Tag Archives: bicycling

Human Power: That Other Renewable

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Bike-powered peanut sheller and blender

Of all the renewable energy sources available today, one of them is constantly overlooked by modern society. It’s a shame, because this renewable energy is easy to harness, uses little space, and is complementary to wind and solar energy. I am speaking about that other, forgotten renewable: human power.

Using machines like a hand-crank, treadle, or pedal, human labor can be harnessed as mechanical or electrical work. The most common human-powered machine is the bicycle: mechanical work from a pedal is used to turn a wheel, which propels the rider forward. Bicycles, however, are not the only possible human-powered machines. With some clever engineering, human power has been harnessed to crank washing machines, plow fields, and saw wood. A bicycle can even generate electricity if equipped with a generator, voltage regulator, and battery. It can then power light bulbs, flashlights, laptops, and vacuum cleaners.

Hand-cranked and solar flashlight and radio


Hand-cranked red pepper processor

Unlike other renewable energy sources, human power requires active labor. Modern society, with its distaste for exercise in general, rejected human-powered machines for this very reason. That’s a shame, because human-power provides a nice complement to solar technology. Pedal-power can provide a handy back-up to photovoltaic panels on cloudy days. What’s more, pedal power can create short bursts of electricity, in contrast to the steady-stream of low power provided by solar panels.

An illustration involving an LCD monitor can provide perspective. A typical monitor requires around 100W of power to operate. After cloud cover and the earth’s tilt are considered, a photovoltaic panel might produce a power of around 25W/m^2 on average (1). So to power the monitor, we would need 4m^2 of solar panels. It only takes a single stationary bicycle, however, to generate 100W. Space is only needed for the bicycle itself and a few electronics, so the whole system can be contained in around one square meter. A fit cyclist, moreover, can produce even higher rates of sustained power — up to 200W in athletes. As a result, a well-trained cyclist can produce twice the energy of a photovoltaic panel in one-fourth of the space.

Pedal-power is not unreasonably expensive. A stationary unicycle can be built for under $250, and accompanying electronics can be purchased for around $400 (2). The combined total is $650, roughly the cost of similar solar panel installations.

The real cost savings, however, are for appliances that require only mechanical power. When there is no need to purchase expensive electronics, pedal power is clearly cheaper, since these machines can be built using only donated bicycles, spare hardware, and elbow grease. One NGO based in Guatemala, Maya Pedal, has taken discarded bikes and retrofitted them to make useful tools for local farmers. Old bicycles have been used to blend soap, pump water, grind flour, shell peanuts, and thresh grain. Not only has this removed the drudgery of agricultural work, it has also increased the income of local families. These projects promote development without burning extra gasoline or coal, all while recycling old garbage.

The Western world could learn a lesson. We chronically suffer from energy shortages, and we have no lack of people needing exercise. In the United States, more than one in four Americans are obese, and six in ten overweight. Cheap energy has allowed us to live sedentary lifestyles, which shorten our lifespans and waste trillions of dollars on unnecessary healthcare. If couch potatoes were forced to pedal for their television time, the rates of Western diseases — heart attacks, strokes, diabetes, and cancers — would rapidly plummet.

This is much better than going to the gym. Not only does gym membership cost thousands of dollars, but workout machines like treadmills actually waste additional energy to power. The average treadmill consumes 1500W of power — enough power to run 20 laptops. When people drive to the gym, moreover, they further add to greenhouse gas emissions. With human-power, they could instead burn their extra fat for productive purposes. Those calories might as well be used to wash clothes, blend smoothies, and generate electricity. Why not combat global warming while getting in shape?

Pedal-powered washing machine

Whether human power can truly make a difference depends on the efficiency of the exercise machine and the power demanded by your household. The average person can produce around 35-60W of power using a hand-crank, and 100W-120W using pedal power. Cell phones, flashlights, and watches can all be powered by hand-crank, while computers and televisions can be powered by pedals.

This sounds promising — that is, until you consider our monstrous demand for power. A medium-sized, window air conditioner uses around 1000W of power. To supply the energy for just that one AC unit, it would take a team of ten cyclists pedaling at full speed for the entire day. Once you add in laptops, televisions, clothes driers, washing machines, heaters, and light bulbs, human power becomes woefully inadequate. It would take a legion of cyclists to support the typical American home.

Storing generated electricity is a problem as well. Most pedal generators use lead-acid batteries, which store energy for later use. Devices can then be plugged into the battery rather than directly to the exercise machine. This helps avoid the awkward situation of having to simultaneously pedal while using your laptop. But as Low Tech Magazine points out, lead-acid batteries require massive amounts of energy to manufacture. Sulfuric acid can also cause severe burns, and lead can cause birth defects and brain disorders. Even pedal-powered electricity, then, isn’t perfectly green.

This limitation can be largely overcome by simply transmitting work mechanically rather than electrically. One clever hobbyist retrofitted his bicycle to spin washing machines using only pulleys and belts. The Human Powered Home, a compendium of do-it-yourself pedal-powered machines, provides plans for mechanically connect your bicycle to a grain mill, sewing machine, and tool sharpener. With a little ingenuity, the mechanical applications of pedal power are endless.

Pedal-powered jig saw

Despite its flaws, human-powered electricity can still contribute to sustainable living. Every renewable technology has its limitations, and a human-powered generator is no exception. They may not be perfectly green, but neither are solar panels. When used properly, the benefits of renewable, off-grid electricity can outweigh the harm caused by pedal-power electronics.

Generating your own electricity can allow you to live off the land, which dramatically reduces your carbon emissions. One difficulty with living on rural, undeveloped land is the lack of grid electricity. Pedal power, along with photovoltaic panels, can provide electricity without an expensive connection to the utility company. One Laptop Per Child, for instance, has taken advantage of human power to design off-grid laptops. Students in remote villages often lack access to electricity, but one minute on a hand-crank can provide enough energy for ten minutes of laptop use.

Yet the most profound impact of human power is not the generated electricity itself, but rather the conservation ethic it instills. Producing electricity is hard work. When we hook up an appliance to a power outlet, we are blind as to how much energy we are truly wasting. But if we had to pedal forty-five minutes for each hour of television we watched, we would be more conscious about our electricity usage. We would never have to be reminded to turn off our lights or to sleep our computers, and few would dream of using an air conditioner. Ultimately, it’s conservation — in addition to our feet — that will provide us with the power to lower our carbon footprint.

Do-it-yourself bicycle-power plans are the most affordable and have the lowest environmental impact. There are also some commercially-available attachments. They are expensive, however, and may actually waste more energy than they produce. I encourage you to build your own instead.

  1. Sustainability: Energy: Without the Hot Air generously estimates that a solar panel in Britain produces around 22W/m^2 on average. Low-Tech Magazine estimates a power capacity of 100-150W for average cyclists and up to 300W for athletes.
  2. The Pedal Powered Prime Mover is one unicycle designed especially for pedal power. It costs around $100-$250. The exact electronics will vary depending on your needs.
  3. Photo credits: Alan Levine, CC BY. Engineering for Change, CC BY. AIDG, CC BY-NC-SA. AIDG, CC BY-NC-SA. Donkeycart, CC BY-NC. Bruce Turner, CC BY.

Carrying Heavy Loads, Sans Car

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If you sell your car, you’ll need to devise a method to carry heavy loads. Even minor loads can become troublesome when you’re not prepared. If you eat at home frequently, expect to carry at least 50lbs. of groceries each week. If you have children, you’ll need to shuttle your little ones to school, to church, and to sports practice. And when you buy furniture or appliances, you’ll need to transport them into your house. So how, exactly, do you haul a refrigerator into the kitchen if you don’t own a car?

I’ve been living without a car for about two years now. During that time, I’ve experimented with dozens of unconventional methods for carrying heavy loads over long distances. I hope this article inspires you to customize these set-ups to fit your own needs. Trust me: with a ingenuity and elbow-grease, you can move practically anything sans car (1).

Here’s a list of my favorite tactics:

Stop Shopping

Buying too much stuff clutters your house, wastes your money, and hurts the environment. I have stopped shopping altogether for half a year now (except for food, of course).

Order it online

Many brick-and-mortar shops now offer online ordering and home-delivery. Take advantage of it! Walmart, Home Depot, Target, Sears, Macy’s, Kohl’s, Dell, and Apple now deliver directly to your home. Sam’s Club and Costco seem to only deliver to business districts, but perhaps you can negotiate with the local store manager. Here’s a massive compilation of online grocery chains that offer home delivery. You should consider Safeway, AmazonFresh, FreshDirect, and Peapod. Most chains only offer delivery in limited locations, so ask around. Sometimes, as with the case of Albertsons, home-delivery is offered only in select areas so it’s not widely advertised.

You can definitely get home-delivered organic food. There are large organic chains like Diamond Organics as well as small-scale, local farms. Local Harvest, Eat Wild, and the Eat Well Guide are have enormous listings of local farms that deliver. I used to be part of a CSA program that offered home delivery. Currently, I’m getting free-range chicken eggs delivered to my apartment from a farm in Miaoli.

Home delivery can be expensive (expect a 50-100% markup). However, it can save you a lot of time, which you can use for relaxation or for work (to earn more money). At one point, I even hired a personal assistant to shop for me (via Care.com). It was cheaper to hire a personal grocery shopper at $15/hr than it was to pay for insurance and gas. In the process, I freed up a lot of time.

Rent a car

Don’t own a car just to move large furniture; renting is much cheaper. You can even use frequent flyer miles or credit cards rewards points to pay for rentals.

For about a year, I was a member of ZipCar. I used it every other week for grocery shopping. It cost about $30 for 3 hours, which was enough time to round up all the groceries I needed for two weeks. I didn’t have to take out a car loan, nor did I have to pay for gas, insurance, or campus parking. I later experimented with renting a car for church on Sundays. This tactic is extremely convenient if you have kids.

Recently, I discovered I overpaid for car rentals. Experienced travelers can get full-day rentals for less than $30. With rewards points, you can rent a car for less than $15 per day.

Transform your bicycle into a workhorse

I upgraded my tandem and my road bike so each one can easily handle over 75lbs. of groceries. My favorite method is to attach a grocery basket
to the handlebars, then mount a rack
on the rear frame and attach baskets to the side. Here’s a photo of my set-up for the tandem bike.

(Left) Set up of our own tandem bike. (Right) Tandem bike with a trailer.

Most of my groceries fit in the front and side baskets, but when I need extra capacity, I can tie boxes onto the bike rack using a bungee cord. Even when fully loaded, the bikes still give a comfortable ride. Bike shops are extremely helpful for installing these custom parts.

If you do a lot of shopping, you can invest in a grocery trailer. Trailers attach to the bike frame and let you haul over 200lbs. on a single trip. You might even be able to haul a refrigerator with just a single bicycle.

Carrying children is trickier. If you have an infant, you can carry him with a child seat attached to your bike frame. When he grows older, he can ride with you in tandem with a special bike trailer attachment. The tandem bolts onto your existing bike seat. The kids won’t be able to steer, but they’ll still get some exercise.

If you have a big family, you’ll definitely want to invest in a child’s trailer. The bonus of having a child’s trailer is that you can use it as a grocery cart when you go shopping.

Hsinya and I don’t have any kids (yet), so we’ve never tested this out ourselves. However, we have experimented with tandem bikes. I recommend either a collapsible tandem or a detachable trailer. Don’t buy a full-sized tandem: they’re too bulky to pack up into a van or a bus.

(Left) Bike trailer. (Right) Bike with a child seat.

Get a Hand Truck

It’s better than borrowing a grocery cart. Find one that can carry over 200lbs., but can collapse to the size of a textbook. Hand trucks/folding shopping carts can be combined with public transit to shorten walking distance. However, hand trucks can be difficult to use if sidewalks are in disrepair (or non-existent, like in Taiwan). In these cases, I just use my backpack and travel bags.

(Left) A hand truck. (Right) A folding shopping cart.

The particular solution doesn’t matter; just make sure you find one that works for you. It has to be cost-effective, simple, and convenient. If it’s not a solution you can live with on a weekly basis, you’ll find yourself wanting to own a car all over again.

Keep in mind that hauling heavy loads will always be a slight challenge without a car. Getting the perfect solution takes experimenting, so don’t give up quickly. Remind yourself of the millions of dollars you’re saving, as well as all the energy you’re conserving. You’re helping the environment and getting a good workout along the way.

With a little ingenuity and determination, you’d be surprised with what you can come up with.

  1. Michael Bluejay uses his bicycle to move to his new place. This article made me laugh.
  2. Photo attributions in order of photo appearance: Robert S. Donovan, CC BY; our own photo; tandemracer, CC BY; Howard N2GOT, CC BY;Mark Stosberg, CC BY-NC-SA; Hand Truck Sentry System, CC BY; ABMJG, CC BY-NC-ND; Foxtongue, CC BY.

Escaping High Oil Prices

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Today, the average price of gas in the USA is $3.29 per gallon. It sounds expensive, but it’s actually quite cheap compared to prices in the rest of the world. In Japan and Korea, gas costs around $5.50 per gallon. In Hong Kong, Germany, and Denmark, gas can cost as much as $7.50 per gallon. Filling up a 16-gallon tank in a mid-sized car can easily cost over $110 in Norway. To put that in perspective, $110 can pay for two weeks worth of groceries.

At $3.29/gallon, you could be spending $2000 each year in gas prices alone if you commute 30 miles each day to work (1). If two people commute separately, that’s $4000 each year. And there’s more awful news to come: the price of oil will only continue to increase. It’s a matter of basic economics: demand is increasing, but supply is running out.

Petroleum is a limited, non-renewable resource. This means that oil production follows a curve: it starts slow, hits a peak, and then begins to trail. Oil engineers predicted this phenomenon in the early 1950s—and this may be the decade we may finally reach peak oil. Soon thereafter, global oil production will taper off. Already, most easy-to-reach oil supplies have been exhausted. Oil companies are now increasingly resorting to offshore and tar sands oil extraction, which are both expensive and harmful to the environment. Yet while supply is decreasing, demand for oil is exploding. In particular, the burgeoning middle classes of China and India are acquiring a taste for motor vehicles. With a billion cars worldwide today, and tens of millions more added each year, the price of fuel will skyrocket.

Oil production peak by country. (from US Department of Energy)

Our current era of cheap, unlimited energy is quickly coming to an end. By the end of this decade, the average household could be spending $8000+ on gasoline each year just to commute to work. Our society’s driving habits will change—if not for environmental reasons, then at least because of the price.

The best strategy for dealing with the upcoming energy crisis is to wean yourself off of petroleum. Live with less gasoline so that rising fuel prices won’t affect your standard of living. Not only will you help reduce pollution, you’ll be saving thousands of dollars, too.

Switch over to mass transit whenever you can. They conserve fuel and ultimately conserve you money. A $65 monthly bus pass could save you $100 each month in fuel costs alone, or $1200 each year (2). If you can live without a car, you can save another $4000 each year in auto insurance, car payments, and parking fees. You’ll also save time; instead of fighting traffic, you can read, rest, or relax.

If you’re willing to totally unplug from the oil economy, you can start bicycle commuting . By cycling, you can save $6000+ each year. You don’t even need a specialized bicycle; just use what you have. In fact, if you live close enough, you can just walk. Both tactics will save you money while providing exercise.

For decades, we’ve been willfully ignorant about the fact that oil is a limited resource. We pretended that gas pumps had a supply that could never end. But within a decade, many of us may be forced to live car-free out of economic necessity. We didn’t pay attention to conservation in the past; but today, we can’t afford not to.

  1. Assumptions: $3.29/gallon, 30 miles 1-way implies 60 miles round-trip, 5 days per week, 50 weeks per year, average mileage is 25 miles/gallon: $3.29/gallon × 30 miles × 2 (round-trip) × 5 days/wk × 50 wks/yr ÷ 25 miles/gallon = $1974/yr. Per month, it’s $1974÷12 = $164.5. For two commuters, it’s $1974 &multiply; 2 = $3948/yr. If gas rises to $6.59/gallon (doubling in price), the cost of fuel for two commuters is $7896/yr.
  2. A Los Angeles monthly bus pass is $75, and Orange County’s is $55. If the average bus pass is $65/mo., the difference between gasoline price and bus fare is $164.5 – $65 = $99.5. If we roughly estimate the cost of auto insurance ($1550), parking ($500), and car payments ($200/mo. &multiply 12mo. = $2400), the additional cost of car ownership is $4450/yr., not including the cost of maintenance and vehicle registration fees.