1. big contribution from solar photovoltaics, we required half the area
    of Wales. To get a big contribution from waves, we imagined wave
    farms covering 500 km of coastline. To make energy crops with a big
    contribution, we took 75% of the whole country.
  2. Renewable facilities have to be country-sized because all renewables
    are so diffuse. Table 18.10 summarizes most of the powers-per-unit-
    area that we encountered in Part I.
  3. To sustain Britain’s lifestyle on its renewables alone would be very
    difficult. A renewable-based energy solution will necessarily be large
    and intrusive.
  4. 2.It’s not going to be easy to make a plan that adds up using renewables
    alone. If we are serious about getting off fossil fuels, Brits are going
    to have to learn to start saying “yes” to something. Indeed to several

In Part II I’ll ask, “assuming that we can’t get production from renew-
ables to add up to our current consumption, what are the other options?”

Notes and further reading

page no.

104UK average energy consumption is 125 kWh per day per person. I took this number from the UNDP Human Devel-
opment Report, 2007.
The DTI (now known as DBERR) publishes a Digest of United Kingdom Energy Statistics every year. [uzek2]. In
2006, according to DUKES, total primary energy demand was 244 million tons of oil equivalent, which corresponds to
130 kWh per day per person.
I don’t know the reason for the small difference between the UNDP number and the DUKES number, but I can explain
why I chose the slightly lower number. As I mentioned on p27, DUKES uses the same energy-summing convention
as me, declaring one kWh of chemical energy to be equal to one kWh of electricity. But there’s one minor exception:
DUKES defines the “primary energy” produced in nuclear power stations to be the thermal energy, which in 2006
was 9 kWh/d/p; this was converted (with 38% efficiency) to 3.4 kWh/d/p of supplied electricity; in my accounts,
I’ve focused on the electricity produced by hydroelectricity, other renewables, and nuclear power; this small switch in
convention reduces the nuclear contribution by about 5 kWh/d/p.

Losses in the electricity transmission network chuck away 1% of total national energy consumption. To put it another
way, the losses are 8% of the electricity generated. This 8% loss can be broken down: roughly 1.5% is lost in the
long-distance high-voltage system, and 6% in the local public supply system. Source: MacLeay et al. (2007).

105Figure 18.4. Data from UNDP Human Development Report, 2007. [3av4s9]

108In the Middle Ages, the average person’s lifestyle consumed a power of 20 kWh per day. Source: Malanima (2006).

110“I’m more worried about the ugly powerlines coming ashore than I was about a Nazi invasion.” Source: [6frj55].

Power per unit land
or water area
Wind 2 W/m2
Offshore wind 3 W/m2
Tidal pools 3 W/m2
Tidal stream 6 W/m2
Solar PV panels 5-20 W/m2
Plants 0.5 W/m2
0.24 W/m2
11 W/m2
Geothermal 0.017 W/m2
Table 18.10. Renewable facilities have to be country-sized because all renewables are so diffuse.