23   Sustainable fossil fuels?

It is an inescapable reality that fossil fuels will continue to be an important part of the energy mix for decades to come.

UK government spokesperson, April 2008

Our present happy progressive condition is a thing of limited duration.

William Stanley Jevons, 1865

We explored in the last three chapters the main technologies and lifestyle
changes for reducing power consumption. We found that we could halve
the power consumption of transport (and de-fossilize it) by switching to
electric vehicles. We found that we could shrink the power consumption
of heating even more (and de-fossilize it) by insulating all buildings better
and using electric heat pumps instead of fossil fuels. So yes, we can
reduce consumption. But still, matching even this reduced consumption
with power from Britain’s own renewables looks very challenging (figure
18.7, p109). It’s time to discuss non-renewable options for power produc-

Take the known reserves of fossil fuels, which are overwhelmingly coal:
1600 Gt of coal. Share them equally between six billion people, and burn
them “sustainably.” What do we mean if we talk about using up a finite
resource “sustainably”? Here’s the arbitrary definition I’ll use: the
burn-rate is “sustainable” if the resources would last 1000 years. A ton of
coal delivers 8000 kWh of chemical energy, so 1600 Gt of coal shared be-
tween 6 billion people over 1000 years works out to a power of 6 kWh per
day per person
. A standard coal power station would turn this chemical
power into electricity with an efficiency of about 37% – that means about
2.2 kWh(e) per day per person. If we care about the climate, however, then
presumably we would not use a standard power station. Rather, we would
go for “clean coal,” also known as “coal with carbon capture and storage”
– an as-yet scarcely-implemented technology that sucks most of the carbon
dioxide out of the chimney-flue gases and then shoves it down a hole in
the ground. Cleaning up power station emissions in this way has a significant
energy cost – it would reduce the delivered electricity by about 25%.
So a “sustainable” use of known coal reserves would deliver only about
1.6 kWh(e) per day per person.

We can compare this “sustainable” coal-burning rate – 1.6 Gt per year
– with the current global rate of coal consumption: 6.3 Gt per year, and

What about the UK alone? Britain is estimated to have 7 Gt of coal
left. OK, if we share 7 Gt between 60 million people, we get 100 tons per
person. If we want a 1000-year solution, this corresponds to 2.5 kWh per

Figure 23.1. Coal being delivered to Kingsnorth power station (capacity 1940 MW) in 2005. Photos by Ian Boyle www.simplonpc.co.uk.
Figure 23.2. “Sustainable fossil fuels.”