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--- efficiency_now:the_big_picture [2022/08/01 16:44] – [Energy service: Transport] wfeist
+++ efficiency_now:the_big_picture [2023/01/24 18:24] (current) – [Energy service: Transport] wfeist
@@ Line 64: / Line 64: @@
 |<WRAP box 10cm>How relevant actually is space heating? The adjacent pie chart shows that the two energy services "transportation" and "space heating" each account for around 30% of the total final energy consumption. These are thus the most significant single energy applications. From the way in which we improve the efficiency of these uses, we can learn something for the other energy services as well, and the following slides will also illustrate this. The third largest chunk "process heat" is in fact a mishmash of completely different applications, from ore smelting to candle-making; experts for process technology can develop concepts for improving the efficiency of each of these processes - which in many cases has also been successful. The solutions are available, but to a huge part not used.</WRAP>|{{:picopen:26_germany_energy_consumption_kwh_per_capita_and_year.png?&650|}}\\ <sub>**Figure 26 **</sub>|
 =====Energy service: Transport=====
-|<WRAP box 10cm>Transportation is the other major reason for our high final energy demand; this energy consumption is largely due to motorised private transport, i.e. cars and motorcycles. A measure for the energy service has been in place in Europe for decades: the annual mileage of vehicles. In 2010 this was 905 billion kilometres for cars (=sES) (energy service) in total in Germany, 718 billion kWh of petrol/gasoline were consumed as the "input" for this purpose. For a distance of 100 km these vehicles therefore had a specific energy consumption of
+|<WRAP box 10cm>Transportation is the other major reason for our high final energy demand; this energy consumption is largely due to motorised private transport, i.e. cars and motorcycles. A measure for the energy service has been in place in Europe for decades: the annual mileage of vehicles. In 2010 this was 905 billion kilometres for cars (= //s<sub>ES</sub>//) (energy service) in total in Germany, 718 billion kWh of petrol/gasoline were consumed as the "input" for this purpose. For a distance of 100 km these vehicles therefore had a specific energy consumption of
-\\ \\** $ e_{spez} = \frac {E_{sprit}}{s_{EDL}} = 80 \frac {kWh}{100 km} $ **\\ \\
+\\ ** $ e_{spez} = \frac {E_{sprit}}{s_{EDL}} = 80 \frac {kWh}{100 km} $ ** \\ \\
 (Incidentally this equates to almost exactly 8 litres per 100 km; this value has hardly changed over the decades((Although the technical efficiency of the motors has increased considerably in these periods. In this area the industry has applied improved efficiency almost exclusively for further increasing the engine power, vehicle weight and the final speed. This is often called the "rebound effect". In the present case the reason is different: The main goal of the industry had been to promote cars that are more powerful, faster and heavier. We do not wish to discuss the reasonableness of such objectives here, but we do concede that this debate is necessary. But: without the improved efficiency the energy consumption would be even much higher than it is right now; this was actually planned for: All the energy prognosis of the eighties had growing ‘demand’ as a result and the fossil fuel industry did not enjoy, that in Europe (and also in America) that growth has been reduced and even reversed.)) ). We will use this as a reference value here for further analysis.
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 Racing professionals normally manage to reach speeds around 40 km/h on average with more like 350 W for a longer period of time. This is mechanical energy of around 0.9 kWh/(100 km) and matches the energy efficiency values of bicycles ((Note about the above-mentioned 2.4 kWh/(100 km): The value of 0.9 is solely the mechanical energy which a human can 'generate' with his muscles with an efficiency of ca. 30%. The "bread roll input" in our case is 0.9 kWh/30% = 3 kWh, only a little higher than the average value in Slide 20. The normal cyclist "only" travels at a comfortable 20 km/h. By the way: approximately 0.6 kWh must actually still be deducted for the human basic metabolic rate (output necessary in any case) in both cases.)) .
-|<WRAP box 10cm> And we can be even more efficient than with bicycles. As demonstrated by this car of the University of Bochum participating in a Solar Competition: a three-seater, quite fast with a speed of **100 km/h** based on bicycle technology is even more efficient ((Because it is streamlined and has brake energy recovery.)) . Such vehicles have a consumption of just a tenth of that of an average electric car today. Prototypes that have already been realised in practice show that there does not seem to be any lower limit (>0) for the reduction of energy losses in transportation. Now it’s time to look at this from the point of view of basic physics.</WRAP>|{{:picopen:32sun_cruiser_no_it_is_not_mainly_a_question_of_velocity..._but_of_technology.png?&650|}}\\ **Figure 32 **|\\
+|<WRAP box 10cm> And we can be even more efficient than with bicycles. As demonstrated by this car of the University of Bochum participating in a Solar Competition: a three-seater, quite fast with a speed of **100 km/h** based on bicycle technology is even more efficient ((Because it is streamlined and has brake energy recovery.)) . Such vehicles have a consumption of just a tenth of that of an average electric car today. Prototypes that have already been realised in practice show that there does not seem to be any lower limit (>0) for the reduction of energy losses in transportation. Now it’s time to look at this from the point of view of basic physics.</WRAP>|{{:picopen:32sun_cruiser_no_it_is_not_mainly_a_question_of_velocity..._but_of_technology.png?&650|}}\\ **Figure 32 **|\\ \\
+===== Moving fast? =====
 What does physics say about this? We have already learnt about the definition of the energy service in transportation (person-km or cargo-km).
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 Also for lighting, the improvement in efficiency was the most important parameter for achieving the currently customary level of comfort. It is still worthwhile to apply approaches in which light is used in a targeted way in the places where it is actually needed - and switch it off where it does not provide a benefit. However, with the level of efficiency available today, the provision of sufficient light at all times completely on the basis of renewable energy sources is possible, the couple of hours of electricity storage necessary for this is also easily available for such a small consumption.</sub>|\\
-=====Rebound-Effect?=====
+===== Rebound effect? =====
 In this example one can also discuss the question, what role the so called “rebound effect” can play. In order to “consume” the savings made possible by the improved light source, we would have to increase the luminous flux by a factor of 17. Of course, that is possible – but it’s actually not done in practice. Yes, there has been some improvement in illumination, it may even be by a factor 3. But that would still leave us energy savings of >83% instead of the possible 94%. Obviously, this does not matter very much – both savings are extremely high and both are high enough to be able to provide the energy needed solely by renewable generation.  In order to “fight” rebound effects, the improvement in efficiency has just to be high enough, so that the remaining “demand” will be negligible anyhow. As is the case for passive houses, bicycle-technology based electric light weight vevicles and LED-light. For the specific case of passive houses that is discussed in more detail in [[efficiency_now:the_big_picture#Literature|[Johnston 2021] ]] \\
+This article will show how this is possible in many ways: Passive House buildings require such a small amount of heating energy that the remaining demand is no longer difficult to meet, lightweight electric vehicles based on bicycle technology can be supplied with power from solar panels on the roof of the house, and LED lights only have an extremely small electricity demand.
+Moreover, there is no reason why we shouldn't think also about the meaning and purpose of further increased utilisation of energy services. Does the fact that today we can fly to holiday destinations in increasingly far-off regions three times a year instead of just once a year really improve the quality of our lives? Is a room temperature of 23°C in winter, implicitly agreed on for light clothing, really benefit us 57)? Do we really have to buy new lounge furniture every 8 years? Is our awareness of life really so much better at a speed of 180 than at 130? I know from experience with numerous discussions that these questions are capable of triggering huge emotional reactions, and on both sides by the way, each of which represents a resolute position. I think that it is especially important to reflect on this; in view of the urgent risks of the climate crisis and the time remaining to us for finding a solution, there are certainly important arguments in favour of reflecting on this.
+The situation is different for efficiency potentials: these can in fact be implemented without having a debate on the virtues of abstinence; in many cases, there may even be an increase in the energy service, with the savings remaining high despite this. Everyone can benefit from exploiting these efficiency potentials, regardless of their position on these questions. ||
+|<WRAP box 8cm> As an amateur astronomer, I would like to touch on a related subject: light pollution, which is increasing worldwide. We have become so used to the availability of cheap light all day long that in some places everything is lighted up even all throughout the night, with the consequence that often we can no longer see the stars in the sky, let alone the subtle band of the Milky Way - a real cultural deficit, robbing us of the connection to our cosmic home. Astronomic observations are increasingly becoming difficult.\\ \\
+With growing material prosperity, more and more people can now afford to consume more of previously scarce goods. In my view this undoubtedly constitutes progress in overcoming hunger, disease, homelessness and shameless exploitation - that must be kept in mind by those who seek a solution exclusively in abstinence. However, if I already have 500 lux available to me on my desk then the next 500 by far will no longer be such an enormous increase in the quality of life. If I demand that such amounts of light at least should not be emitted into the night sky through the windows is a legitimate demand for the quality of life of my fellow human beings, particularly that of astronomers.\\ \\
+**Conclusion:** even though a good level of lighting is very cheap, attention should still be given to less light leakage into the surroundings. </WRAP>  | {{ :picopen:milkyway2.jpg?650 }} \\ <sub> // Milky Way observed from northern latitudes. This is our cosmic home - each of these bands consists of several hundreds of millions of stars. //  Picture: Fresh.waffles CC BY-SA 4.0.  </sub>|
 ===== Energy service: communication, information technology =====