Friday, July 26, 2013

Electric velomobiles - the future of transportation?

I decided to continue the cars & bicycles theme, I started with my previous post and write a quick summary about an interesting article I found a few months ago. LowTechMagazine is a website dedicated to the technology that may make or made our life simpler, more efficient and less energy-dependent but without the unnecessary complexity of many modern solutions. Bicycles, as one of the most efficient transportation vehicles known to a man, obviously fit well in this category. But they are not perfect:

Few people find the bicycle useful for distances longer than 5 km (3 miles). In the USA, for instance, 85 % of bicycle trips involve a trip of less than 5 km. Even in the Netherlands, the most bicycle-friendly country in the western world, 77 % of bike trips are less than 5 km. Only 1 % of Dutch bicycle trips are more than 15 km (9 miles). In contrast, the average car trip amounts to 15.5 km in the USA and 16.5 km in the Netherlands, with the average trip to work being 19.5 km in the USA and 22 km in the Netherlands. (Sources: 1, 2, 3, 4, 5.) It's clear that the bicycle is not a viable alternative to the car. Depending on his or her fitness, a cyclist reaches cruising speeds of 10 to 25 km/h, which means that the average trip to work would take at least two to four hours, there and back.
 
According to the author, the solution may come in form of electric velomobiles but not electric cars (at least in their current form). It is because
While electric velomobiles have a speed and range that is comparable to that of electric cars, they are up to 80 times more efficient. If all 300 million Americans replace their car with an electric velomobile, they need only 25 % of the electricity produced by existing American wind turbines. (...) Now imagine that all 300 million Americans replaced their cars with an electric version like the Nissan Leaf, and all drive to work on the same day. To charge the 24 kW battery of each of those 300 million vehicles, we need 7,200 Gwh of electricity. This is 20 times more than what American wind turbines produce today.
This fantastic efficiency of electric velomobiles comes from the fact that

At speeds below 10 km/h (6 mph), rolling resistance is the biggest challenge for a cyclist. Air resistance becomes increasingly influential at higher speeds, and becomes the dominant force at speeds above 25 km/h (15.5 mph).

which means that once we keep moving in a velomobile, we can easily reach "average speed of 40 km/h (25 mph)". But since velomobiles are heavier than regular bicycles, bringing them up to that speed takes some extra energy. This is where electric assist comes handy. The assisted velomobile author tested had a suprisingly small battery on board, only used for acceleration, not cruising. But as calculation showed, "adding only 6 kg of batteries increases the range of the electric velomobile to 450 km". This is much, much better than any electric car that exists today. For example,

The Nissan Leaf takes you at best 160 km, when you drive slowly and steadily, and when you don't make use of the air-conditioning, heating or electronic gadgets on board.
This answers any questions on why electric cars still have such a pathetic range today, despite all progress in battery and electric motor technology. They are just too heavy and too complex. We are so used to our gasoline-powered cars that we don't want to give up on air conditioning, powered windows, heating system, radio and navigation. But all these things suck juice from batteries very quickly and decrease car's range. Velomobiles, thanks to their simplicity, don't have this problem. In fact,
when we compare the (electric velomobile) with the electric car, still viewed by many as the future of sustainable transportation, it's a clear winner.

Unfortunately, this kind of future doesn't look very bright. It is because

The biggest obstacle for manufacturers and drivers of electric velomobiles is legislation.
There are no unified regulations regarding the use of electric (and unassisted) velomobiles. In some countries, these vehicles are viewed as a bicycle and are required to travel on bike paths (even though they will not fit on many of them), in others, they are viewed as mopeds. Some countries allow velomobiles to use their electric motors at any speed, others, only up to 25km/h (15.5 mph). All these regulations (or the lack of them) lead to
the very strange fact that a car, for instance a Porsche Cayenne Turbo S with a weight of 2,355 kg, an engine of 382,000 watts and a top speed of 270 km/h can be driven anywhere on Earth, while an electric velomobile with a weight of 35 kg, a motor of 250 watts and an electric assistance of up to 50 km/h is illegal in most countries.

Can electric velomobiles be the future of mid-range transportation? The author seems to think so. And even if the rest of the article considers an utopian scenario of replacing all cars with velomobiles, it is an interesting read.

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