2008-01-20
An Inconvenient Truth
After my previous posting on energy I searched for some more figures on energy consumption. I wanted to get a rough idea of the energy consumption of families (in The Netherlands). So I looked for the figures for energy consumption per year of gas, electricity and petrol.
An average car drives 13000 km/year. With an efficiency of 15 km/l the total usage of petrol is 866 l/year. The energy (more correct heating value) of one liter of petrol is 35 MJ, which is equal to 9.7 kWh/l. The average energy consumption of a car is thus 8400 kWh/year.
An average Dutch family uses 1600 m3 natural gas a year. The heating value of Dutch natural gas is 32 MJ/m3, which is equal to 8.9 kWh/m3. The average energy consumption on gas is thus 14200 kWh/year.
An average Dutch family uses 3300 kWh/year electricity. However, this is the net usage. Power plants have an efficiency of nearly 60%. The gross usage is thus 5500 kWh/year.
The total power consumption of those three resources is 28100 kWh/year, with a distribution of 30% petrol, 50 % gas and 20% electricity.
What do we save if we replace a 60 W electrical bulbs by an energy saving 10 W CFL? The saving is 50 W * 3 hours/day * 365 days = 55 kWh/year net, or 92 kWh/year gross. This is only 0.3% of the total energy consumption of a family! I think we're often not focusing on the right topics for energy saving.
Note, that I assume there is only 1 car per family. The current figure is already somewhere between 1.0 and 1.1 car per family. I also do not take care of the energy loss due to transport and refineries.
References:
http://www.vrom.nl/Pagina.html?id=9288
http://en.wikipedia.org/wiki/Fuel_efficiency
http://en.wikipedia.org/wiki/Heating_value
http://en.wikipedia.org/wiki/Electricity_generation
http://nl.wikipedia.org/wiki/Aardgas
An average car drives 13000 km/year. With an efficiency of 15 km/l the total usage of petrol is 866 l/year. The energy (more correct heating value) of one liter of petrol is 35 MJ, which is equal to 9.7 kWh/l. The average energy consumption of a car is thus 8400 kWh/year.
An average Dutch family uses 1600 m3 natural gas a year. The heating value of Dutch natural gas is 32 MJ/m3, which is equal to 8.9 kWh/m3. The average energy consumption on gas is thus 14200 kWh/year.
An average Dutch family uses 3300 kWh/year electricity. However, this is the net usage. Power plants have an efficiency of nearly 60%. The gross usage is thus 5500 kWh/year.
The total power consumption of those three resources is 28100 kWh/year, with a distribution of 30% petrol, 50 % gas and 20% electricity.
What do we save if we replace a 60 W electrical bulbs by an energy saving 10 W CFL? The saving is 50 W * 3 hours/day * 365 days = 55 kWh/year net, or 92 kWh/year gross. This is only 0.3% of the total energy consumption of a family! I think we're often not focusing on the right topics for energy saving.
Note, that I assume there is only 1 car per family. The current figure is already somewhere between 1.0 and 1.1 car per family. I also do not take care of the energy loss due to transport and refineries.
References:
http://www.vrom.nl/Pagina.html?id=9288
http://en.wikipedia.org/wiki/Fuel_efficiency
http://en.wikipedia.org/wiki/Heating_value
http://en.wikipedia.org/wiki/Electricity_generation
http://nl.wikipedia.org/wiki/Aardgas
2008-01-08
Polar bears or Autism
Have you ever wondered why polar bears in the zoo pace up and down? In Dutch we even use the expression ‘ijsberen’ for pacing up and down. Why do they do that? It’s just because they have to walk. It’s not a choice. It’s their default behavior. Just like many people have to talk, even when there is nothing to say.
I just read a wonderful book, ‘The curious incident of the dog in the night-time’. It’s very well written and read it cover to cover without interruption. It’s about a boy who seems to have some form of autism. It’s written from his perspective. It shows a world where emotion is mostly limited to fear, except for the happiness created by mathematics. It’s a world that has very strict logical rules. However, most rules don’t make sense to ordinary people.
I intentionally wrote ‘seems to have some form of autism’, because nowhere in the story the word autism is used. The behavior of the boy looks like autism, but his thoughts are not. His thoughts are too rational, too conscious. E.g. in the book there is a passage
The film Amadeus gives an example of such uncontrolled behavior. Mozart’s mother in law is giving him a lecture. Her fulminating words fade out and the Zauberflote fades in. The creation of the music just seems to happen to him. (I’m not saying Mozart is autistic. A guy that flirts with all the girls can’t be autistic.)
I believe that’s what happens with autistics too. They lose control and start doing something they can do well. It’s not their intention to do so. They don’t decide to do so to relax. It just happens.
Polar bears just have to walk. Doing mathematics is the default behavior of some people. I have to admit. I sometimes have the strange habit to check (large) numbers on divisibility by 9. I see a number and just want to know whether it can be divided by 9. No, I’m not really autistic. I failed the test, low AQ. I’m using a trick for the division by 9. An autistic would just know, without doing any computations.
For those interested in autism I suggest to visit the site of Eric Chen. He gives an alternative description of the Theory of Mind for autistics.
Finally, I would like to note that there is a strange mathematical mistake in The Curious Incident. In one of the mathematical pieces it says that it is not very exceptional to have 5698 times head when throwing coins. If everybody on the world would be throwing coins there will be a million people with 5698 times head. Well, that’s a big mistake! The chance to throw 5698 times head is 1 out of 2^5698 = 1.9 * 10^1715. Yes, a number with 1715 zero’s There are only 10^80 atoms in the universe! and it’s barely 4.3 * 10^17 seconds old! So, a sequence of 5698 heads is a good approximation of impossible.
I just read a wonderful book, ‘The curious incident of the dog in the night-time’. It’s very well written and read it cover to cover without interruption. It’s about a boy who seems to have some form of autism. It’s written from his perspective. It shows a world where emotion is mostly limited to fear, except for the happiness created by mathematics. It’s a world that has very strict logical rules. However, most rules don’t make sense to ordinary people.
I intentionally wrote ‘seems to have some form of autism’, because nowhere in the story the word autism is used. The behavior of the boy looks like autism, but his thoughts are not. His thoughts are too rational, too conscious. E.g. in the book there is a passage
because there were too many and my brain wasn't working properly and this frightened me so I closed my eyes again and slowly counted to 50 but without doing the cubes.Eric Chen has rewritten this passage to a more realistic autistic reaction
There are too many lines striking me. I tried to cover my eyes and scream so that these lines would go away, but they won't.People, even autistics, do not think ‘my brain wasn’t working properly’. They just start doing something ‘strange’.
I screamed more.
The world became flashes and dots of light and lines. That mades me sink into darkness and sleep.
[Quote from Autism Myths]
The film Amadeus gives an example of such uncontrolled behavior. Mozart’s mother in law is giving him a lecture. Her fulminating words fade out and the Zauberflote fades in. The creation of the music just seems to happen to him. (I’m not saying Mozart is autistic. A guy that flirts with all the girls can’t be autistic.)
I believe that’s what happens with autistics too. They lose control and start doing something they can do well. It’s not their intention to do so. They don’t decide to do so to relax. It just happens.
Polar bears just have to walk. Doing mathematics is the default behavior of some people. I have to admit. I sometimes have the strange habit to check (large) numbers on divisibility by 9. I see a number and just want to know whether it can be divided by 9. No, I’m not really autistic. I failed the test, low AQ. I’m using a trick for the division by 9. An autistic would just know, without doing any computations.
For those interested in autism I suggest to visit the site of Eric Chen. He gives an alternative description of the Theory of Mind for autistics.
Finally, I would like to note that there is a strange mathematical mistake in The Curious Incident. In one of the mathematical pieces it says that it is not very exceptional to have 5698 times head when throwing coins. If everybody on the world would be throwing coins there will be a million people with 5698 times head. Well, that’s a big mistake! The chance to throw 5698 times head is 1 out of 2^5698 = 1.9 * 10^1715. Yes, a number with 1715 zero’s There are only 10^80 atoms in the universe! and it’s barely 4.3 * 10^17 seconds old! So, a sequence of 5698 heads is a good approximation of impossible.
