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Gray energy - the secret energy thief

gray energy

A fruit salad of kiwi and banana, a Kornspitz with ham and cheese, plus a glass of orange juice. A breakfast that not only contains energy and vitamins, but also has a long journey behind it. Did you know that these ingredients of such a "long-distance breakfast" were transported in total up to 30.000 kilometers to land on your plate? The biggest globetrotters are 11.000 kilometers of Brazilian orange juice and banana Costa Rica. Followed by cocoa from Africa (6.000 km), spanish turkey (2.200 km).

Those who prefer meals with fewer miles, can take the environment a big load. The example of breakfast, this is quite simple: fruit mainly from Austria, oranges from Italy (about 1.000 kilometers) and sausages and cheese in this country in abundance. The Department of Environmental Protection of the Upper Austrian Provincial Government has calculated that such a "short-haul breakfast" has on average only one-tenth of the entrance table at the entrance.

Electricity consumption household
According to Statistics Austria, the average power consumption of an Austrian household between 2003 and 2012 has dropped by nine percent, from 5.000 to nearly 4.600 kilowatt hours. The largest decline is in 45 percent air conditioners and circulation pumps due to ever increasing efficiency, followed by standby with minus 30 percent, large appliances with minus 23 percent, space heating minus 18 percent, hot water minus 13 percent. On the other hand, electricity consumption has increased the most for lighting and small appliances by 16 percent, cooling and freezing by four percent, and cooking by three percent

Gray energy per material
Aluminum: 58 kWh / kg
Copper: 26 kWh / kg
Brick (700 kg / m3) 701 kWh / m3
Reinforced concrete: (2.400 kg / m3) 1.463 kWh / m3
Mineral wool: 387 kWh / m3
Cellulose: 65 kWh / m3
(Source: Amt der Oö. Landesregierung, Department of Environmental Protection)

Energy saving for Lazy
• Manual dishwashing needs around 50 percent more energy due to the higher domestic hot water consumption compared to dishwashers.
• Cooking with lid saves up to 30 percent. For example, if you bring 1,5 liters of water without a lid to a boil, it takes three times as much energy.
• For refrigerators and freezers: do not leave open long, replace seals, do not put hot food in, keep a sufficient distance from the wall and do not place next to radiators.

Invisible energy

Foods with long transport distances are one of many examples of gray energy. This term refers to the energy consumed in the manufacture, transport, storage and disposal of goods that is not purchased directly by the customer or generated by a device during operation. It is the indirect energy demand that is not related to household electricity or gas.
Gray energy does not appear on any consumer's electricity bill, but life is indispensable. Many products already have a large amount of energy at their disposal before we even put them into operation. As a rule of thumb, the Federal Statistical Office of Germany calculated: Per spent euro for consumer goods, caused about one kilowatt hour of gray energy.

Greedy for gray energy

A very large amount of gray energy hides in buildings. Building a house consumes about as much energy as the building consumes later in 30 to 50 years ago. The reason for the ever-increasing share of gray energy is the construction of scattered settlements, since road construction and infrastructure account for more than two-thirds of the hidden energy.
Also energy hungry is the production of a car. It uses approximately 30.000 kilowatt-hours to roughly consume the power of a family household over a period of ten years.
But also in the household lurk devices that were particularly greedy for energy during production and transport. Refrigerators and washing machines require about the same amount of energy as they consume in their production within eight years of production.

Much greater is the gap between actual energy consumption and gray energy in high-tech electronic devices. Their production already generates the multiple of energy that they consume in the course of their period of use. A computer consumes only about a seventh of the energy consumed in its production (about 1.000 kWh), a smartphone about a tenth. In other words, producing a smartphone consumes about ten times as much energy as the device consumes during its entire life.

The energy demand behind print products is scarily high. A newspaper consumes about five kilowatt hours and is about the same power consumption as five hours of vacuuming, but is read on average only half an hour a day.

The fairy tale of the "efficient refrigerator"

The following example shows that the energy efficiency class plays a subordinate role when one compares the higher price of a new device to the energy savings that are possible with it:
A freestanding fridge-freezer (around 300 liters net capacity) consumes 1.700 kWh (kilowatt hours) in class A +++ in ten years. A comparable class A ++ consumes 2.000 kWh. By comparison, a device more than ten years old (energy efficiency classes of the past are not comparable with today) eats about 2.700 kWh. The electricity costs are more than 500 Euro after ten years of operation. The class A +++ device consumes good 300 Euro in electricity. This results in a saving of just under 200 Euro on ten years. In view of the considerable additional costs (usually more than double) of an A +++ device compared to A ++, this calculation does not work out, but ranks as a fairy tale.

Gray Energy: Ways to Avoid?

Gray energy is found in almost all the tangible and intangible goods we consume, so it is almost unavoidable. The industry tries to make the consumers with the keyword "energy efficiency" when buying a clear conscience. But for a meaningful energy balance of a device to throw the consumed during the production and transport of gray energy, as well as the energy consumption during operation and life in a pot. And given the very high proportion of gray energy in many devices, the power consumption from the socket is often a negligible factor.

This is especially important when buying new electrical appliances. In many cases - especially if you do not often need them - it may be better to reuse old household appliances to save on gray energy and raw materials. The Swiss Agency for Energy Efficiency (SAFE) gives it a decision support: The replacement of a five to seven year old device is only useful if a repair costs more than 35 percent of the purchase price for a new device. At ten years it is 30 percent and from ten years you should use ten percent as a pain threshold. From a financial point of view, the purchase of new household appliances, only because of a higher energy efficiency class, brings no benefits (see info box "The fairy tale of the efficient refrigerator")

Conclusion: The linchpin for avoiding gray energy is consumption. For those who keep their products longer, industry has less need to produce new products, which in turn reduces the associated energy consumption. Only by the use of energy-saving products is one far from a great energy saver, one must change his consumption behavior fundamentally. This includes, among other things, the avoidance of disposable and disposable products.

A power plant for standby mode

An average household spends 170 kilowatt hours per year only on devices that sleep in standby mode. If you actually take them off the grid - for example, through switchable power strips - you could save as much as 34 Euro every year. All households in Austria spend about 123 millions on standby, that is 615 Gigawatt hours. Incidentally, this corresponds to the annual electricity production of the Kaunertal power plant, the storage power plant with the highest annual production in Austria.

Examples of costs in standby mode:
• Fully automatic coffee machine: three watts (makes 26 kWh annually or five euros per year)
• LCD TV: one watt (8,7 kWh or 1,7 Euro per year)
• Modem + Router: five watts (44 kWh or 8,7 Euro per year)
The examples are approximate, consumption may vary greatly depending on the manufacturer and model.

Photo / Video: Shutterstock.

Written by Stefan Tesch

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