Tyndall The Tyndall Centre’s estimate of the total practicable renewable-
energy resource is 15 kWh per day per person.
IAGThe Interdepartmental Analysts Group’s estimates of renewables,
take into account economic constraints. Their total practical and eco-
nomical resource (at a retail price of 7p/kWh) is 12 kWh per day per
PIUThe “PIU” column shows the “indicative resource potential for renew-
able electricity generation options” from the DTI’s contribution
to the PIU review in 2001. For each technology I show their “practical
maximum,” or, if no practical maximum was given, their “theoretical
CATThe final column shows the numbers from the Centre for Alternative
Technology’s “Island Britain” plan Helweg-Larsen and Bull (2007).
Sometimes people ask me “surely we used to live on renewables just fine,
before the Industrial Revolution?” Yes, but don’t forget that two things
were different then: lifestyles, and population densities.
Turning the clock back more than 400 years, Europe lived almost en-
tirely on sustainable sources: mainly wood and crops, augmented by a little
wind power, tidal power, and water power. It’s been estimated that the
average person’s lifestyle consumed a power of 20 kWh per day. The wood
used per person was 4 kg per day, which required 1 hectare (10 000 m2) of
forest per person. The area of land per person in Europe in the 1700s was
52 000 m2. In the regions with highest population density, the area per per-
son was 17 500 m2 of arable land, pastures, and woods. Today the area of
Britain per person is just 4000 m2, so even if we reverted to the lifestyle of
the Middle Ages and completely forested the country, we could no longer
live sustainably here. Our population density is far too high.
Figure 18.1 is bleak news. Yes, technically, Britain has “huge” renewables.
But realistically, I don’t think Britain can live on its own renewables – at
least not the way we currently live. I am partly driven to this conclusion by
the chorus of opposition that greets any major renewable energy proposal.
People love renewable energy, unless it is bigger than a figleaf. If the British
are good at one thing, it’s saying “no.”