively low for those who could afford them in the first place - cheap energy/petrol. Btw, simply replacing petrol with electric propulsion and otherwise keep on designing car more or less as they are today, does nothing to improve the energy efficiency issue. We perhaps need to slowly get used to the demise of individual car ownership in the long term and re-invent what we expect and demand of them. When Ford, Holden and Toyota announced the closure of their manufacturing plant here, it nay well be the early sign of this inevitable change. We could start thinking about designing and manufacturing SPVs instead of SUVs: Sharable Personal Vehicles. So until "Scotty is ready to beam anyone of us to our holiday destination" we better also get used to using more of Public/Mass Transportion means or may be look forward to SPV's. Cheers, Daniel.