Low-tech Magazine

Medieval smokestacks: fossil fuels in pre-industrial times

The history of energy use in human civilisation is generally summarised as follows: from Antiquity until the start of the Industrial Revolution, people made use of the manual labour of both animals and humans, as well as biomass, sun, water and wind.

Next, all these renewable energy sources were replaced by fossil fuels: first coal, and later oil and gas. Uranium completed the picture in the second half of the twentieth century.

While this historical summary is basically correct, there were some - rather important - exceptions. Almost all of the leading economies in Western Europe during the last millenium relied on a large-scale use of fossil fuels such as peat and coal.

The bright future of solar powered factories

Most of the talk about renewable energy is aimed at electricity production. However, most of the energy we need is heat, which solar panels and wind turbines cannot produce efficiently. To power industrial processes like the making of chemicals, the smelting of metals or the production of microchips, we need a renewable source of thermal energy. Direct use of solar energy can be the solution, and it creates the possibility to produce renewable energy plants using only renewable energy plants, paving the way for a truly sustainable industrial civilization.

Pedal powered farms and factories: the forgotten future of the stationary bicycle

If we boost the research on pedal powered technology - trying to make up for seven decades of lost opportunities - and steer it in the right direction, pedals and cranks could make an important contribution to running a post-carbon society that maintains many of the comforts of a modern life. The possibilities of pedal power largely exceed the use of the bicycle.

Aerial ropeways: automatic cargo transport for a bargain

These days, we use them almost exclusively to transport skiers and snowboarders up snow slopes, but before the 1940s, aerial ropeways were a common means of cargo transport, not only in mountainous regions but also on flat terrain, with large-scale systems already built during the Middle Ages.

Cargo tramways can be fully or partly powered by gravity, and some deliver excess power that can be utilized to generate electricity or to drive cranes or machinery in nearby factories. Some innovative systems have been constructed in recent years.

Ropeway in Gdansk/Danzig, 1644

Boat mills: water powered, floating factories

The waterwheel was seen as the most important power source in the world, from the Middle Ages to the end of the nineteenth century. When smaller streams became saturated, medieval engineers turned their attention to larger rivers, eventually leading to the development of the hydropower dams that still exists today. Lesser known are the intermediate steps toward that technology: boat mills, bridge mills and hanging mills. Boat mills had already appeared in 6th century Italy and spread all over the world. Most of them remained in use up until the end of the 1800s, with some of them surviving well into the 1900s.

Lost knowledge: ropes and knots

Ropes and knots are among the most ancient and useful technologies ever developed by man, predating the wheel, the axe and probably also the use of fire. Today, they are fast on their way to become an obsolete technology.

Rings of fire: Hoffmann kilns

About a year ago we presented a medieval building technique that could save large amounts of brick and thus embodied energy in construction: timbrel vaulting. Turns out that there is also a 19th century brick and tile production technique that is surprisingly energy efficient: the Hoffmann kiln, a giant version of the medieval oven stove.

Wind powered factories: history (and future) of industrial windmills

In the 1930s and 1940s, decades after steam engines had made wind power obsolete, Dutch researchers obstinately kept improving the – already very sophisticated – traditional windmill.

The results were spectacular, and there is no doubt that today an army of ecogeeks could improve them even further. Would it make sense to revive the industrial windmill and again convert kinetic energy directly into mechanical energy?