Archiv für April 2007

Cutting Carbon V

April 30, 2007 - Markus Hoenicka
Call me stupid, but last week I went to my utility company and asked them to charge more for my electricity. The reason is not a terminal loss of common sense, but I wanted to switch to a tariff that is based solely on renewable energy sources. The default tariff that I had paid for so far uses an energy mix consisting of 34% nuclear power (this alone was a reason to switch), 45% fossil fuels (mainly coal and gas), and only 21% renewable sources like water, wind, or solar energy. The new tariff, which takes effect on May 1st, uses 100% renewable sources throughout. I've calculated that I'll have to pay an extra EUR 2.50 (approx. USD 3.00) each month for this extra peace of mind. Think about that. The equivalent of one glass of beer a month.

Of course, switching the tariff doesn't make my radio blast louder or change the light from my light bulbs. Also, it's not like all "good" electrons arrive in my household and the "bad" ones in my neighbor's. Most utilities don't run all power plants themselves, but they purchase some or all electric power as needed from companies running such plants. Now that I pay more for the same amount of electrical power, the company is obliged to purchase more power from a supplier that runs on renewable energy sources only. Last year's bill shows that I consume approx. 740kWh of electrical power per year (before I started to cut my carbon dioxide emissions). Switching the tariff thus avoids 0.37 gram (0.013oz) of radioactive waste (there is no secure storage facility in Germany, so each milligram is one too much) as well as 169.5 kg (374lb) of carbon dioxide emissions per year. In other words, 18 Euro-Cent (approx. 23 US-Cent) keep 1 kg of carbon dioxide from entering the atmosphere.

Cutting Carbon IV

April 20, 2007 - Markus Hoenicka
Barely 100 years ago, ice was cut from glaciers to be sold in cities like Munich. The affluent were thus able to cool food (or beer!) during summer. The ice was put into sort of a closet, and the old-fashioned German word "Eisschrank" (ice cabinet) for fridge nicely describes the original mode of operation.

We're better off these days. Everyone has a fridge at home. Just plug it in and off you go. As fridges need to remain cool all time, they consume a considerable amount of energy, which gives me another chance to cut down on my carbon dioxide emissions.

I had a small fridge with a freezing compartment in my kitchen which was left over when my parents remodelled their home years ago. I just recently learned that this unit must be approximately 30 years old. It was still running, but not very efficiently. During summer you'd notice a stream of hot air coming from the heat exchanger, and it was running almost continuously in hot weather. I went shopping for a new, energy-efficient unit and purchased a comparable unit. According to the specs this one uses 172kWh per year. Cheaper units of the same size use up to 250kWh per year.

My old unit was probably a little worse than that when it was new. Let's assume that it used 350kWh per year because it was worn out after 30 years. Replacing the unit will thus reduce my energy consumption by approximately 180kWh per year. This amounts to saving EUR 29.00 (USD 37.00) per year. Buying the new unit will thus pay off within 8 years. Using my current tariff, I'll prevent 41 kg of carbon dioxide emissions as well as 90 mg of radioactive waste each year. Needless to say, the new fridge looks better and is a lot cleaner (duh!).

Cutting Carbon III

April 19, 2007 - Markus Hoenicka
Today I finished testing a new appliance at home. I like to start the evening with a cup of espresso or cappuccino. I'm using one of these stove-top pressure brewers that are one of the most ingenious inventions from Italy. Unfortunately, the diameter of that espresso maker is approx. 8cm (3in), whereas my smallest hot plate measures 15 cm (almost 6in) in diameter. If you compare the footprint of the espresso maker (50 sq cm) with the hot plate surface area (177 sq cm) it is easy to see that two thirds of my hot plate heat the room instead of the espresso. About time to do something.

I managed to locate a tiny hot plate with a diameter of barely 10cm. Needless to say, the hot plate is made in Italy. I've been told that many stoves in Italy indeed have such a small hot plate built in just to brew coffee. In any case, I tried whether the small hot plate was up to the task and if using this thing translates into energy savings.

First I prepared a cup of cappuccino the traditional way. The 1500W hot plate heats the water to the boil in 4 min. As the plate is large enough to heat up some milk (which is then whipped with a small battery-operated gadget) at the same time, this is all it takes in terms of electricity.

Next I used the small hot plate. It takes 6 min to brew the coffee with this 450W device. As the plate remains hot for quite a while, it is not a problem to remove the coffeemaker and use the remaining heat to warm the milk after unplugging the plate (the thingy is so simple it doesn't even have a switch).

Now let's do the math. The traditional way uses 1500W x 0.067h = 100Wh. The new plate uses 450W x 0.1h = 45Wh. That is, using the small plate saves more than 50% of energy. Lets assume I drink 250 cups of cappuccino a year. The savings amount to 250 x 55Wh = 13.8kWh a year. Using my current eletricity tariff (more about this in a later post), this translates into 3.15 kg of carbon dioxide and 7 mg of radioactive waste that I can save each year by simply using a different hot plate. The coffee tastes all the same, as far as I can tell.

Cutting Carbon II

April 17, 2007 - Markus Hoenicka
Yesterday I checked all my sockets again. I usually take care not to leave appliances in standby mode. The cheaper the appliance, the higher the risk it burns several watt 24h a day just in order to receive a wake-up call from a remote control once per day. I use power strips with switches to conveniently turn on my stereo or my computer equipment. It is really not that hard to walk up to the equipment once a day instead of pressing a button on the remote control (besides, my amplifier was built before Joe Sixpack could afford remote controls). However, scrutiny revealed that I had plugged in the transformer of a desk lamp into a power strip that was not switched off by the main computer equipment strip. As transformers consume some energy even if the secondary circuit (the lamp in this case) is switched off, I was accidentally burning a few watt for nothing. The same happened with a small transistor radio. To avoid using rechargeable batteries I used a small ac/dc power supply, but this was also directly plugged into a socket.

Now I can switch off the transformers of both the lamp and the radio. I doubt that I'll see an influence on my bills, but doing it this way certainly doesn't hurt. There's nothing like this warm fuzzy feeling of cutting your carbon emissions...especially if it boils down to using the proper socket.

Cutting Carbon

April 13, 2007 - Markus Hoenicka
Carbon isn't a bad thing at all. As a matter of fact, you can't live without it, as almost any kind of food contains carbon galore. Animals exhale carbon dioxide, but at the same rate plants fix carbon dioxide and use it as a building block to increase their biomass. Without a healthy dose of carbon dioxide and other greenhouse gases our planet would be a cold, unpleasant place that would not be able to sustain the life that we know: the energy-rich short wavelength rays of the sun pass the atmosphere almost unhindered, but the resulting longer wavelength radiation emitted by the earth's surface is partly absorbed by the atmosphere, causing it to warm up.

However, too much of a good thing isn't good either. Currently mankind releases more carbon dioxide than plants are able to capture, causing the greenhouse effect to become more efficient than necessary. In addition, other carbon-containing gases like methane (cattle burps and farts are a major source) worsen the situation. Most of us agree that something has to happen, except maybe a few nations that see pollution as an unalienable right.

I'm not going to dream up an elaborate plan that is going to save the earth. Instead, I'd like to share a few thoughts how everyone can help to reduce carbon dioxide emissions without sacrificing their lifestyle. I personally believe that it does not make any sense to wait for a bunch of diplomats to agree on large-scale plans which are inevitably overturned by reality. Instead, I prefer to do whatever I can do now, no matter how small the contribution is.

Today's installment provides a calculation of the amount of carbon dioxide which I don't release by riding a bike to go to work instead of using my car. We have about three months of sub-freezing or near-freezing temperatures over here. We have lots of rain during spring and autumn. My workplace is on top of a hill, approx. 100 vertical meters (300 ft) higher than where I live. There's 4 kilometers (approx. 2.5 miles) to go from home to work. Lots of excuses to not use a bike, but I still do. My car isn't exactly a gas guzzler, but it still releases 273 gram of carbon dioxide per 100 kilometers in the city (187 gram average). There are an estimated 240 workdays per year, equivalent to (4+4)*240=1920 kilometers (1200 miles) per year. That is, riding my bike prevents roughly 525 kilogram (1160 lb) of carbon dioxide, the mass of half a car, from entering the atmosphere each year. Besides, it is a nice workout and an effective way to make your brain wake up in the morning.