The Human Power Plant investigates the possibilities of human energy production in a modern society. In our first case study, we plan to convert a 22-floor building on the campus of Utrecht University into an entirely human powered student community.
The Willem C. Van Unnik building is the tallest building on the campus of Utrecht University in the Netherlands. The concrete, steel and glass monolith, which occupies a central position on the campus, was built in the late 1960s and has been mostly empty for years. Maintaining it is an important cost for the university, who owns the building.
The Human Power Plant proposes to turn a problem into an opportunity. The University of Utrecht has the ambition to become CO2-neutral in 2030. The ecological footprint of the human powered Van Unnik student community will be close to zero, and the building is already there.
Each student generates the electricity that's used in his or her own room. Research has shown that students are most attached to their phone, their laptop, and their lighting. The operational electricity use of these modern technologies is relatively low. The students will be generating energy for only 1 to 2 hours a day in order to use their most cherished devices.
Each room is equipped with a box-bed, which provides heat insulation during the night. The rest of the room can be warmed by the body heat coming from the lower communal power generating floors. By opening the vents of the heat distribution pipe, students can release the warm air into the room. For extremely cold days, students can plug a body suit into the vents, which results in a direct heating of the body.
The human powered student building has 22 floors and no passenger elevators. In many tower buildings, the stairs get rarely any use. In the human powered student tower, they are teeming with life. Climbing the building at an easy pace, one step at a time, requires roughly 30 seconds per floor. If this speed can be sustained until the top floor, climbing the whole building would take 11 minutes.
Running instead of walking up the stairs could greatly increase travel speed. The best athletes in the yearly Empire State Building Run climb 86 floors in 10 to 12 minutes. At such speeds, it would take only 3 minutes to climb the entire human powered student building -- quicker than an elevator, which usually stops along the way. Going down the stairs would go even faster when jumping and swinging around corners.
Providing 750 students with one hot shower per day would require a workforce of 750 students generating power for 10 hours per day. In other words, the complete student population would be working all day to provide everyone with a hot shower. This makes no sense. Therefore, students only take a 3-minute hot shower every 3 days. In between, they are encouraged to do more quick washes at the sink, or to take cold showers.
Energy use for doing the laundry is reduced significantly by washing clothes in cold water; Between 80 and 90% of the energy use of a washing machine is used to heat the water. In recent years, manufacturers have found ways to create detergents that work very well in cold water. Furthermore, the students are advised to wear woolen clothing, which needs to be washed less often and preferably in cold water.
Three floors of the human powered student building are taken up by the central human power plant, which is run by the entire community. The energy that's produced here is used to warm the water, run the refrigerators, flush the toilets, and power the lights and other devices in the communal spaces. The body heat from the power producing students is piped throughout the building and into communal spaces and individual student rooms.
The power generation floors are equipped with various individual and communal exercise machines. Most power is produced by large treadmills and capstans, which are each operated by up to a dozen people at the same time. The power producing students are encouraged by live musicians. The use of music during physical labour -- to pass the time, to coordinate timing, or to protest against work conditions -- has a very long tradition.
The food waste from the kitchen and the excrements of 750 students are used to produce biogas that supplies the energy for cooking. On the other hand, energy use for cooking is reduced substantially by communal food preparation and the use of fireless cookers. After food is brought to a boil on a biogas fire, cooking pots are placed in a heavy insulated container, which keeps the cooking process going without the need for additional energy.
The use of excrements for biogas production requires the installation of vacuum toilets. These toilets separate the solid waste from the urine and transport it to the biogas installation in the basement with the use of very little water. Operating a biogas digester is labour-intensive: food waste needs to be collected, and all biodegradable material needs to be mixed with water, fed in the digester, and stirred.
Humans need extra food when they produce power, and producing this food also requires energy. Assuming a typical Dutch diet, one kilowatt-hour of human generated electricity produces up to 30 times more greenhouse gases than one kilowatt-hour of grid electricity. However, the average Dutch person eats too much and could produce power for 2 to 3 hours without extra food intake.
To further limit the CO2-emissions of food, the students have opted to produce their own cheese and use the waste product of that process to make protein shakes. These are convenient because they allow active people to ingest sufficient proteins without grilling steaks and steaming vegetables almost continuously. To add surprises to the diet, students on cooking duty go dumpster diving in the city, mainly at the big supermarkets.
How long the students need to exercise depends only on their demand for power. Because the users of energy are also the producers of energy, there’s a strong incentive to reduce energy demand. The working schedules for communal energy production are negotiated and set up by the students themselves, who are in total control of their human powered community. The energy use in the individual rooms is decided by each student separately.
The Human Powered Student Building is equipped with a gravity battery in one of the former elevator shafts. It smooths out peak energy demand, which allows to spread the power generating workforce more evenly throughout the day. The energy storage also makes it possible to produce energy only during the day and still have power at night, for example to operate the refrigerators.
Located on the roof of the Human Powered Student Building are ten Skystream windturbines. Together, these can supply 20 kW of power with a strong breeze (11 m/s). Whenever it’s windy, human energy production is taken over by the wind turbines. During windy periods, students thus enjoy free and effortless energy use. Daily working duties are reduced or eliminated.
If the wind blows long and hard enough, and the maximum capacity of the hydraulic power storage is reached, the student building has an oversupply of energy. This excess energy is used to have fun on the roof, which has jacuzzis, large screen televisions, powerful game computers, and a sound system. During windy periods, students head for the roof to enjoy sustainable decadence.
Low Energy Use
A human powered student community has potential for a reduction in energy use. If students have to generate their own power, they are much less likely to waste it. How far would students go to reduce their efforts? Would hot showers go out of fashion? Would salads be the next culinary trend? Would typewriters make a comeback?
Energy use is also lowered by encouraging the communal organisation of daily household tasks, just like in the old days. Finally, the human powered student community applies low-tech solutions, such as fireless cookers, thermal underclothing, and heat exchange showers, which all maximize comfort in the context of a limited energy supply.
The Human Powered student community is not only 100% sustainable, it also promotes better health and fitness, as well as more social cohesion.