Energy Cannot be Created or Destroyed

There’s been a lot of focus of late on two areas of the climate debate: reducing household energy consumption and increasing generation from renewable sources. This is only half the battle, though, because a vast proportion of the energy we use is actually in the manufacture and transport of our stuff. Recent PhD work at the Norwegian University of Science and Technology has shown that 60 – 80% of environmental impacts are from household consumption of things rather than from running lights, A/C, cooking etc.

That’s staggering, but is it surprising? I look in my top draw at home and it’s full of pens I’ve never used and never think about. Each pen required energy in every stage of its genesis: Oil drilling and refining in to plastic and ink, metal mining and refining, manufacturing, transport, and marketing. Our old friend Galileo taught us about the law of conservation of energy – energy cannot be created or destroyed, it just changes forms. For our pen the energy form changes are complex and none of them can be recovered. I remember sitting in the back of my dad’s car as a young fella and asking him how a car worked. I was astonished to learn that once the gases left the tailpipe, that was it. There was no energy recovery. Fuel in, gas out. An open cycle! Galileo would not be happy.

One day I’m going to clean out my top draw and all the embodied energy in those pens will be wasted when they go to landfill (or hopefully in the recycling bin). The aforementioned supply chain is for a simple pen. Imagine what goes in to a new car or dishwasher. Most of the emissions released by creating our stuff is out of sight, out of mind because they are left in China or some other manufacturing hub where the people and environment there suffer with the consequences of the pollution.

Let’s take a closer look at my dad’s car. It was a 1982 Toyota Camry GLi. It had a 2 litre engine and was fuel injected. She was a sexy beast.

Dad’s 1982 Toyota Camry GLi, AKA “The Limousine” (source)

My Dad liked Camrys and actually upgraded to a new (used) Camry every 8 or so years, pretty close to the Australian average of 10 years. With the Camry being one of the most popular cars in Australia and one of the leaders of the medium car market for many years, it’s a good case study. Below is the fuel economy and emissions from Camry models since my Dad’s first Camry.

Toyota Camry Economy and Emissions (1982 – Present)* source

So apart from an increase in emissions and decrease in economy in the early ’90s (likely due to the extra weight of modern safety equipment required by design codes), the Camry has maintained or improved its efficiency and emissions in the last 35 years.

Now, based on the average age at which Australians turn over their cars and the embodied energy in each car the difference between buying a 1982 Toyota Camry, maintaining it and running it for 35 years vs buying a new car every 10 years is staggering. Taking the new car option results in a 38% increase in emissions for the same amount of driving!** This is because manufacturing and shipping a new Camry releases over 10 tonnes of CO2 equivalent in to the atmosphere which is about a third of the total lifecycle emissions of the car (manufacturing, shipping and running). And whilst cars have gotten more efficient and cleaner over time, it’s not by a huge amount.

This is, of course, purely a thought experiment since there are many good reasons to buy a new car including improved safety and reliability credentials. The impact of improved emissions on respiratory health in cities is important so I am certainly not proposing everyone drive old cars. But this example illustrates the point that the embodied energy, and the emissions involved in creating our stuff is significant and worthy of further thought. It also gives you ammunition for hoity toity Prius owners next time they profess to be saving the planet.


*Calculated using mixed highway/city kms from real-world experiments, not manufacturer documentation.

**Based on ABS quoted data (2014) for average Australian kms driven. For detailed calculations please email me and I’ll happily send you a copy.

3 thoughts on “Energy Cannot be Created or Destroyed

  1. Pingback: Grub – JIUNTU

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