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--- efficiency_now:the_big_picture [2022/08/02 09:52] – [Rebound-Effect?] yaling.hsiao@passiv.de
+++ 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).