Low-tech Magazine

Get wired (again): Trolleybuses and Trolleytrucks

2009-07-10T01:18:09+02:00

A large-scale introduction of electric cars faces many technological hurdles and promises to be time-consuming and expensive.

Greening public transportation and cargo traffic, on the other hand, could be done fast with existing technology for a reasonable price - if we opt for the trolleybus and the trolleytruck.

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Obviously, the technology works, because otherwise it would not have been in service for such a long time in so many places.

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A trolleybus (or "trackless trolley") can be defined in two ways; as an electric bus that gets its power from overhead cables, or as a tram (or "street car") that drives on rubber tyres. Whichever way you look at it, this combination of bus and tram is the most ecological (motorised) means of transport that exists in the world today. Just like all other electrically powered vehicles (cars, trains, trams) a trolleybus does not produce exhaust fumes, is more efficient than vehicles with a combustion engine, and can drive on renewable energy. The trolleybus, however, has interesting advantages over other electric vehicles.

Cheap, fast, durable

A trolleybus does not need a battery. In this way, it bypasses the weak point of electric cars. Batteries limit the mileage of electric cars to a maximum of 200 to 300 miles, which means that the vehicles require an elaborate infrastructure for fast-charging or swapping batteries (see "Who killed the electric grid?"). Batteries also make electric vehicles heavy and thus less energy efficient than when hooked up to an overhead line - a battery makes up at least one third of the weight of an electric car.

A trolleybus also has advantages compared to other means of electric public transport. Contrary to a train or a tram, a trolleybus does not need a rail infrastructure. This not only results in huge cost and time savings, it also saves a large amount of energy (see for instance this paper: "Envirnmental assessment of passenger transportation should include infrastructure and supply chains", pdf). Installing a trolleybus service is of course more expensive than installing a normal bus line, but that extra cost can be recovered because of lower fuel and maintenance costs.

Furthermore, a trolleybus has better braking power than a tram and it is better at climbing hills, since rubber tyres have more grip than steel wheels on steel rails. Trolleybuses are also compatible with bicycles because cyclists cannot get stuck in the tracks. They are more manoeuvrable than trams - a badly parked car will not stop them, because they can diverge from their track for a couple of metres.

Political advantage

Being public transport, trolleybuses of course have the same advantages as trams; they use much less energy and space per passenger than cars. The trolleybus is not only cheap and ecologically sound, it is also fast to implement. There is no need to break up the road, no need to install a charging infrastructure; just attach overhead lines and off you go. This is a political advantage. The announcement and implementation of a system can happen in the same term of service. Because trolleybuses are cheaper than trams, they can also be used on trajectories where a tram would not find sufficient passengers to be cost-effective.

History and evolution

The first trolleybus got hooked up in 1882; the Elektromote, built by Ernst Werner von Siemens. However, it took almost 20 more years before the first commercial line was installed - in Bielatal, close to Dresden in Germany. During the first half of the twentieth century, and especially since the 1930s, the trolleybus was a success story. Around 1950, there were some 900 trolleybus systems operating worldwide. A large share of these was done away with in the 1960s and 1970s, mostly to the advantage of private cars and diesel buses.

Still, in many cities, the trolleybus never disappeared. Today 359 cities worldwide still operate trolleybus lines, the number of buses is estimated at 40,000. Most trolley services are located in the former Soviet Union and Eastern Bloc countries - probably another reason for their lousy image. The 1,300 kilometre network in Moscow is the largest in the world - it has 1,500 buses and 100 lines.

Minsk, the capital of Belarus, has the second largest network in the world with 1,050 buses and 68 lines. Saint Petersburg has the fourth largest network in the world with 735 buses spread across 41 lines (following Beijing, China, in third place). Ukraine has trolleybuses in more than 25 cities and it boasts the longest trolley line in the world: 85 kilometres from Yalta to Simferopol. The three largest networks in the European Union are Athens, Riga and Bucharest. Belgrade, Bratislava, Budapest, Kiev and Sofia are other former Eastern Bloc cities with large trolleybus networks.

Outside Europe

Switzerland has trolleybuses in 13 cities. Dozens of other cities in Europe have smaller networks. Outside Europe there are trolleybus systems in the US (Boston, Cambridge, Philadelphia, Dayton, San Francisco, Seattle), Canada (Vancouver, Edmonton), Central-America (Mexico City, the largest network in the Americas), Latin-America (Argentina, Brazil, Ecuador, Chile) and Asia (China, North-Korea). (sources: 1 / 2 / 3).

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The capital investment of the 19 kilometre line in Quito was less than 60 million dollar - hardly sufficient to build 4 kilometres of tram line, or about 1 kilometre of metro line.

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Obviously, the technology works, because otherwise it would not have been in service for such a long time in so many places. This cannot be said of electric cars, which all but disappeared in the 1920s.

Inferior technology

Compared to diesel buses, trolleybuses do have a couple of disadvantages. A trolleybus is more manoeuvrable than a tram, but less so than a diesel bus. If the road is being repaired or rebuilt in a street where trolleybuses pass, chances are that the line has to be discontinued temporarily. A diesel bus can easily be re-routed. Similar to trams, trolleybuses also cannot overtake each other.

The most important drawback of trolley systems is the need for overhead cables. They are generally regarded as ugly and meet protest. Especially at crossroads the cable network can be dense and hard to ignore. Similar to trams, the "tracks" of trolleybuses have points, but the whole mechanism of these hangs in the air. We adore wireless technology and that is probably the reason why trolleybuses are regarded as a ridiculous and inferior technology, a relic from the past.

Hybrid trolleybuses provide an answer to most of these disadvantages. By equipping trolleybuses with a battery or an auxiliary diesel motor, the bus can also cover a part of the route without depending on the overhead cables. Most trolleybuses built since 1990 are equipped with at least a small battery or diesel motor for some limited manoeuvring. This can save the installation of overhead cables, especially at turning points and in sheds, where normally a complicated infrastructure is needed to manoeuvre the buses. It can also help to get round road works.

On some lines (like in Boston and Philadelphia) hybrid trolley services exist. The bus then covers part of the route on electricity delivered by the overhead cables, while another part is covered by means of a (larger) battery or a diesel engine. In this way some drawbacks of batteries and diesel engines are introduced, but these disadvantages are limited when compared to electric cars or diesel buses. Hybrid buses might be a way to spare some parts of a city of overhead lines.

New trolleybus lines

Although some cities have recently decided to stop their (modest) trolley services (Ghent in Belgium, Innsbruck in Austria, Marseille in France and Edmonton in Canada), there are many more cities that have recently expanded or modernised their network, re-introduced trolleybuses, or introduced them for the first time.

In France, the trolley lines in Limoges, Saint-Étienne and Lyon (the largest network in France) have recently been expanded and renewed. One line in Nancy (abolished in 1998) will be restored in 2010. In Athens the full fleet of 350 vehicles has been renewed. In Italy trolleybuses have been re-introduced in Rome in 2005 (only one line) and new systems are coming in Lecce, Avellino en Pescara. The system in Bari will be re-opened. A dozen other Italian cities have never abolished their trolley services and do not have any intention of doing so.

Castellón de la Plana, a city in Spain, re-introduced trolleybuses in 2007, the service was expanded in 2008. In Salzburg (the largest network in Austria with 80 buses and 7 routes) the service was recently expanded. A new system is planned in Leeds in the United Kingdom, which would be the first re-introduction of trolleybuses in the UK in 30 years. Vancouver in Canada renewed its buses in 2007 and 2008, Wellington in New Zealand did the same. Even Ethiopia announced a trolleybus system in 2008.

El Trole

The most spectacular progress is made in South-America. This has everything to do with "El Trole", the trolleybus network in Quito (below), the capital of Ecuador with 1.6 million inhabitants. The already impressive network, built in 1995, was expanded in 2000 and 2008. On a part of the main line (with a length of 19 kilometres) the trolleybuses make use of exclusive lanes, completely separated from other traffic.

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If we want to, we can do the switchover in just a few years time.

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During peak hours, there is a bus every 50 to 90 seconds (because of the high frequency, there are no schedules). El Trole transports 262,000 passengers each day. Five other trolleybus lines connect to it, as well as several other bus lines (including Ecovía, a line similar to El Trole but using diesel buses). The average distance between stops is 400 metres.

The system in Quito is being copied in Mérida (Venezuela), the first part of that line opened in 2007 (picture below). Other cities in Latin America study the possibility of installing a similar infrastructure, and the Quito system was also the inspiration for the proposals in England and Scotland (second and third picture below).

By choosing the cheaper trolleybus over tram or metro, Quito could develop a much larger network in a shorter time. The capital investment of the 19 kilometre line was less than 60 million dollar - hardly sufficient to build 4 kilometres of tram line (source), or about 1 kilometre of metro line (source). Lower investment costs also mean lower ticket fares, and thus more passengers.

Furthermore, the system is well devised (pdf). There is only one ticket fare, payment happens in the station, not on the bus. Stops are comfortable and built to get fast in and out of the bus, there are very good connections with other lines (sometimes via the same stop), and thanks to the exclusive lanes and (at some crossroads) automatically controlled traffic lights the system is extremely reliable. In Quito, the bus always arrives on time.

Unfortunately, El Trole has become a victim of its own success. The Ecuadorian government now plans to convert (the larger part of) the main line to a much more expensive light rail line (TRAQ, pdf, in Spanish), arguing that the network is saturated. A protest group consisting of citizens and traffic engineers ("Quito para todos") opposes the 500 - 750 million dollar plan and demands that the money is used to extend of the trolleyline instead:

"The same investment required to build the 20 to 30 km of light rail would build 250 km of exclusive lanes for trolleybuses including vehicles, stations and terminals. Quito's system of rapid urban mass transport would be complete, providing efficient service, with money left over for construction of bikeways throughout the city, for recovery and integration of public spaces, widening of sidewalks, planting trees and providing urban furniture, building walkways between bus stops and passenger destinations, and other projects to complement the system, in such a way to be able to have a city with an optimal public transport service, placing us in the lead among cities with the best public transport in the world."

Whatever the outcome in Quito will be, the many advantages of a trolleybus line should not lead to the conclusion that light rail systems are evil or unnecessary. When passenger capacity grows, it can make sense to convert the busiest trolleylines to light rail systems. The income of a popular trolleyline might serve to finance the succeeding rail network. Another compromise: rail-guided trolleys. These vehicles have rubber tyres but are guided by one rail in the middle, which makes it possible to use longer vehicles.

Trolleytrucks

Trolley systems can also be used for the transport of goods. "Trolleytrucks" are a lesser known technology but have an equally long history. Initially, they were as popular as trolleybuses, transporting goods between factories and train stations. Especially the German engineer Max Schiemann put together some remarkable examples in the beginning of the 20th century.

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There are more elegant options than trolleytrucks, like underground freight networks. Cost, however, is a serious obstacle.

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The technology never really took off, though. Trolleytrucks are still sporadically used in Russia and Ukraine (pictures), and in the mining industry (below, more pictures). However, in the latter case, the electric engine does not replace the diesel engine, but merely assists it.

Another historical example is the "Valtellina Dam Project" in Italy (below). These two lines with a total length of 80 kilometres were built in 1936 and remained in service until 1962. Twenty trolleytrucks transported concrete, sand and other construction materials to build two large dams.

Today there are no cities that plan a trolleytruck system, but the German city of Dresden does have a Cargo Tram (see below, it is also being tested in Amsterdam). From there it is only one step to a trolleytruck service, as imagined by this inventor.

Trolleytrucks and trolleybuses are also put forward as a solution in the 2008 book "Transport Revolutions: moving people and freight without oil". Authors Richard Gilbert and Anthony Perl propose a plan that would include 500 billion tonne-kilometres of cargo moved by "trolleylorry" in the US by 2025. Trolleytrucks would replace trucks, and complement cargo trains.

High-tech alternatives to trolley systems

There are more elegant options than trolleytrucks, with the same advantages, like the underground freight networks we discussed before. Cost, however, is a serious obstacle. Another alternative for both trolleybuses and trolleytrucks are (wireless) electric buses and trucks, but they too will always be much more expensive, and also less efficient than trolleys - then we are talking about batteries again.

If a bus or truck has a mileage of 100 kilometres, and you have to drive 120 kilometres, you are in trouble. This problem can be solved in two ways. You can put more batteries in your vehicle, but then you increase the cost and the weight and you lower the cargo or passenger space.

Or you can set up fast-charging stations or battery swapping stations along the way, but then you increase the costs even more. It gets worse when you start thinking of wirelessly charged buses and trucks. This is a technology that no doubt appeals to more people than trolleybuses do, but it will always be less efficient and more expensive.

All too often we are blind for the costs of high-tech. If we cannot afford a technology, it is of not much use. Low-tech options that have been proven to work can deliver much better results for a bargain. The technology to completely electrify land based transportation has been available for over a hundred years. If we want to, we can do the switchover in just a few years time. Let's start with public transport and cargo traffic, and then let's see what to do with cars - if we still need them.

Trolleycars, even though theoretically possible, are not a practical option.

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A world without trucks : underground freight networks
Why the electric car has no (wireless) future
Who killed the electric grid? fast-charging electric cars
The age of speed : low-tech energy efficiency
Sailing at the touch of a button : wind-powered, computer-controlled
Early trolleytruck convoys in Germany
Planes on wheels : high speed trains
Leave the algae alone : biofuels
Low-tech cars
Only idiots travel by train

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Electric road trains in Germany, 1901 - 1950

2009-07-09T16:01:28+02:00

German engineer Max Schiemann was among the first engineers to develop a commercial trolleybus system for passengers at the turn of the 20th century. He also created some unique cargo systems.

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1. Hafenschleppbahn in Altona (1912-1950)

The most succesfull (and most remarkable) trolleytruck network designed and constructed by Schiemann was the "Hafenschleppbahn" in Altona, today an area in Hamburg. The road from the port to the town was so steep that horses had severe difficulty climbing it. Trolleytruck technology came to the rescue, but the electric trucks on the one kilometre long track (up and down) did not replace the horses.

The trucks were used as an assisting power source. As can be seen on the pictures below, the trolleytruck pushed or pulled one or more horse cars, while other wagons (handcarts included) were also attached to the convoy. (The guy on the bike is not).

This hybrid system combining electricity with animal and human power started operation in 1912 and remained in service until 1950. Each day, around 200 wagons were pulled or pushed up the hill, each convoy transporting 5 to 7 tonnes of cargo. In the first ten months of its existence, the road trains took more than 22,000 wagons up the hill. Total electricity consumption during that period was 30,878 kilowatt-hours.

The maximum speed of the trolleytrucks was 10 kilometres per hour while climbing the hill and 30 kilometres per hour on flat terrain. The average speed of the convoy was 5 to 8 kilometres per hour and the trip up the hill took 8 minutes, coupling and uncoupling included. In total six trucks were used, several of them at the same time (two trucks crossing posed no problem since the one coming down was not connected to the overhead line).

Fees were collected during the trip. The service was initially exploited by the "Gesellschaft für gleislose Bahnen Max Schiemann & Co.", from 1922 it was run by the town of Altona, and later by the city of Hamburg.

2. Bielatal Bahn (1901-1904) & Industriebahn Wurzen (1905-1928)

The first system built by Schiemann and his "Geselschaft für gleislose Bahnen Max Schiemann & Co." was the "Bielatalbahn", a 2.8 kilometre long track in Sachsen. It carried both passengers and cargo (mainly for a paper factory). The track operated only from 1901 to 1904, but the infrastructure was reused to build (part of) a new line close to Leipzig: the "Industriebahn Wurzen", an exclusive cargo line which was in operation from 1905 until 1928.

It was 3.46 kilometres long (4.23 kilometres up to 1914, when an extra track was in use). The cargo system consisted of 2 trolleytrucks, 10 wagons for coal transport (each with a capacity of 6 tons) and 27 wagons for flour transport (each with a capacity of 5 tons). Each truck had a power output of 25 HP and could pull a maximum of 3 wagons with a total weight of 15 tonnes (comparable to this contemporary truck).

The speed of the road train was 6 kilometres per hour when loaded and 8 kilometres per hour when unloaded. The trolleytrucks were initially equipped with wood and iron wheels with spokes, only later to be replaced by rubber tyres. The same trucks were used for the full 23 years, accidents did not occur.

The line was constructed to transport flour from a flour mill to the cargo train station. An extra track carried coal from a mine to the station, but was closed when the mine shut down in 1914. On average, 300 tons of cargo was transported each day. Planned extensions to a wallpaper factory and a felt factory were never realised.

Since the production facilities of Schiemann were located in the same town, the track was also used to test vehicles and convoys for other lines. Allegedly, the owner of the flour mill also had a small private passenger vehicle for use on the line.

3. Kalkbahn Grevenbrücker (1903-1907)

The first trolleyline built exclusively for cargo (the "Kalkbahn") was installed in Grevenbrück, a village in the present-day municipality of Lennestadt in Nordrhein-Westfalen. The 1.5 kilometre trajectory served to transport limestone from a quarry (opened in 1902) to the train station. The route went straight through the town and crossed an old bridge. The line opened in 1903 and was closed in 1907, when the quarry was relocated. The service was operated by the mining company itself, the "Grevenbrücker Kalkwerke".

About 20 convoys passed each day, at a speed of 6 kilometres per hour (loaded) or 7 to 8 kilometres an hour (unloaded). The trucks could pull 3 to 4 wagons (each with a capacity of 5 to 6 tonnes) in good weather conditions, and 2 wagons when there was ice or snow.

In winter, the trolleytrucks were equipped with snow tyres (above). For the same reason, the wagons on the first Schiemann system (the Bielatalbahn described above) were equipped with skates.

The trolleytruck was also used to pull a rolling mill for road building (below). The "Kalkbahn" was built in just 3 months. Financial savings were about 33 percent compared to the same trajectory by horse cart.

The town of Grevenbüch also had a second line, the "Veischedetal Bahn" (scroll down), which was in operation from 1904 to 1916. Until 1907 it transported both passengers and goods (mainly tobacco to some cigar factories), after that date it carried only passengers and mail. The route was 8 kilometres long and the vehicles attained a speed of 18 km/h. Both trolley lines came together at the train station, but they were not interconnected.

4. Other Schiemann trolley lines

Max Schieman built 12 lines in total: several passenger trolley lines as well as some more routes that were used to transport both passengers and cargo. The "Gleislose Bahn Blankenese-Marienhöhe" (below) had a length of 3 kilometres and carried passengers between the train station and the town. It was in operation from 1911 to 1915. The passenger line "Gleislose Bahn Ahrweiler" was in operation from 1906 to 1917 and had a length of 5.5 kilometres.

The 4.5 kilometres long "Gleislose Bahn Monheim-Langenfeld" transported both goods (5,000 tonnes per year), passengers and mail. It was in operation from 1904 to 1908 and was the only line that was discontinued because of technical problems - the trucks were too heavy and damaged the road.

Contemporaries of Schiemann, building or experimenting with trolleytruck systems, were Werner von Siemens, Lombard Und Guérin (France), Carl Stoll, Charles Nithard (France), E.Cantono (Italy), Hans-Ludwig Stoll and Lloyd-Köhler. World War I slowed down the further development of trolley systems, and it was only in the 1930s that the technology really took off. Only for passengers, though, since cargo systems never became widespread.

Trolleytrucks (and trolleybuses) would make a lot of sense these days.

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Related

Trolleybuses and trolleytrucks : electric transport for a bargain

A world without trucks : underground freight networks

Only idiots travel by train : how can you blame people for flying if there is no affordable alternative?

Life before television : 17th, 18th and 19th century optical entertainment

A steam powered submarine : the Ictíneo

Moonlight towers : the arc lamp

Cargo ships, then and now : which one is fastest ?

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The monster footprint of digital technology

2009-06-16T16:53:00+02:00

The power consumption of our high-tech machines and devices is hugely underestimated.

When we talk about energy consumption, all attention goes to the electricity use of a device or a machine while in operation. A 30 watt laptop is considered more energy efficient than a 300 watt refrigerator. This may sound logical, but this kind of comparisons does not make much sense if you don't also consider the energy that was required to manufacture the devices you compare. This is especially true for high-tech products, which are produced by means of extremely material- and energy-intensive manufacturing processes. How much energy do our high-tech gadgets really consume?

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Artwork: cityscape I & II by Grace Grothaus.
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The energy consumption of electronic devices is skyrocketing, as was recently reported by the International Energy Association ("Gadgets and gigawatts"). According to the research paper, the electricity consumption of computers, cell phones, flat screen TV's, iPods and other gadgets will double by 2022 and triple by 2030. This comes down to the need for an additional 280 gigawatts of power generation capacity. An earlier report from the British Energy Saving Trust (The ampere strikes back - pdf) came to similar conclusions.

There are multiple reasons for the growing energy consumption of electronic equipment; more and more people can buy gadgets, more and more gadgets appear, and existing gadgets use more and more energy (in spite of more energy efficient technology - the energy efficiency paradox described here before).

The 180 watt laptop

While these reports are in themselves reason for concern, they hugely underestimate the energy use of electronic equipment. To start with, electricity consumption does not equal energy consumption. In the US, utility stations have an average efficiency of about 35 percent. If a laptop is said to consume 60 watt-hours of electricity, it consumes almost three times as much energy (around 180 watt-hour, or 648 kilojoules).

So, let's start by multiplying all figures by 3 and we get a more realistic image of the energy consumption of our electronic equipment. Another thing that is too easily forgotten, is the energy use of the infrastructure that supports many technologies; most notably the mobile phone network and the internet (which consists of server farms, routers, switches, optical equipment and the like).

Embodied energy

Most important, however, is the energy required to manufacture all this electronic equipment (both network and, especially, consumer appliances). The energy used to produce electronic gadgets is considerably higher than the energy used during their operation. For most of the 20th century, this was different; manufacturing methods were not so energy-intensive.

An old-fashioned car uses many times more energy during its lifetime (burning gasoline) than during its manufacture. The same goes for a refrigerator or the typical incandescent light bulb: the energy required to manufacture the product pales into insignificance when compared to the energy used during its operation.

Advanced digital technology has turned this relationship upside down. A handful of microchips can have as much embodied energy as a car. And since digital technology has brought about a plethora of new products, and has also infiltrated almost all existing products, this change has vast consequences. Present-day cars and since long existing analogue devices are now full of microprocessors. Semiconductors (which form the energy-intensive basis of microchips) have also found their applications in ecotech products like solar panels and LEDs.

Where are the figures?

While it is fairly easy to obtain figures regarding the energy consumption of electronic devices during the use phase (you can even measure it yourself using a power meter), it is surprisingly hard to obtain reliable and up-to-date figures on the energy consumed during the production phase. Especially when it concerns fast-evolving technologies. A life cycle analysis of high-tech products is extremely complex and can take many years, due to the large amount of parts, materials and processing techniques involved. In the meantime, products and processing technologies keep evolving, with the result that most life cycle analyses are simply outdated when they are published.

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The embodied energy of the memory chip alone already exceeds the energy consumption of a laptop during its life expectancy of 3 years

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For more recent and emerging technologies, life cycle analyses simply do not exist. Try looking for a research paper that calculates the embodied energy of a Light Emitting Diode (LED), a lithium-ion battery or any device full of electronics meant to save energy: you won't find it (and if you do, please let me know).

Embodied energy of a computer

The most up-to-date life cycle analysis of a computer dates from 2004 and concerns a machine from 1990. It concluded that while the ratio of fossil fuel use to product weight is 2 to 1 for most manufactured products (you need 2 kilograms of fuel for 1 kilogram of product), the ratio is 12 to 1 for a computer (you need 12 kilograms of fuel for 1 kilogram of computer). Considering an average life expectancy of 3 years, this means that the total energy use of a computer is dominated by production (83% or 7,329 megajoule) as opposed to operation (17%). Similar figures were obtained for mobile phones.

While the 1990 computer was a desktop machine with a CRT-monitor, many of today's computers are laptops with an LCD-screen. At first sight, this seems to indicate that the embodied energy of today's machines is lower than that of the 1990 machine, because much less material (plastics, metals, glass) is needed. But it is not the plastic, the metal and the glass that makes computers so energy-instensive to produce. It's the tiny microchips, and present-day computers have more of them, not less.

100 years of manufacturing

The energy needed to manufacture microchips is disproportional to their size. MIT-researcher Timothy Gutowski compared the material and energy intensity of conventional manufacturing techniques with those used in semiconductor and in nanomaterial production (a technology that is being developed for use in all kinds of products including electronics, solar panels, batteries and LEDs).

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Digital technology is a product of cheap energy

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As an example of more conventional manufacturing methods, Gutowski calculated the energy requirements of machining, injection molding and casting. All these techniques are still used intensively today, but they were developed almost 100 years ago. Injection molding is used for the manufacture of plastic components, casting is used for the manufacture of metal components, and machining is a material removing process that involves the cutting of metals (used both for creating and finishing products).

6 orders of magnitude

While there are significant differences between configurations, all these manufacturing methods require between 1 and 10 megajoule of electricity per kilogram of material. This corresponds to 278 to 2,780 watt-hour of electricity per kilogram of material. Manufacturing a one kilogram plastic or metal part thus requires as much electricity as operating a flat screen television for 1 to 10 hours (if we assume that the part only undergoes one manufacturing operation).

The energy requirements of semiconductor and nanomaterial manufacturing techniques are much higher than that: up to 6 orders of magnitude (that's 10 raised to the 6th power) above those of conventional manufacturing processes (see figure below, source, supporting information). This comes down to between 1,000 and 100,000 megajoules per kilogram of material, compared to 1 to 10 megajoules for conventional manufacturing techniques.

Manufacturing one kilogram of electronics or nanomaterials thus requires between 280 kilowatt-hours and 28 megawatt-hours of electricity; enough to power a flat screen television continuously for 41 days to 114 years. These data do not include facility air handling and environmental conditioning, which for semiconductors can be substantial.

Embodied energy of a microchip

The energy consumption of semiconductor manufacturing techniques corresponds with a life cycle analysis of a "typical" 2 gram microchip performed in 2002. Again, this concerns a 32 MB RAM memory chip - not really cutting edge technology today. But the results are nevertheless significant: to produce the 2 gram microchip, 1.6 kilograms of fuel were needed. That means you need 800 kilograms of fuel to produce one kilogram of microchips, compared to 12 kilograms of fuel to produce one kilogram of computer.

If we take the energy density of crude oil (45 MJ/kg), this comes down to 72 megajoules (or 20,000 watt-hour) to produce a 2 gram microchip. Converted to a one kilogram microchip this comes down to 3.3 megawatt-hours of electricity (or 36,000 MJ), well within the range of the 280 kilowatt-hours (1,000MJ) and 28 megawatt-hours (100,000 MJ) calculated above.

Also, the International Technology Roadmap for Semiconductors 2007 edition gives a figure of 1.9 kilowatt-hours per square centimetre of microchip, so 20 kilowatt-hours per 2 gram, square centimetre computerchip seems to be a reasonable estimate.

How many microchips in a computer?

A gadget or a computer does not contain one kilogram of semiconductors - far from that. But, we don't need a kilogram of microchips to ensure that the manufacturing phase will largely outweigh the usage phase. The embodied energy of the memory chip alone already exceeds the energy consumption of the laptop during its life expectancy of 3 years.

Today's personal computers have a RAM-memory of 0.5 to 2 gigabyte modules that typically consist of 18 to 36 two-gram-microchips (as the ones described above). This equates to 1,296 to 2,595 megajoules of embodied energy for the computer memory alone, or 360,000 to 720,000 watt-hour. Enough to power a 30 watt laptop non-stop for 500 to 1,000 days.

Microprocessors (the "brains" of all digital devices) are more advanced than memory chips and thus contain at least as much embodied energy. Unfortunately, no life cycle analysis of a microprocessor has been published. Certain is that modern computers contain ever more of them.

One trend in recent years is the introduction of "multicore processors" and "multi-CPU systems". Personal computers can now contain 2, 3 or 4 microprocessors. Servers, game consoles and embedded systems can have many more. Each of these "cores" is capable of handling its own task independently of the others. This makes it possible to run several CPU-intensive processes (like running a virus scan, searching folders or burning a DVD) all at the same time, without a hitch. But with every extra chip (or chip surface) comes more embodied energy.

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The energy savings realised by digital technology will merely absorb its own growing footprint.

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Another trend is the rise of the "Graphics Processing Unit" or GPU. This is a specialised processor that offloads 3D graphics rendering from the microprocessor. The GPU is indispensable to play modern videogames, but it is also needed because of the ever higher graphical requirements of operating systems. GPU's do not only raise the energy consumption of a computer while in use (GPU's can consume more energy than current CPU's), but they also stand for more embodied energy. A GPU is very memory-intensive and thus also increases the need for more RAM-chips.

Nanomaterials

Why are microchips so energy-intensive to manufacture? One of the reasons becomes clear when you literally zoom in on the technology. A microchip is small, but the amount of detail is fabulous. A microprocessor the size of a fingernail can now contain up to two billion transistors - each transistor less than 0.00007 millimetres wide. Magnify this circuit and it becomes a structure as complex as a sprawling metropolitan city.

The amount of materials embedded in the product might be small, but it takes a lot of processing (and thus machine energy use) to lay down a complex and detailed circuit like that. While the electricity requirements of machines used for semiconductor manufacturing are similar to those used for older processes like injection molding, the difference lies in the process rate: an injection molding machine can process up to 100 kilograms of material per hour, while semiconductor manufacturing machines only process materials in the order of grams or milligrams.

Another reason why digital technology is so energy-intensive to manufacture is the need for extremely effective air filters and air circulation systems (which is not included in the figures above). When you build infinitesimal structures like that, a speck of dust would destroy the circuit. For the same reason, the manufacture of microchips requires the purest silicon (Electronic Grade Silicon or EGS, provided by the energy-intensive CVD-process).

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The manufacture of nanotubes is as energy-intensive as the manufacture of microchips.

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Every 18 months the amount of transistors on a microchip doubles (Moore's law). On one hand, this means that less silicon is needed for a certain amount of processing power or memory. On the other hand, when transistors become smaller, you need even more effective air filtration and purer silicon. Since the structure also becomes more complex, you need more processing steps.

Nanotechnology operates on an even smaller scale than micro-electronics, but its energy requirements are comparable. Carbon nanofiber production, which is based on many of the same techniques used by semiconductor manufacturing, requires 760 to 3,000 MJ of electricity per kilogram of material, while carbon nanotubes and single-walled nanotubes (SWNTs) manufacturing requires a hefty 20,000 to 50,000 MJ per kilogram. The manufacture of nanotubes is thus as energy-intensive as the manufacture of microchips (36,000 MJ). Many of the large-scale applications proposed for nanotubes will simply not be possible because of energy requirements.

Recycling is no solution

Encouraging recycling is often proposed as a way to lower the embodied energy of products. Unfortunately, this does not work for micro-electronics (or nanomaterials). In the case of conventional manufacturing methods, the energy requirements of the manufacturing process (1 to 10 MJ per kilogram) are small compared to the energy required to produce the materials themselves.

For instance, producing 1 kilogram of plastic out of crude oil requires 62 to 108 MJ of energy, while a typical mix of virgin and recycled aluminum requires 219 MJ. To make a fair comparison, you have to multiply the energy requirement of the manufacturing process by three (1 megajoule of electricity requires 3 megajoules of energy) but even then (with 3 to 30 MJ/kg) conventional manufacturing processes appear to be quite benign compared to materials extraction and primary processing (in the order of 100 MJ/kg - see table).

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Recycling is not a solution if all your energy use is concentrated in the manufacturing process itself.

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In the case of semiconductor manufacturing, this relation is reversed. While it takes 230 to 235 MJ of energy to produce 1 kilogram of silicon (already quite high compared to many other materials), chemical vapour deposition (an important step in the semiconductor manufacturing process) requires about 1,000 MJ of electricity and thus 3,000 MJ of energy per kilogram.

That is 10 times more than the energy consumption of material extraction and primary processing. In the case of conventional manufacturing techniques, the use of recycled material is an effective way to lower overall energy use during manufacture. In the case of semiconductors, it is not. Recycling is not a solution for energy consumption if all your energy use is concentrated in the process itself.

This does not mean that the manufacture of microchips does not require materials. In fact, producing microchips and nanomaterials is also more material intensive than the manufacture of conventional products, by the same orders of magnitude. However, this concerns auxiliary materials which are not incorporated into the product.

For example, the embodied energy of the input cleaning gases in the CVD process (not included in the figures above) is more than 4 orders of magnitude greater than that of the product output. Furthermore, these gases have to be treated to reduce their reactivity and possible attendant pollution. Gutowski writes: "If this is done using point of use combustion with methane, the embodied energy of the methane alone can exceed the electricity input."

The benefits of digital technology

Microchips also have positive effects on the environment, by making other activities and processes more efficient. This is the subject of a publication by the Climate Group, an initiative of more than 50 of the world's largest companies. The report ("Smart 2020 - enabling the low carbon economy in the information age") confirms the findings of other studies regarding the electricity use of electronic equipment, but also calculates the benefits.

According to Smart 2020, the emissions from Information and Communications Technology (including the energy use of data centres, which the IEA report does not include) will rise from 0.5 Gt CO2-equivalents in 2002 to 1.4 GtCO2-equivalents in 2020, assuming that the sector will continue to make the "impressive advances in energy efficiency that it has done previously". By enabling energy efficiencies in other sectors, however, ICT could deliver carbon savings 5 times larger: 7.8 Gt CO2-equivalents in 2020.

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Addressing technological obsolescence would be the most powerful approach to lower the ecological footprint of digital technology

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These benefits are smart grids (2.03 Gt), smart buildings (1.86 Gt), smart motor systems (970 Mt), dematerialisation and substitution (by replacing high carbon physical products and activities such as books and meetings - with virtual low carbon equivalents such as electronic commerce, electronic government, videoconferencing, 500 Mt) and smart logistics (225 Mt). One of the first tasks of ICT will be to monitor energy consumption and emissions across the economy in real time, providing the data needed to optimise for energy efficiency.

The report concludes: "The scale of emission reductions that could be enabled by the smart integration of ICT into new ways of operating living, working, learning and travelling, makes the sector a key player in the fight against climate change, despite its own growing footprint."

But even if we assume that all these savings will materialise (the report acknowledges that this will not be an easy task), this conclusion does not take into account the energy needed to manufacture all this equipment. If we assume the share of manufacture to be 80 percent of total energy consumption by ICT (following the only life cycle of a computer we have), then the 1.4 Gt in 2020 in reality should be 7 Gt - almost as much as the 7.8 Gt that will be saved by ICT. No environmental benefit would appear and the energy savings realised by digital technology would merely absorb its own growing footprint.

Digital technology is a product of cheap energy

The research of Timothy Gutowski shows that the historical trend is toward more and more energy intensive processes. At the same time, energy resources are declining.

Gutowski writes:

"This phenomenon has been enabled by stable and declining material and energy prices over this period. The seemingly extravagant use of materials and energy resources by many newer manufacturing processes is alarming and needs to be addressed alongside claims of improved sustainability from products manufactured by these means."

Production techniques for semiconductors and nanomaterials can and will become more efficient, by lowering the energy requirements of the equipment or by raising the operating process rate. For instance, the "International Technology Roadmap for Semiconductors" (ITRS), an initiative of the largest chip manufacturers worldwide, aims to lower energy consumption (pdf) per square centimetre of microchip from 1.9 kWh today to 1.6 kWh in 2012, 1.35 kWh in 2015, 1.20 kWh in 2018 and 1.10 kWh in 2022.

But as these figures show, improving efficiency has its limits. The gains will become smaller over time, and improving efficiency alone will never bridge the gap with conventional manufacturing techniques. Power-hungry production methods are inherent to digital technology as we know it.

The ITRS-report warns that:

"Limitations on sources of energy could potentially limit the industry's ability to expand existing facilities or build new ones".

Gutowski writes:

"It should be pointed out that there is also a need for completely rethinking each of these processes and exploring alternative, and probably non-vapour-phase processes".

Technological obsolescence

The ecological footprint of digital technology described above is far from complete. This article focuses exclusively on energy use and does not take into account the toxicity of manufacturing processes and the use of water resources, both of which are also several orders of magnitude higher in the case of both semiconductors and nanomaterials. To give an idea: most water used in semiconductor manufacturing is ultrapure water (UPW), which requires large additional quantities of chemicals. For many of these issues, the industry recognizes that there are no solutions (see the same ITRS-report, pdf). There are also the problems of waste & war.

Last, but not least: the energy-intensive nature of digital technology is not due only to energy-intensive manufacturing processes. Equally as important is the extremely short lifecycle of most gadgets. If digital products would last a lifetime (or at least a decade), embodied energy would not be such an issue. Most computers and other electronic devices are replaced only after a couple of years, while they are still perfectly workable devices. Addressing technological obsolescence would be the most powerful approach to lower the ecological footprint of digital technology.

Comments (9).

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The right to 35 mobiles

Carrier pigeon beats internet

Mechanical calculators: computing without electricity

The digital oubliette

Where is the second hand market for downloads?

Email in the 18th century

Solar panels mounted on gadgets are insane

Gaming unplugged

Low-tech solutions / Obsolete technology / Ecotech myths / Mixed links & updates at No Tech Magazine

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Fighting marine debris: the dustcarts of the sea

2009-06-13T16:41:27+02:00

Considering that the oceans hold more garbage than fish by now, this might be the right time to retrain our fishermen and let them hunt for litter. Several companies offer equipment to fish garbage out of rivers, lakes and harbours. They say they could build larger dustcarts for seas and oceans, too. Send the bill to the disposables industry - and let the cleanup begin.

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The British company Water Witch offers two boats that are especially designed to clean up marine debris. The Buddy Catamaran (above and below) is a litter retrieval and waterway maintenance boat for marinas, harbours and inland waterways.

Built from aluminium and designed for ease of operation and low cost of ownership, this road-transportable vessel features a removable basket, which can be lifted and tipped directly into a skip or shore side receptacle for disposal. The boat can filter a water surface of 92 x 92 metres per hour. The filter system can be adjusted to collect different sizes of flotsam.

The Water Witch workboat (below) could be compared to a floating bulldozer and features a powerful front end loader which can lift up to 1000 kg and reach to 3.65m below the waterline. About 100 of them are in use worldwide. A quick-release system ensures a range of loader attachments can be easily fitted in seconds. Attachments available include dredge buckets, log grapples, weed cutters/rippers, access platforms, cranes and more.

Modular skip barges allow recovered debris and waste to be stored and transported using transfer skips employed by waste removal contractors worldwide. Each barge features quick-connect couplings to allow additional units to be connected to suit capacity requirements.

Jackie Caddick, director of Water Witch, recently said in an interview that they could easily build much larger versions of their dustcarts if the money is available (source, in Dutch). Much larger garbage barges already exist (more here) :

The BBC points to 2 large skimmer boats (Thames Clearwater I & II, below) in the river Thames, custom built by Damen Shipyards in the Netherlands and launched in September 2007. The catamarans (24 metres long and 8.20 metres wide) are outfitted with the screening technology currently employed in land-based facilities.

The screens, located near midships, are designed to pick up small debris which is then deposited into storage containers located on deck. Larger debris is captured at the bow in coarse mesh buckets, which also allows the smaller items to pass through and move towards the finer debris screens that are found midships.

Spanish company Marnett offers totally different floating dustcarts, like the one below :

In the US, skimmer boats have been in use since the early 1980s. United Marine International manufactures the TrashCat, which comes in 3 sizes (pictures below). About 100 of them are in use worldwide. They are capable of collecting up to 1200 cubic feet (34 cubic meters) of floating debris per load. US company Alpha Boats sells similar machines.

Maybe we don't even need new boats. Fishing boats are very good at (unintentionally) catching marine debris. Fishing for litter is a North Sea project that encourages fishermen to collect garbage they find in their fishing nets. The cooperation of the vessels and their crew is without financial compensation, but recently a Belgian minister decided to pay fishermen 10 euro per garbage bag they bring on shore.

KDD

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Cargo ships, then and now : which one is fastest?

Ocean liners : from London to New York in 3 days and 12 hours.

The Kalakala : the art of slow travel.

The Ictíneo : a steam powered submarine.

The Aeromodeller II : the zeppelin that never lands.

The Hennepin Crawler : macho pedal power.

Trolleytrucks and trolleybuses : electric transport for a bargain

Sailrockets & kiteboats.

Low-tech solutions / Obsolete technology / Ecotech myths / Mixed links & updates at No Tech Magazine

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Small windmills put to the test

2009-04-19T21:15:49+02:00

A real-world test performed by the Dutch province of Zeeland (a very windy place) confirms our earlier analysis that small windmills are a fundamentally flawed technology (test results here, pdf in Dutch). Twelve of these much hyped machines were placed in a row on an open plain (picture above). Their energy yield was measured over a period of one year (April 1, 2008 - March 31, 2009), the average wind velocity during these 12 months was 3.8 meters per second (note: update on the wind speed). Three windmills broke. Find the disappointing results of the others below.

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Wind power rules, but small windmills are a swindle

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- Energy Ball v100 (4,304 euro) : 73 kWh per year, corresponding to an average output of 8.3 watts
- Ampair 600 (8,925 euro) : 245 kWh per year or an average output of 28 watts
- Turby (21,350 euro) : 247 kWh per year or an average output of 28.1 watts
- Airdolphin (17,548 euro) : 393 kWh per year or an average output of 44.8 watts
- WRE 030 (29,512 euro) : 404 kWh per year or an average output of 46 watts
- WRE 060 (37,187 euro) : 485 kWh per year or an average output of 55.4 watts
- Passaat (9,239 euro) : 578 kWh per year or an average output of 66 watts
- Skystream (10,742 euro) : 2,109 kWh per year or an average power output of 240.7 watts
- Montana (18,508 euro) : 2,691 kWh per year or an average power output of 307 watts.

Keep in mind that these windmills would perform considerably worse in a built-up area.

47 windmills to power a household

An average Dutch household consumes 3,400 kWh/year. Listed below is the amount of windmills required, and their total cost, to power a Dutch household entirely using wind energy:

- Energy Ball : 47 windmills (202,288 euro)
- Ampair : 14 windmills (124,950 euro)
- Turby : 14 windmills (298,900 euro)
- Airdolphin : 9 windmills (157,932 euro)
- WRE 030 : 9 windmills (265,608 euro)
- WRE 060 : 7 windmills (260,309 euro)
- Passaat : 6 windmills (55,434 euro)
- Skystream : 2 windmills (21,484 euro)
- Montana : 2 windmills (37,016 euro)

An average American household consumes almost 3 times more electricity than a Dutch household. Simply multiply the above figures by three.

Rotor diameter

At first sight, the results seem to indicate that the design of the windmill matters. However, if you combine these figures with the rotor diameter, it becomes clear that the concept of small windmills is fundamentally flawed. The turbines that score best, are simply the largest ones:

- Energy Ball : 1 meter
- Ampair : 1.7 meter
- Turby : 2 meter
- Airdolphin : 1.8 meter
- WRE 030 : 2.5 meter
- WRE 060 : 3.3 meter
- Passaat : 3.12 meter
- Skystream : 3.7 meter
- Montana : 5 meters

Windmills with a rotor diameter of 4 or 5 meters do not fit on most roofs, and are not easy to integrate in a built-up environment.

Size matters

Close to the test site stands a (relatively) large windmill with a rotor diameter of 18 meters. It delivers 143,000 kWh per year, or an average power output of 16,324 watts. It can power 42 Dutch households. This large windmill costs only slightly more than all small windmills combined (17 percent more, to be exact, or 190,000 euro), but it delivers almost 20 times more energy. This comes down to 4,523 euro per household.

Wind power rules, but small windmills are a swindle. Bigger is, in this case, better.

KDD (edited by Vincent Grosjean) / Thanks to Jeroen Haringman & Jaap Langenbach .

Comments (27)

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More :

Urban windmills harm the environment : In urban areas, small windmills will not even deliver as much energy as was needed to produce them.

Ecotech Myths

Low-tech Solutions

Obsolete Technology

Mixed links & updates at No Tech Magazine

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Sailing at the touch of a button

2009-04-13T21:36:26+02:00

Lloyd Alter at Treehugger talks about our article on cargo ships and wonders if it is time for a new age of sail. One reader comments that sailing boats require a much larger crew than today's cargo vessels, which would make a comeback of wind power unrealistic. Maybe, but these days, sailing boats can also be controlled by computers instead of sailors.

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If you want a revival of sail the ecotech way, you can have it.

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The need for a large crew to operate the rigs makes sailing ships not only expensive to operate, it also means that a significant part of the cargo space is taken up by cabins, provisions and water supplies. Sailings boats did better than rowing boats (which had a very limited range because of their even larger crew) but they were no competition for later steamboats and today's diesel ships, which can get along with only a handful of sailors.

Automated sail handling

The 1902 Preussen (pictured here yesterday) was the first ship to automate sail handling. It had no auxiliary engines for propulsion, but it made use of steam power for the operation of the winches, hoists and pumps. This limited the crew to 48 men. By comparison: the Kruzenshtern (picture above) a very large sailing vessel without mechanised control, has a crew of 257 men.

The Preussen had 5 masts (with a maximum height of 68 meters) and 47 sails (with a total surface area of 5,560 square meters or 60,000 square feet). It had a length of 147 meters (438 ft.) and a load-carrying capacity of 8,000 tons.

Today, sailing boats can be operated with even smaller crews. The Royal Clipper, a steel-hulled five masted cruise ship built in 2000 and inspired by the Pruessen (it is only slightly smaller), can be handled with a crew as small as 20, using powered controls. The Royal Clipper (picture below) is the largest sailing ship in service today (although it does have auxiliary engines).

In 2006, automated control was taken to the extreme with the Maltese Falcon, the yacht of Silicon Valley venture capitalist Tom Perkins. The 88 meter (290 foot) long luxury yacht can be operated by one man using a central control unit. A small crew is required for maintenance and fixing problems, but nobody needs to be in the rig during sailing.

Touch of a button

Handling, hoisting and lowering of the sails is done at the touch of a button - the sails roll into the mast. The Maltese Falcon (pictured below) has 3 masts (58 meters high) and a total sail area of 2,400 square meters (almost 26,000 square feet). It is about half the size of the Preussen.

The Maltese Falcon is equipped with the DynaRig technology, a concept that was developed in Germany by W. Prolls in the 1960s as a propulsion alternative for commercial ships in the face of a looming energy crisis. It was never applied then - the Maltese Falcon is the first proof-of-concept. Now some smaller versions have been designed, too.

High-tech materials

The DynaRig is a high-tech version of a "square-rigger", the kind of sail used by the Preussen. The main difference is that the yards (the horizontal spars) do not swing around a fixed mast but are attached permanently to a rotating mast. Only recent developments in high-tech materials such as carbon fibre have permitted this technology. The yards keep the sail in a fixed, wing-like form.

Contrary to a traditional sailboat, the rig of the Maltese Falcon scarcely shows any ropes or wires. But it does have dozens of computers and microprocessors, connected by 131,000 feet of cable. The Preussen is low-tech, the Maltese Falcon is ecotech.

Making money

The Maltese Falcon is a sumptuous yacht that is hard to qualify as environmentally friendly. Still, it demonstrates the effectiveness of powering very large boats with a modern sail, capable of being handled by the small crew necessary for a commercial cargo ship to have a chance of being profitable.

I prefer the low-tech way; higher taxes on fuel, lower taxes on labour. But if you want a revival of sail the ecotech way, you can have it.

KDD (edited by Vincent Grosjean)

Above: the Portuguese Sagres III.

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Related :

Cargo ships, then and now : which one is fastest?

The revival of the sailing ship : kitesurfing for cargo vessels.

Ocean liners : from London to New York in 3 days and 12 hours.

Trolleytrucks and trolleybuses : get wired (again)

The Kalakala : the art of slow travel.

The Ictíneo : a steam powered submarine.

The Aeromodeller II : camping in the clouds.

The Hennepin Crawler : macho pedal power.

Who killed the electric grid? Fast-charging cars.

Sailrockets & kiteboats.

Carrier pigeon beats internet : the revival of the sneakernet.

Low-tech solutions / Obsolete technology / Ecotech myths / Mixed links

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Cargo ships, then and now

2009-04-12T04:43:36+02:00

On an early afternoon last month, the Eugen Maersk (the world's longest ocean freighter at 1,300 feet) has left Rotterdam, the Netherlands, on the tail end of a journey from Shanghai. But the giant freighter is cruising at 10 knots, well shy of her 26-knot top speed. At about half speed, fuel consumption drops to 100-150 tons of fuel a day from 350 tons, saving as much as $5,000 an hour.

The German Preussen (picture above), the largest sailing ship ever built, was launched in 1902 and travelled mainly between Hamburg (Germany) and Iquique (Chile). It was rammed by a large steam vessel in 1910. A one way trip between Germany and Chile took the cargo vessel between 58 and 79 days. The best average speed over a one way trip was 13.7 knots.

One giant container ship can emit almost the same amount of cancer and asthma-causing chemicals as 50 million cars, study finds.

Picture credit.

Read more: Sailing at the touch of a button: Wind-powered, computer-controlled.