bioethanol). The energy for transport is 18 kWh/d/p of electricity and
2 kWh/d/p of liquid fuels. The electric vehicles’ batteries serve as an energy
storage facility, helping to cope with fluctuations of electricity supply
and demand. The area required for the biofuel production is about 12% of
the UK (500 m2 per person), assuming that biofuel production comes from
1%-efficient plants and that conversion of plant to fuel is 33% efficient.
Alternatively, the biofuels could be imported if we could persuade other
countries to devote the required (Wales-sized) area of agricultural land to
biofuels for us.
In all five plans, the energy consumption of heating is reduced by im-
proving the insulation of all buildings, and improving the control of tem-
perature (through thermostats, education, and the promotion of sweater-
wearing by sexy personalities). New buildings (all those built from 2010
onwards) are really well insulated and require almost no space heating.
Old buildings (which will still dominate in 2050) are mainly heated by air-
source heat pumps and ground-source heat pumps. Some water heating is
delivered by solar panels (2.5 square metres on every house), some by heat
pumps, and some by electricity. Some buildings located near to managed
forests and energy-crop plantations are heated by biomass. The power re-
quired for heating is thus reduced from 40 kWh/d/p to 12 kWh/d/p of
electricity, 2 kWh/d/pE of solar hot water, and 5 kWh/d/p of wood.
The wood for making heat (or possibly combined heat and power)
comes from nearby forests and energy crops (perhaps miscanthus grass,
willow, or poplar) covering a land area of 30 000 km2, or 500 m2 per person;
this corresponds to 18% of the UK’s agricultural land, which has an area
of 2800 m2 per person. The energy crops are grown mainly on the lower-
grade land, leaving the higher-grade land for food-farming. Each 500 m2
of energy crops yields 0.5 oven dry tons per year, which has an energy
content of about 7 kWh/d; of this power, about 30% is lost in the process
of heat production and delivery. The final heat delivered is 5 kWh/d per
In these plans, I assume the current demand for electricity for gadgets,
light, and so forth is maintained. So we still require 18 kWh(e)/d/p of
electricity. Yes, lighting efficiency is improved by a switch to light-emitting
diodes for most lighting, and many other gadgets will get more efficient;
but thanks to the blessings of economic growth, we’ll have increased the
number of gadgets in our lives – for example video-conferencing systems
to help us travel less.
The total consumption of electricity under this plan goes up (because
of the 18 kWh/d/p for electric transport and the 12 kWh/d/p for heat
pumps) to 48 kWh/d/p (or 120 GW nationally). This is nearly a tripling of
UK electricity consumption. Where’s that energy to come from?
Let’s describe some alternatives. Not all of these alternatives are “sustainable”
as defined in this book; but they are all low-carbon plans.