LOW-TECH MAGAZINE

How Much Energy Do We Need?

Because energy fuels both human development and environmental damage, policies that encourage energy demand reduction can run counter to policies for alleviating poverty, and the other way around. Achieving both objectives can only happen if energy use is spread more equally across societies.

However, while it’s widely acknowledged that part of the global population is living in ‘energy poverty’, there’s little attention given to the opposite condition, namely ‘energy excess’ or ‘energy decadence’. Researchers have calculated minimum levels of energy use needed to live a decent life, but what about maximum levels?

Bedazzled by Energy Efficiency

To focus on energy efficiency is to make present ways of life non-negotiable. However, transforming present ways of life is key to mitigating climate change and decreasing our dependence on fossil fuels.

How to Run the Economy on the Weather

Before the Industrial Revolution, people adjusted their energy demand to a variable energy supply. Our global trade and transport system -- which relied on sail boats -- operated only when the wind blew, as did the mills that supplied our food and powered many manufacturing processes. 

The same approach could be very useful today, especially when improved by modern technology. In particular, factories and cargo transportation -- such as ships and even trains -- could be operated only when renewable energy is available. Adjusting energy demand to supply would make switching to renewable energy much more realistic than it is today.

How (Not) to Run a Modern Society on Solar and Wind Power Alone

While the potential of wind and solar energy is more than sufficient to supply the electricity demand of industrial societies, these resources are only available intermittently. To ensure that supply always meets demand, a renewable power grid needs an oversized power generation and transmission capacity of up to ten times the peak demand. It also requires a balancing capacity of fossil fuel power plants, or its equivalent in energy storage. 

Consequently, matching supply to demand at all times makes renewable power production a complex, slow, expensive and unsustainable undertaking. Yet, if we would adjust energy demand to the variable supply of solar and wind energy, a renewable power grid could be much more advantageous. Using wind and solar energy only when they're available is a traditional concept that modern technology can improve upon significantly.

Could We Run Modern Society on Human Power Alone?

Unlike solar and wind energy, human power is always available, no matter the season or time of day. Unlike fossil fuels, human power can be a clean energy source, and its potential increases as the human population grows. In the Human Power Plant, Low-tech Magazine and artist Melle Smets investigate the feasibility of human energy production in the 21st century.

To find out if human power can sustain a modern lifestyle, we are designing plans to convert a 22 floors vacant tower building on the campus of Utrecht University in the Netherlands into an entirely human powered student community for 750 people. We're also constructing a working prototype of the human power plant that supplies the community with energy.

The Human Power Plant is both a technical and a social challenge. A technical challenge, because there's a lack of scientific and technological research into human power production. A social challenge, because unlike a wind turbine, a solar panel or an oil barrel, a human needs to be motivated in order to produce energy.

Heat Storage Hypocausts: Air Heating in the Middle Ages

Hot air vents in the floor of the Maulbronn monastery. Source: "Das Kloster Maulbronn. Geschichte und Baugeschichte.", Ulrick Knapp, 1997 / Via Spiegel 2016.

The Romans are credited with the invention of the first smoke-free heating system in Western Europe: the hypocaust. Until recently, historians had assumed that its technology was largely lost after the collapse of the Roman Empire. In fact, however, it lived on in large parts of Europe, and was further developed into the “heat storage hypocaust”, an underground furnace on top of which granite stones would be piled, to then release hot air through vents in the floor. By this means, a room could be kept warm for days with just one firing of the hypocaust's furnace.