About a quarter of the existent wind turbines would suffice to power as many electric velomobiles as there are people.
A car with a top speed of 270 km/h can be driven anywhere on Earth, while an electric velomobile with an electric assistance of up to 50 km/h is illegal is most countries.
A cargo cycle is at least as fast as a delivery van in the city - and much cheaper to use.
The Spanish botijo is a water bottle that cools itself, without electricity.
Modern research, which combines ancient knowledge with fast computing techniques, shows that passive solar cities are a realistic option, allowing for surprisingly high population densities.
For being such a seemingly ordinary vehicle, the wheelbarrow has a surprisingly exciting history.
The old-timers on these pictures are not moving furniture or an oversized load. What can be seen on the roof is the fuel tank of the vehicle - a balloon filled with uncompressed gas.
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.
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.
The present approach to pedal power results in highly inefficient machines.
The possibilities of pedal power largely exceed the use of the bicycle.
From the 1870s onwards, pedals and cranks were attached to tools like lathes, saws, grinders, shapers, tool sharpeners and to boring, drilling and cutting machines.