Human Power
Electricity and human development coexist seemlessly in so-called developed countries (with UNDP's human development index: HDI at or above 0.75); whereas in so-called developing countries an electric grid is not available in the majority of places and when it is available, it is usually very unreliable. Consider the following graph:
It is within the yellow box where human power would have a place. This is easier understand by comparing Average Electrical Power and Human Development Index as in the following graph:
All the countries at or below 30 Watts/capita of average power means that small amounts of electricity generated (even from human power) can make a dramatic effect on human development. This is because to have electricity is to (1) have vacinne refrigerators and lights for surgery, (2) have lights and copy machines for schools, and (3) cell phones and internet for businesses. There is a potential for human power to play a role in some countries between 30 W/capita and 100 W/capita, but is not significant for countries above 1000 W/capita (say, the United States).
Human Power compared to Solar Panels
In the United States, solar panels are not begin purchased by consumers for large-scale electricity generation for many reasons. In Africa, the main reason for not choosing a solar panels is because they are too expensive and/or the level of theft risk is high. Consequently, in Uganda solar panels are used for critical purposes (i.e. lighting for surgery) or when a donor offers the equipment. When comparing a human powered bicycle generator system to a solar panel, Prof. Makanda and Dr. Mechtenberg came up with the following product attributes:
Make sure to visit the community blog to keep up-to-date on how other communities are starting to design, build, and use the bicycel generator. Whether this device is used soley or hybridized with solar panels depends on the consumers ability-to-pay for the various systems: both in terms of capital and maintenance costs. It is obvious there is a need for human powered lighting and radios for critical crisis situations, but beyond this level, who knows... only time will tell.
123's of Human Power Calculations
Comparing rates of energy consumption for humans depends on the type of activitiy and is well understand within kinesiology research. It is known that in the United States, many human activities during the day can be below 2000 Cal/day (or 98 W). Meaning that these people who sit at computers all day need to go to exercise gyms to consume more food energy or s/he needs to eat less than 2000 Cal/day.
However, in Africa and other places where electricity is not readily availabe, human activity requires them to eat more or to rest after work. The question then becomes which human activity is more efficienty: (1) human activity A with electricity or (2) human activity B without electricity. Imagine the following cases:
Human Activity Efficiency Comparision 1
For example, take Mrs. Muyonjo, Women of Uganda Network, Housewife Designs Mobile Phone Charger website. She bikes twenty miles to charge her cell phone battery. Assuming she bikes 10 mph on rough roads (60 Watts rate of work), it takes her 4 hours to go get her battery charged, and come back home. She outputs approximately 240 Wh of mechanical energy making this trip and needs to consume 1.1 kWh of chemical food energy for this human activity. However, if she was to ride a bicycle generator (60 Watts rate of work), she could charge her cell phone in 2 hours at home (30 Wh with 50% efficiency of bicycle generator), save energy, and have two more hours for an afternoon activity like enjoying life without physical effort (biking for two hours = 0.55 kWh plus 0.18 kWh of inactivity). Thus she would need to consume (A) 1.1kWh of energy for biking to and back from the nearest Independent Power Producer (IPP) to charge her cell phone versus (B) 0.73 kWh to bike on a bicycle generator at home and then rest.
Human Activity Efficiency Comparision 2
Imagine this idea (human activity efficiency) in terms of walking to watch a football game at a local video hall. If it takes an hour to walk to the video hall for a group of ten guys from the village, they output approximately 200 Wh (there and back) each or 1.2 kWh. If instead each bikes ten minutes on a bicycle generator directly connected to the television (100 W), then they would only consume 0.80 kWh (with 50% efficiency for bicycle generator) for four hours. The energy for the group to walk is 1.2 kWh and more than the group taking turns biking on the bicycle generator which is 0.80 kWh. There are a myriad of potential strategies from pumping water to cooking with a family owned and operated merry-go-round generator to a multi-use community-based pavilion where the energy consumed with human power generated electricity is less than the energy consumed without electricity.
Back-up Human Power for Critical Electricity Needs
Although the human power efficiency is important to consider, the real thrust of the issue rests on electricity crisis situations. The most pressing of these happens when the electric grid goes off during surgery. It is during these situations that Dr. Mechtenberg has collected ethnographic stories from various hospitals in Uganda and Ghana when electricity goes off and the back-up generator fails. In Ghana, there was a story of a man during open heart surgery where the grid failed, the generator failed, and then the flashlight's batteries were dead. The man could not quickly be sewn-up and therefore did not survive due to electricity failure. In these cases, as well as many other less dramatic cases, a human powered back-up electricity generating device is incredibly important.
David Butcher - Human powered examples
Since seeing is believing, I have collected a set of YouTube videos to watch David Butcher run a set of electrical consuming devices. From laptops to TV to washing machines and LED lights, the bicycle generator can power electrical equipment. If you are interested in more of his work, please see his web site. Hopefully in time, we will have a collection of videos from Uganda and Keyna uploaded to the website so that you can see and believe that this is possible anywhere!
Human Powered Office Example
One amazing and compelling story comes from the David Butcher who runs his laptop and copy machine at Golden Gate Park's 2007 Earth Day.
In this example, he prints fliers from his laptop run from his bicycle generator.
Human Powered Electric Drill
For anyone who has used an electric drill, you know that the electric drill is more precise than a screw driver.
In this example, the bicycle generator creates enough electricity to power a drill. In fact, most saws and drills with this level of electric power would be doable.
Human Powered TV
For anyone who loves watching football, you know that when the electric grid is off then you might have high demand to pay for electricity from a diesel or gasoline generator. However, what about sharing the biking requirements with friends who are watching the TV with you.
In this example, the bicycle generator creates enough electricity to power a TV. Since this TV is big and not efficient (i.e. it is a CRT and not a flat screen), then the person has to pedal harder than a smaller or more efficient TV.
Human Powered Lighting
It goes without saying that if laptops, TVs, electric drills, and washing machines can be run off of human power, then lights can be as well. The real issue here is that the lighting should be LEDs. The type of lights we have been using in Uganda are Taigeer. We used the rechargable flashlights/torches and reconnected them to be either (1) surgical lamps for hospitals and/or health clinics, (2) lights for schools, and (3) lights for schools.
Human Powered Washing Machine
For everyone who has every had to wash clothes by hand, you might really enjoy this device better.
In this example, it would depend on whether or not someone prefers to bike or to run their hands. Personally, I would rather bike and read a book to wash clothes rather than bend over and rub my hands with soap.
Human Powered Electric Blanket
For those who live in cold climates and/or during an ice storm when the electric power has gone out, you might really enjoy this device better.
In this example, one has the idea that any electric device that is within the human power abilities can be powered by human power. The real question is whether or not the device is in high enough demand or whether or not this device increases human activitiy efficiencies.