Tag Archives: conservation

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.

Why Abortion Isn’t Green

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A friend once asked me, “Why are you an environmentalist?” In essence, he was asking me why I cared so much. Of all the issues to be passionate about in life, why the environment?

I wasn’t sure how to answer him at first. I could have replied with any one of a hundred reasons. I thought about mentioning global warming, or cancer villages, or rainforest deforestation, or even oil spills. I had so many reasons that it felt impossible to answer the question with a single sentence.

But eventually, I decided to keep it simple. I told him that I was an environmentalist because I cared about protecting people.

In the end, I wasn’t an environmentalist because I cared that much about nature in itself. Preserving the earth’s ecosystems as its own end goal isn’t worth getting passionate about — but protecting people is.

Unfortunately, many environmentalists don’t share the same motivation. In their zeal to protect our planet’s beautiful ecosystems, they have forgotten the humane motivations behind their work. Instead of protecting people, they advocate that we kill them instead — in the form of abortion — to lower our environmental footprint (1).

They think that by having more children, we will only place greater pressure on the earth’s ecosystems. If we could only limit the birth rate, there would be fewer people alive to pollute, which would lower overall greenhouse gas emissions. Any method of population control, including killing the unborn, is a noble cause for the sake of the environment.

The Bible speaks so clearly against abortion that it leaves no room for debate. Even when a fetus is still in his mother’s womb, God considers him to be a human. As it says in one poem:

For you formed my inward parts; you knitted me together in my mother’s womb. I praise you, for I am fearfully and wonderfully made. Wonderful are your works; my soul knows it very well. My frame was not hidden from you, when I was being made in secret, intricately woven in the depths of the earth. (Psalm 139:13-15)

From the moment of conception, we human beings bear the likeness of God’s image. Human life has sanctity — no one is allowed to arbitrarily take life away. As it says in the Bible: You shall not murder (Exodus 20:13). Terminating the life of another human, no matter how young or how small, regardless of the noble environmental intentions, is still murder.

The irony with abortion is that it doesn’t really solve any environmental crisis. In fact, we have many reasons to suspect that more abortions will simply increase our net environmental footprint.

The underlying root cause of environmental crises is overconsumption, not overpopulation. In the past, hundreds of millions of people inhabited planet earth without causing any of the environmental crises we face today. There were no problems with carbon emissions, landfills, e-waste, smog, or shrinking oil reserves. So clearly, these problems aren’t caused by overpopulation alone. It takes a short-sighted, modernized, Western culture to produce such catastrophes on a global scale.

A country’s population actually has very little to do with its levels of pollution. That’s because not all people pollute equally. The amount of pollution a person generates is roughly proportional to his wealth, since money represents control over natural resources. 80% of the world’s global income is controlled by the hands of 20% of the earth’s population. These wealthy 20%, located mostly in Western countries, are responsible for the vast majority of oil consumption, e-waste, and global warming. The remaining 80% of mankind survive on less than $10 each day; they are simply too poor to do much harm.

Ironically, it’s precisely those countries with low birth rates that are causing the most environmental damage. These nations tend to be wealthier and have stronger consumer cultures. Think of it like this: A single wealthy suburban American can produce more pollution than a hundred African slum-dwellers combined. The American lives in a McMansion, drives an SUV, takes cruise trips to Europe, eats fast food, and buys tablet computers. Slum-dwellers can’t really afford to do much besides buy food and water. And even when it comes down to basic essentials like water, we somehow manage to waste more per person as Americans than the rest of the world.

Fertility rate by country. Notice that the women in the Southern Hemisphere have lots of kids (3+ children per family) whereas women in the modern, Westernized nations in the Northern Hemisphere have far fewer children.


Carbon dioxide emissions per person per country. Notice that the most of our carbon emissions is coming from Western nations in the Northern Hemisphere.


Average daily water use per person by country. The average American uses around 10-30 times as much water as the average person from the Third World.

Encouraging a Westernized, child-free lifestyle, along with abortion, will probably make environmental crises worse. This is because families with children tend to pollute less per person than families without children. If a married couple has ten kids, they will be forced to spend most of their income on basic essentials like shelter, food, and clothing. Even if they wanted to pollute, they wouldn’t be able to afford to — they have too many mouths to feed. However, a married couple with dual-income and no kids will have plenty of extra cash. They’re more likely to buy sports car, SUVs, mansions with private swimming pools, round-the-world plane tickets, cruise vacations, and wide-screen TVs.

Clearly, what matters is not the absolute number of people on the planet, but our per person rate of pollution. This rate is determined by how much a society is influenced by our Western, consumer culture.

Sadly, most policymakers still think that murder by the millions is the appropriate solution. They’re even trying to export this atrocity to the developing world. Yet at the same time that we advocate abortion, we’re also advocating the American Dream.

We have seen this policy fail before. Since the 1970s, China has followed a one-child policy, which fines families for having two or more children. As expected, China’s population growth is slowing. However, its carbon footprint is growing exponentially. Within a few decades, it may even surpass the USA!

This child-free, consumer culture may also catch on in India. Yes, abortion would result in fewer people, but expect the total pollution to skyrocket. If more Indians start driving cars, eating fast food, and buying consumer electronics, pollution will rise even as the population remains stagnant.

Ultimately, there are two ways to view our planet earth:

On one hand, there are those believe that earth’s resources are scarce. Life is nothing more than an endless competition for limited natural resources like food, water, land, and oil. To survive, it is necessary to steal, attack, and kill. Unborn children aren’t human beings — they’re just competitors. So the less children we have, the greater our own share. Ultimately, this belief is either fueled by ignorance or by sheer greed.

On the other hand, there are those who believe that the earth has plenty. If society would only plan for sustainable development, there would be enough to share. Wise stewardship, not competition, would be the solution to our present environmental crises. If we only gave up consumerism, it would be possible to house, feed, and clothe all of earth’s billions of people.

There’s no false dilemma between caring for the environment and caring for humanity. They are one and the same. After all, that’s why I’m a Greenimalist — so that our future children can enjoy the earth for decades to come.

  1. Abortion is murder, plain and simple. However, most environmentalists are willing to consider it. Grist, for example, consistently advocates this atrocity. These environmentalists forget that the reason we protect the environment is to protect people, which include the unborn.
  2. Photo credits: tonrulkens, CC BY-SA. PlatypeanArchcow, public domain. Dbachmann, CC BY-SA. Date 360, United Nations Human Development Report 2006.