From the earliest civilisations right up to the start of the Industrial Revolution, humans used sheer muscle power, organisation skills and ingenious mechanics to lift weights that would be impossible to handle by most power cranes in operation today.
Continue reading "The sky is the limit: human powered cranes and lifting devices" »
The ingenious low-cost vertical farms of Willem Van Cotthem are within reach of everybody.
Continue reading "How to make your own low-tech vertical farm" »
During the Second World War, almost every motorised vehicle in continental Europe was converted to use firewood.
Wood gas cars (also known as producer gas cars) are a not-so-elegant but surprisingly efficient and ecological alternative to their petrol (gasoline) cousins, whilst their range is comparable to that of electric cars.
Rising fuel prices and global warming have caused renewed interest in this almost-forgotten technology: worldwide, dozens of handymen drive around in their home-made woodmobiles.
Continue reading "Wood gas vehicles: firewood in the fuel tank" »

For many centuries, canal boats were propelled by men, horses or mules on the towpath beside the water. Before diesel power took over, engineers developed several interesting methods powered by electricity: trolleyboats, floating funiculars and electric mules. Many of these ecological solutions could be applied today instead of diesel engines. Because of the very low energy requirements, they could easily be powered by renewable energy, generated on the spot by water turbines located at sluices. One trolleyboat line is still in use.
Continue reading "Trolley canal boats" »
Increasing the share of renewable energy will not make us any less dependent on fossil fuels as long as total energy consumption keeps rising. Renewable energy sources do not replace coal, oil or gas plants, they only meet (part of) the growing demand.
Continue reading "How (not) to resolve the energy crisis" »
Some readers have observed that we haven't paid any attention to one of the most low-tech innovations ever - the humble bicycle. We noted the sex-appeal of pedal power (and this concerns both men and women), but that's about it. So, since you asked for it, here is our concise but clear point of view on these human powered two-wheelers.
Continue reading "Cars: out of the way" »

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.
Continue reading "Rings of fire: Hoffmann kilns" »
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?
Continue reading "Wind powered factories: history (and future) of industrial windmills" »