Battery used Battery charging

Power Water Networks

Hydraulic power transmission is very efficient compared to electricity when it is used to operate powerful but infrequently used machines.

Reinventing the Greenhouse

Contrary to its fully glazed counterpart, a passive solar greenhouse is designed to retain as much warmth as possible.

Fruit Walls: Urban Farming in the 1600s

From the sixteenth to the twentieth century, urban farmers grew Mediterranean fruits and vegetables as far north as England and the Netherlands, using only renewable energy.

How to Build a Low-tech Internet

If we want the internet to keep working in circumstances where access to energy is more limited, we can learn important lessons from alternative network technologies.

The 4G Mobile Internet That's Already There

These days, so many households have a WiFi-router installed that sharing the signal of these devices could provide free mobile internet access across densely populated cities.

Why We Need a Speed Limit for the Internet

The energy use of the internet can only stop growing when energy sources run out, unless we impose self-chosen limits.

Garum: Fermented Fish Sauce for the Ancient Roman Masses

Fish fermentation allowed the ancient Romans to store their fish surplus for long periods, in a time when there were no freezers and fishing was bound to fish migratory patterns.

Water Johads: A Low-Tech Alternative to Mega-Dams in India

Before the British arrived, people on the subcontinent used traditional low-cost, low-tech engineering to collect rainwater for thousands of years.

How Sustainable is Stored Sunlight?

Energy storage is often ignored when scientists investigate the sustainability of PV systems.

How Sustainable is PV solar power?

Almost all solar PV panels are now produced in China, where the electric grid is about twice as carbon-intensive and about 50% less energy efficient than in Europe.

Radiant & Conductive Heating Systems

Radiant and conductive heating systems make energy use independent of the size of a room or building.

How to Keep Warm in a Cool House

If we are looking for quick and substantial energy savings for existing buildings, then local heating systems deserve our closest attention