0.7 kWh from dairy; 0.2 kWh from eggs; and 0.5 kWh from meat – a total
of 2.9 kWh per day.)

This number does not include any of the power costs associated with
farming, fertilizing, processing, refrigerating, and transporting the food.
We’ll estimate some of those costs below, and some in Chapter 15.

Do these calculations give an argument in favour of vegetarianism, on
the grounds of lower energy consumption? It depends on where the ani-
mals feed. Take the steep hills and mountains of Wales, for example. Could
the land be used for anything other than grazing? Either these rocky pas-
turelands are used to sustain sheep, or they are not used to help feed
humans. You can think of these natural green slopes as maintenance-free
biofuel plantations, and the sheep as automated self-replicating biofuel-
harvesting machines. The energy losses between sunlight and mutton are
substantial, but there is probably no better way of capturing solar power
in such places. (I’m not sure whether this argument for sheep-farming in
Wales actually adds up: during the worst weather, Welsh sheep are moved
to lower fields where their diet is supplemented with soya feed and other
food grown with the help of energy-intensive fertilizers; what’s the true
energy cost? I don’t know.) Similar arguments can be made in favour of
carnivory for places such as the scrublands of Africa and the grasslands of
Australia; and in favour of dairy consumption in India, where millions of
cows are fed on by-products of rice and maize farming.

On the other hand, where animals are reared in cages and fed grain
that humans could have eaten, there’s no question that it would be more
energy-efficient to cut out the middlehen or middlesow, and feed the grain
directly to humans.

Fertilizer and other energy costs in farming

The embodied energy in Europe’s fertilizers is about 2 kWh per day per
. According to a report to DEFRA by the University of Warwick,
farming in the UK in 2005 used an energy of 0.9 kWh per day per person
for farm vehicles, machinery, heating (especially greenhouses), lighting,
ventilation, and refrigeration.

The energy cost of Tiddles, Fido, and Shadowfax

Animal companions! Are you the servant of a dog, a cat, or a horse?

There are perhaps 8 million cats in Britain. Let’s assume you look after
one of them. The energy cost of Tiddles? If she eats 50 g of meat per day
(chicken, pork, and beef), then the last section’s calculation says that the
power required to make Tiddles’ food is just shy of 2 kWh per day. A
vegetarian cat would require less.

Similarly if your dog Fido eats 200 g of meat per day, and carbohydrates

Figure 13.6. Will harvest energy crops for food.
Figure 13.7. The power required for animal companions’ food.