Tag Archives: electricity

Hang Dry Your Clothes

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Clothes dryers are unnecessary luxuries that waste both energy and money. On one hand, they harm the environment since natural gas or coal must be burned to dry clothes (electricity comes from burning coal). On the other hand, clothes dryers are expensive. The cost of energy for a single load of laundry is around 40¢, which adds up to around $160 per year for a typical household (1). Yet besides the price of fuel, there’s also the cost of the clothes dryer itself, which is around several hundred dollars even before installation. The clothes dryer, then, is an expensive energy guzzler, a runner-up to the heater and air-conditioner.

Heat production inherently requires lots of energy, so even an energy-efficient clothes dryer wastes massive amounts of fuel. Producing any heat at all, however, is a silly idea; most of us enjoy an abundance of free heat each afternoon. Wherever there is sunlight, clothes can be hung-dry to harness no-cost natural sunshine. Hang-drying your laundry is minimalist, cheap, and low-tech — no drying machines or solar panels necessary.

Besides saving money on your energy bill, there are other reasons to avoid the clothes dryer. Clothes that are tumble dried get damaged quickly and need replacing more often. The tumble dry cycle, moreover, leads to static charge buildup (yes, you could add fabric softener, but why not just get rid of the source of the problem?). And most importantly, clothes dryers produce extra heat, making hot days more unbearable. When I used to live in sunny Southern California, daytime temperatures often exceeded 90°F (32°C) during the summer. When people used clothes dryers, it would feel 10°F (5°C) hotter inside the laundromat than outside. The sweltering heat would have been perfect for hang-drying laundry, but sometimes our culture forgets the painfully obvious.

Clothes can even be dried when it’s raining. If there’s no sunlight, simply hang your wet clothes indoors and allow the moisture to evaporate. Just make sure that the clothes get plenty of aeration. Sometimes, I use a fan to accelerate drying. I never let the occasional rainy day stop me from hang-drying my clothes during the rest of the year.

It’s simple to do laundry without a clothes dryer. Here are a few different methods:

  1. Use a simple clothesline. A sturdy clothesline can be made of metal wire, plastic, or natural fibers. Tie each end of the clothesline to a solid support (bars, poles, trees), then use clothespins or clothes hangers to attach your clothes to the line. In my house, we tie a piece of braided wire to the bars on our windows to support the clothesline. You probably don’t need to buy any equipment for this setup.
  2. Buy a retractable clotheslines. There are a few luxury models available that are much more elegant than my makeshift clothesline. Retractable clothesline fold away nicely for people living in tiny apartments.

    3. A 4-line retractable clothesline

  3. Buy a clothes rack. There are two types: the traditional, heavy-frame variety, and the newer, collapsible models. Both types will provide a vertical support for when you can’t find a pole to tie your clothesline to.

    A collapsible drying rack

    Before we gave away our possessions, we used to own a lightweight, folding clothes rack. It was perfect for our tiny apartment, since it was designed for high-density stacking, allowing us to dry plenty of clothes even on a tiny patio. Hsinya used them for delicate clothes that had to be laid flat to dry (some delicate fabrics stretch under their own weight when hung). It was flimsy, however, so it quickly broke under the weight of wet clothes.

    A sturdy collapsible clothes rack vs a flimsy broken one

    Traditional, heavy-frame clothes racks are much sturdier. You can get these used at a garage sale or flea market for very cheap. Because they can handle far more weight, these clothes racks are more practical for larger families. The only drawback is that they take up a lot of space.

    4. A rotary dryer

  4. Improvise. When you only have a few clothes that need to be washed, you can hang-dry them on chairs, nails in the wall, closet poles, or even staircase rails. Let your imagination run wild.

    5. Hang-drying your laundry is cheap, simple, minimalist, and low-impact. Why would anyone ever use a drier again?

    1. Mr. Electricity estimates a sample load of laundry to cost 49¢ using electric power and 31¢ using gas. If the average household does 7.5 loads of laundry each week, that comes out to 49¢ × 7.5loads/week × 52 weeks/yr = $191 for electric and 31¢ × 7.5loads/week × 52 weeks/yr = $120 for gas.
    2. Photo credits: Mike Lacon, CC BY-SA. greenlagirl, CC BY-NC-SA. ario_, CC BY-NC-SA. Noel Zia Lee, CC BY. Sarah Mae, CC BY-NC. Melissa Sanders, CC BY.

Save Money On Electricity

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A typical American household might spend $100 this month on electricity. Over the course of the year, that bill will total $1200. Not only is our hard-earned money disappearing into thin air, but we are also destroying the environment in the process. That’s because to produce electricity, power plants must burn coal. Not only does this contribute to carbon emissions and smog, but forests are often destroyed in the coal mining process. The great tragedy, ultimately, is that saving electricity — and our money — is actually very simple. It only takes a few minutes to learn how to conserve electricity, but afterwards, you could save around a thousand dollars each year. That’s not a bad reward for helping to preserve the environment.

Many homeowners won’t bother with conservation simply because they don’t understand how electricity is being billed. Electricity isn’t tangible like gasoline is, so it’s difficult to figure out how electricity is measured, how much our devices use, and how all this is priced. As a result, it’s difficult to predict whether one electrical device is more wasteful than another. For example, most people know that a Hummer wastes more gasoline than a compact car, but few know whether a hair drier is more wasteful than a television. The mystery behind electricity pricing is what makes conservation difficult to practice, so before we start saving money, let’s first understand how electricity is billed.

Power, energy, and time are three related variables that follow this equation:

Energy = Power × Time

To better visualize these concepts, let’s use a rough analogy. Imagine we decide to build an old-fashioned water mill on a fast-flowing river to grind flour. The rate at which water flows influences how quickly the watermill works: the faster the river, the more flour we can grind. In a way, the rate of flow is similar to the power usage of a device: the more power your air conditioner uses, the more energy you will be charged for. Although we might measure water flow in units of feet per second, we measure electrical power in units of watts (W).

Power, however, is not what you are billed for (1). If a farmer rented a watermill to grind flour, he would probably be charged based on the amount of flour he grinds, not on the speed of the river. The amount of flour produced depends not only on the rate of water flow but also on the length of time spent milling. Likewise, our utility company doesn’t bill us for the power used but rather the total energy used. According to the equation above, the total energy is a product of power and time. Since the unit of power is in watts (W), and the unit of time is measured in hours (h), it would make sense to measure energy in units of watt•hours (W•h).

A single watt•hour, however, is a trivially small amount of energy. It’s the amount of energy that a one-watt device uses in one hour (1W × 1h = 1W•h), or what a two-watt device would use in half an hour (2W × 0.5h = 1W•h). For comparison, a single alkaline AAA battery contains around 1.15W•h (2). Measuring energy in watt•hours only makes sense for a tiny sliver of ultra-efficient devices, such LED flashlights. For the typical home appliance, however, it makes far more sense to price electrical energy in the much larger units of kilowatt•hours (1 kW•h = 1000W•h).

For our calculations, we’ll use the sample rate of $0.14/kW•h, which is the price of Tier 2 electricity from Southern California Edison as of June 2011 (3). (You’ll need to check your own electric bill to find out your exact rates.) Using this knowledge, let’s try to figure out how much it costs to operate some typical appliances:

  1. How much does electricity cost to run my laptop? I use my 2007, 13″ Macbook for about 4 hours/day, 5 days/week. During normal operation (light web surfing), it uses around 25W of power (4). 25Watts × 1kW/1000W × 4 h/day × $0.14/kW•h = $0.014/day. That is, I would pay around one and a half pennies each day to power my laptop. To figure out the cost per month, we multiply by the number of days per week, then by the number of weeks per month: $0.014/day × 5days/week × 4.5weeks/month = $0.315/month, or about 32¢ each month. To calculate the cost per year, we multiply by the number of months per year: $0.315 × 12 months = $3.78/yr, or almost four dollars each year.

    As you can see, laptops are actually cheap to power. In general, electronics designed to run on batteries are energy-efficient. (Just remember to turn them off or sleep them when not in use.) If you’re looking to save significant money, you’ll need to hunt around the house for big energy hogs. Let’s take a look at a more interesting example: central air conditioning.

  2. How much does electricity cost to run the AC during the summer? Let’s say we live in sunny Arizona, so that the AC is blasting 12 hours a day, everyday for 6 months of the year. We’ll estimate the power use of a 2.5-ton central AC at around 3500W during operation (5). One detail to remember for ACs is that they don’t usually run continuously. Air conditioners only operate when the room temperature exceeds what is set on the thermostat; all other times, the AC is in sleep mode. With this in mind, let’s estimate that the AC is powered on around 33% of the time. With the AC turned on 12 hours each day, we estimate that it is actually operating for about 4 hours each day. 3500W × 1kW/1000W × 4h/day × $0.14/kW•h = $1.96/day. The cost of operating monthly is $1.96/day × 30.5days/month = $59.78/month. The cost of operating it each year is $59.78/month × 6months/year = $358.68.

    With central AC, you would waste over $350 dollars each year. Part of the reason it’s so expensive is because central AC is cooling the entire house, when really all you need is to cool a single room. Air conditioning is also much more energy-intensive than using a fan.

  3. How much money would you save by using a fan in place of the AC? On the medium setting, a box fan might use around 60W power (6). 60W × 1kW/1000W × 12hours/day × $0.14/kW•h = $0.1008/day. The cost of operating monthly is $0.1008/day × 30.5days/month = $3.0744/month. The cost of operating it each year is $3.0744/month × 6months/year = $36.8928/year. Compared to the central AC ($358), that’s a savings of $321, or nearly 90%!

    As you can see, it pays to focus on the biggest energy-guzzlers first. Heating and cooling account for over 70% (7). The runners-up are probably lighting and refrigeration.

Monthly Cost = Power (in W) × 1kW / 1000W × h/day × Price (in $)/kW•h × days/month

Save 100% compare to the clothes dryer

Keep in mind five key tactics:

  1. Small is beautiful. All other things equal, a smaller device uses less power than a larger one. Central heating wastes much more energy than a portable space heater, and a widescreen-TV uses much more electricity than a smartphone. Save money by using the smallest appliance possible.

  2. Less is more. The less you use a device, the more money you save. Remember that saving electricity is not simply about lowering power consumption but also about lowering time used. Even Energy-Star appliances, if you leave them on all day, can waste money. So turn off devices when you’re not using them, paying special attention computers, monitors, televisions, lights, fans, air conditioners, and heaters.

  3. Not too hot, not too cold. The higher the setting on a device, the more power it uses. Turn the power on your device to the lowest setting to save plenty of cash. You can lower the power settings on most devices, such as hair driers, fans, desk lamps, and even kitchen ovens. This will make a huge difference in your heating and cooling bill. In the summer, keep your AC’s thermostat set above 80F, and in the winter, set your heater’s thermostat to lower than 60F. You could easily save hundreds each year (see above calculation).

  4. High-tech is nice. Check out compact fluorescent lightbulbs, energy-star appliances, better home insulation, front-loading washers, geothermal heating/cooling pumps, tankless water heaters, and top-opening refrigerators. Although these inventions all require an upfront cost, they will more than pay for themselves after a few years, if not a few months.

  5. But low-tech is even better. You’ll save the most money when you ditch electrical devices altogether. For example, I don’t use an air conditioner, fan, TV, smartphone, drying machine, or treadmill. Low-tech does more than save money on electricity; it saves on the upfront costs of buying equipment in the first place. If you’re serious about going green, low-tech is usually lightest on the environment.

Just like with gasoline, electricity prices will surely increase in the future. But if you lower electricity consumption today, you might be able to power your home using only renewable energy. This can help you lock in the cost of electricity, saving you plenty of money and lowering your carbon impact. Conservation, as always, is the key to financial and environmental sustainability.

  1. Usually you will be billed for energy alone, but a few utility companies have a demand charge based on your peak power usage. To illustrate, suppose you had three appliances: a washing machine, a microwave, and a vacuum cleaner. If you ran all three appliances at once, you would have a much higher peak use of power compared to if you ran one appliance after the other. The demand charge is based on the maximum power used at any instant for a given day (or month).
  2. Some batteries and the amount of energy they store.
  3. See Southern California Edison’s website.
  4. Two different estimates on Macbook power usage. I just approximated.
  5. Estimate provided by Mr. Electricity.
  6. Power data for different fans from SaveGreenly.com.
  7. According to the EIA, space heating accounts for 41% of energy consumption while water heating and air conditioning account for another 20% and 8%, respectively.
  8. Photo credits: Brian Talbot, CC BY-NC. alessandraelle, CC BY-SA.

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.