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Siemens Stiftung

How long will our energy sources last?

Chart:
A bar chart shows an overview of the remaining years of use of primary energy sources.

Of the fossil energy sources, petroleum will be the first to run out. What is the situation for the other fossil energy sources? Can new technologies delay the point in time when they run out? And is it really true that renewable energy sources never run out?
The time axis has a logarithmic scale.

Information and ideas:
Students learn that the logarithmic scale represents numbers ranging over several powers. More in-depth information regarding how long energy sources will last is provided in the "An overview of energy sources? information sheet.


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Siemens Stiftung

Global energy supply - future development

Chart:
The development of the global energy supply from 1990 to 2035 is shown.

Reliable figures are available through 2012; from that date forward, the International Energy Agency must rely on estimates. The represented figures refer to the more optimistic New Policies Scenario, which takes into account political announcements and plans of governments, for example, to reduce CO2 emissions, although they have not yet been implemented. The estimated energy consumption for 2035 is 12,001 mtoe.

Using the following source: International Energy Agency (IEA)


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Siemens Stiftung

Food production - "energy hog?

Interactive graphic:
Production stages for a food until it is eaten, with the energy consumption and energy-saving potential for each stage.

An industrially produced foodstuff generally has to travel a long way before it lands on our plate. This is illustrated graphically using an example of a food (chicken wings). At each step, the graphic shows what energy is needed for and what measures could be taken to save energy. Synthetic amino acids are named as one energy-saving possibility. All essential amino acids (for example, methionine) can be produced synthetically today and would save up to 95 percent of the energy if used in feed, compared, for example, with growing soy beans. In addition, the use of freshwater and pollution with fertilizers and pesticides would be reduced. Further potential for saving energy can be discussed.

Information and ideas:
Because this media file shows energy consumption in the context of food production and consumption, monitoring one?s own consumption would be appropriate. Students should think of meals for one day that use as little energy as possible for production, transportation, consumption, and waste disposal. The thoughts can range from mostly unprocessed products to completely synthetic products.
The "Meat and sustainability? animated film is suitable to get the students thinking.


Dieses Material ist Teil einer Sammlung

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Siemens Stiftung

Phase diagram of water

Diagram:
A P-T diagram for pure water. The lines indicate the temperature and the pressure at which the solid, liquid, and vapor phases exist in equilibrium. All three phases exist in equilibrium only at the triple point; otherwise, there are a maximum of two phases.

In addition to the equilibrium curves (melting pressure curve, sublimation curve, vapor pressure curve), the diagram also includes the pressure and temperature data for the melting, boiling, triple, and critical points.
Attention: The axes of the diagram are not shown true to scale.

Information and ideas:
This diagram also reflects the density anomaly of water (lower density in the solid state than in the liquid state): The melting pressure curve shows a negative slope. The reason for the density anomaly is the hydrogen bonds.

Anderer Ressourcentyp

Siemens Stiftung

Phase diagram of water

Interactive diagram labeling:
A p-T diagram for pure water. The lines indicate the temperature and the pressure at which the solid, liquid, and vapor phases exist in equilibrium. All three phases exist in equilibrium only at the triple point; otherwise, there are a maximum of two phases.

The diagram can be labeled interactively, either individually or in full. Manual labeling on the interactive whiteboard is also possible.

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Siemens Stiftung

Excitation energy of a water molecule

Chart:
Water can absorb heat energy in the form of vibrations or movement of its molecules. This energy content depends on the physical state: steam contains more energy than liquid water, for example.

The material surrounding us takes on different physical states depending on pressure and temperature (in Kelvin): solid, liquid or gaseous. This also applies to water: During a phase change from solid to liquid and liquid to gas respectively the energy of the water molecules increases without the temperature rising - the diagram for water shows plateaus. The values of these plateaus are approx. 6 kJ/mol (melting heat) and approx. 40,7 kJ/mol (vaporization heat) respectively.

Information and ideas:
Ideally suited for explaining the topic of phase equilibrium.

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Siemens Stiftung

Steam pressure curve and phase diagram of water

Charts:
The steam pressure curves (p-V diagram) and the phase diagram (p-T diagram) of water are compared.

If you heat water to 100 °C at normal atmospheric pressure, it turns into steam. But what effect does raising or lowering the pressure have on the vaporization temperature?
The answer to this is given by the steam pressure curve (T-curves in the p-V diagram on the left) and the phase diagram (p-T diagram of the right) of the water. Steam pressure is the term for the pressure at which gas and liquid are in equilibrium, i.e. the same number of molecules evaporate as condense back into water. Above the critical temperature (numerical values are given) the water is always gaseous, regardless at what temperature, and it can be treated as a real gas (Van der Waals equation, formula is given). At every temperature below the critical temperature there is a steam pressure for which there is a two-phase zone (liquid and gaseous). In the liquid phase range it is possible to recognize from the steep rise in the curves that liquid substances are barely compressible.
The critical temperature must not be confused with the triple point temperature (see p-T diagram). This characterizes the values of temperature and pressure at which all phases (solid, liquid and gaseous) are present simultaneously.

Information and ideas:
At what temperature does water boil on Mount Everest? So-called "Steam pressure tables" provide information about this. It would also be interesting to refer to the phase transition points as temperature critical points. At the phase transition from liquid to gaseous the energy applied does not initially lead to an increase in temperature. The same applies to the melting of ice. Not until all the water has evaporated or melted does the temperature rise further.

Anderer Ressourcentyp

Siemens Stiftung

Link list for "The tropical rainforest" interactive whiteboard content

Link list:
Additional links on the topic of rainforests.


Additional information on the topic of "rainforests" for class (e.g., WebQuests, images, informational texts, games) or as background information for teachers.

Anderer Ressourcentyp

Siemens Stiftung

Link list for the media package "Humanitarian aid - drinking water filters in use"

Link list:
Many interesting links on the topics of "Drinking water shortage", "Humanitarian aid", and "Membrane filters".


Information and ideas:
Equally suitable as a source for Internet inquiry for teachers and students alike.

Video

Siemens Stiftung

Meat and Sustainability

Video:
Animated film that clearly shows the impact of high meat consumption in Germany

On average, each German eats nearly 90 kilograms of meat per year. That is excessive and problematic in many ways. Industrial production of meat is unsustainable in many aspects - area of land use, global food supply, climate change, animal rights, pollution, and health.

What problems are specifically caused by industrial meat production? What are the global consequences? What can be done about it?


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