My inclination is to reject this notion out of hand, and I would were it not for the fact that I have considered doing just that for some time, and am presently considering an even lighter vehicle.
The whole idea strikes me as mega cool. So cool that we could name the electrical three wheeler the Apple! Needless to say there are some draw backs. The first is that the electrical three wheeler might not be safe, or at least safe enough, Can you imagine Ralph Nader writing an expose of the 650 pound car titled "Unsafe at any Voltage."
My concern rests on an analysis of a shopping trip in my spiffy three wheeler.
Now I drive to the nearest shopping center on Clinton Highway via Pleasant Ridge Road. a winding 40 MPH two lane artery, with less than great visibility.
Pleasant Ridge Road does not look safe for such a tiny, flimsy electric vehicle, does it? Not with cars that are more than five times more massive, not to mention the pick up trucks. So I face this quandary, I can get an electric three wheeler for under $2000. It is sort of cool, and will get me to the shopping center, where I usually shop. But I cannot convince myself that it is safe.
In addition I have other concerns. My wife and I travel in our area. Our latest trip was to Norris Dam. Making such trips are quality of life issues for my wife and myself. Norris Dam is not far from our home, but we would probably need a vehicle with a 50 miles range to be comfortable driving there. A hundred mile range might be needed if we wanted to spend the day in the Smokies. Greater range means more batteries and greater weight. Only the first vehicle on this page might be remotely practical for such trips. It is a hybrid, and has a cost of perhaps $18,000 to $23,000. You can buy a lot more car for that sort of money, although a lot a lot better gas millage will come with the three wheeler. Bigger all-electric cares are possible, but they will require bigger batteries, and bigger batteries cost money and add to auto weight.
Thus the argument for the 650 pound car breaks down once safety and transportation range requirements are considered. A 650 pound or even lighter car might be possible for in town shopping trips, but will consumers be comfortable with their safety characteristics?
The energy efficiency question can be looked at from another perspective, applying efficiency to the production of energy. My argument has always been that efficiency is the solution posed by most nuclear related problems. One reason for adopting Molten Salt nuclear technology, is its potential for efficient manufacture and efficient use. The Molten Salt Reactor is the reactor equivalent of the 650 pound car, but with out the safety hazards posed by Pleasant Ridge Road, and without the 650 pound car's trip distance limitations. In fact the Molten Salt Reactor can manufacture its own fuel, so potentially you can keep it running for periods of time up to 30 years.
I have pointed out several times on Nuclear Green that the factory manufacture process makes more efficient use of labor, and that the limitation of factory manufactured large reactor is that they have to be manufactured as kits, with final assembly taking place on site. By shifting to smaller reactors, the number of pieces in the kit can be limited, so on site assembly does not require a lot of labor or time.
The cores of Molten Salt Reactors can be very simple and easy to manufacture, Molten Salt Reactor parts need not be built form exotic and expensive materials. It may be possible to build Molten Salt Reactors from composite materials similar to the composite materials that go into aircraft. Even when comity type materials such as steel are used in MSR parts, MSRs can be designed to operate at higher temperatures than conventional reactors, and thus will produce electricity with greater thermal efficiency.
One of my Nuclear Green readers "Engineering" recently commented on an old Nuclear Green Post,
Writing in the wake of the Fukushima events, I find it striking that the report speaks of “safety” without distinguishing between radiation exposure hazards inside the plant and massive release of radioactive materials into the environment. Avoiding massive external release is (a) more important, (b) the greatest MSR safety advantage, and (c) an unmentionable advantage in the already-risk-free Milton Shaw world."Engineering" is arguing that in MSRs greater nuclear safety is consistent with more efficient, low cost nuclear technology. Now that is quite a trick, but it is part of the beauty of the Molten Salt Reactor concept.
In conclusion, it would appear that efficient 650 pound cars face a rocky road, with safety and range problems, but more efficient nuclear technology via the Molten Salt Reactor concept is possible, and is consistent with improved nuclear safety.