Organic hand-knitted tofu

“Actually,” I said to the freelance journalist, “I rather like being able to afford to drive a gas-guzzling, ozone-depleting, polar-bear-drowning four-wheel drive.”

“Would you like me to quote you on that?” he asked.

Yet to my own embarrassment I find myself drifting inexorably towards a ecology-minded existence. Not deliberately, you understand.

Agreed, the Goatmobile is a gas-guzzler. It actually burns rather less than the ol’ Disco by about 50%. Seventeen miles per gallon is a lot less unimpressive than twelve. Since buying the motorbike, my personal monthly petrol consumption has dropped from some 90 gallons to around 60 gallons. I make that a monthly saving of about 200kg CO₂ not pumped into the troposphere. Of course, I could have gone to work by bicycle, but that would have required several tins of ozone-depleting deodorant, there being nowhere to shower and change into the mild-mannered Clark Kent upon arrival at the office.

Just for the interest of any chemist who might accidentally have stumbled upon this blog, and to prove to myself that all that O-level Chemistry hasn’t been entirely forgotten…

Petrol is typically a mixture of C₅H₁₂ to C₁₂H₂₆

Atomic weights: H=1, O=8, C=12

Lightest fraction: C₅H₁₂ + 8O₂ = 5CO₂ + 6H₂O

5x12 + 12x1 + 8x16 = 5x(12+16) + 6x(2+8) = 200
72 + 128 = 140 + 60

72g petrol produces 140g CO₂

Heaviest fraction: 2C₁₂H₂₆ + 37O₂ = 24CO₂+ 26H₂O
2x(12x12+26x1) + 37x16 = 24x(12+16) + 26x(2+8) = 932
340 + 592 = 672 + 260

340g petrol produces 672g CO₂

On average, 1kg petrol yields a maximum of around 1.97kg CO₂. This is a maximum, assuming complete combustion. If any petrol is unburned, the amount of CO₂ is going to be less, and there will be increased quantities of other crap such as carbon monoxide and various nitrogen oxides. All of this other crap reduces the amount of oxygen available to make carbon dioxide.

Incidentally, the figures provide a simple way of converting fuel consumption to grammes of CO₂/km:

15 x l/100km = g/km CO₂
Or, in old money 4150/mpg = g/km CO₂

The Goat is bemused to learn that according to UK government figures, the Goatmobile produces 305g/km CO₂, which equates to 13.6mpg. Yet those same government figures state typical fuel consumption as 16mpg in the (worst case) urban cycle. The ‘extra-urban’ and ‘combined’ cycles produce 27.7mpg and 22.2mpg respectively. Yeah, yeah ‘your mileage may vary’. But why does the CO₂ figure exceed the worst fuel consumption by around 18%? If the 16mpg urban were adopted, CO₂ emissions = 260g/km. Perhaps this inflation of the CO₂ figure is a vain attempt to get a prospective purchaser on to a guilt trip so that he’ll buy an electric moped instead. Incidentally, practical long-term testing by Muggins since 2004 shows an overall average of 237g/km CO₂; a total of nearly 30 tonnes of carbon dioxide. Take that, Ursus maritimus!

Then there’s the house in Cyprus. Accusations that the Goat is turning into a tofu-knitting, lentil-wearing bunny hugger, whilst not exactly unfounded, are circumstantial at best. The interest in solar energy is borne out of solar water heaters being more-or-less mandatory and the nearest existing power pole being about $30,000 away. Whilst photovoltaic cells are unlikely to pay for themselves if ‘proper’ electricity is available on the premises, being self-sufficient in power makes us immune to dodgy supplies, brownouts and inflated bills. You can buy a lot of PV panels with $30,000. Similarly with water. The nearest well is a good $10,000 away and the plot is lower than the well’s ground level elevation, so a borehole may be the answer. Cyprus’ water supply problems make it realistic for the government to subsidise private boreholes because this reduces demand on the piped network. There may even be a grant to get mains electricity to the plot in order to power the water pump. I wonder if there are EU grants available for installing a grey-water recycling system?

I’m advised that decent thick walls with plenty of insulation will keep the heat indoors during the winter and outside all summer, thereby making air conditioning unnecessary. The house will nevertheless be ducted for aircon in case this advice isn’t entirely accurate. Furthermore, someone is going to have to do the sums to see how many PV cells, batteries and inverters we’ll need.

Having contrived to produce a carbon footprint about the size of a pogo stick’s, the Goat has all the justification necessary for owning a big 4x4 pickup. Huzzah! The Goat also idly wonders how much land and effort would be required to grow his own bio-diesel to power said 4x4 pickup and the backup electricity generator…?

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