One source of energy that is absolutely essential
to our way of life is electricity (see the Aftermath page).
You only have to think of the problems that are caused by a power cut
of a few hours. Can we switch our electricity generation from fossil
fuels to renewables in the short time we have available? Using freely
downloadable data, let us examine the problems facing the UK.
Go to the UK
government trade and industry site and you can download Excel files
that give you information on the generation and consumption of electricity
in 2004. Examining these can show us some of the problems ahead. The results
are somewhat simplified to enable everyone to follow the reasoning and
allow you to follow your own process. For instance, power plants,
especially renewables, do not run continuously so the capacity is a theoretical
(Note: pumped storage
hydro stations have been removed from the data as they
rather than electricity generators.)
One of these files shows the number of power stations in the UK and
the fuel they use. These have been summarised in the charts below.
The most noticeable feature of these two charts is the poor showing
of renewables. While the maximum hydroelectric station is not large
at Sloy), the next largest is 75MW and the mean is
just 20MW so there are many small hydro plants and little opportunity
to build any
country like the UK. Wind fares even worse. The largest wind plants at
present (2004) in the UK are two offshore farms at 60MW which doesn't
come anywhere near even the average for the fossil fuel and nuclear categories.
The complete absence of solar power stations and the low number (in count
and output) of biomass/waste is significant. At the moment, it is clear
how dependent the UK relies on the finite and polluting fuels of coal,
gas and nuclear.This is emphasised even further in chart L3 which
shows that 81% of the total capacity is produced by fossil fuels and
only 3% by renewables.
If we are to replace fossil-fuel powered power stations with renewables,
it is hard to see from the figures used above how we could do so in the
short time left. (It is true that there will be improvements to the technology
to produce more output, but there also be an increase in demand). There
is little room in the UK to expand hydroelectricity which is very dependent
on geographical situation except as local generators contributing small
amounts to the national total. Wind power has a larger potential; 500
and 600MW farms are being planned, but even these massive enterprises
would only be the size of the average gas-powered station. Solar-powered
stations do not exist as yet. The world's largest solar plant is being
planned which would produce 116MW. But this is in sunny Portugal and
would cover a area of 250 hectares. The potential in the UK is much lower
and, again, even 116MW is much lower than the average gas, coal or nuclear
station. Bio/waste plants are few and small scale, and tidal power is
still far from making a significant contribution.
The one fuel that has been left out of the calculations so far is the
tricky subject of nuclear. As it is neither infinite nor pollution-free,
replacing fossil fuels would be jumping from the frying pan into the
fire. Even if we went for that, to go from the 16% for present nuclear
to replacing the 80% of fossil fuels would require an enormous number
of new stations. A very simple calculation shows that fossil fuels presently
produce around 60,000MW. Divide that by the average 1000MW nuclear station
will give you 60 new stations (five times the present number).
If we wished to move over to a clean hydrogen
economy and keep anywhere near the present number of vehicles on the
road, we would have to increase the number of renewable power stations
by a far greater amount. Since using electricity to create hydrogen to
propel vehicles is rather inefficient (with a final value of something
like 30% of the original energy of the electricity), it is hard to see
how we could create such a system with even nuclear power, let alone renewables.
Have a look at the page on efficiency for more information.
Information on Specific Fuels
Unconventional Oils : Natural
Gas : Coal : Nuclear : Renewables : Hydrogen