One method of reducing carbon emissions from transport is through replacing petroleum
fuelled vehicles with electric ones powered from low carbon energy sources. In this
post, we examine how much we would need to increase our nuclear and renewable capacity
to meet the UK's transport fleet requirements assuming they are completely electrified
and what carbon reduction would be achieved. Any increase in low carbon generating
capacity is first allocated to offset the highest carbon generating source which
is coal rather than petroleum, so this needs to be part of an overall carbon reduction
The default strategy for this analysis assumes that
15% of total electricity is obtained from wind, similar to that currently achieved
in Spain and
our Nuclear component is increased to 40% of the total.
The calculations are tabulated on this spreadsheet using half hourly generating figures
for each electric generating source. At present this only covers three months between
March and May 2010, but this will serve as a first approximation. At the bottom of
the spreadsheet highlighted in blue are the relative increase in nuclear and wind
electric generation relative to current methods, which can be varied by the user.
The total electricity demand, for non transport use is assumed to remain the same
than at present.
Any excess of power generated from zero carbon sources is first allocated to coal,
followed by electric road transport (since this replaces petroleum) and finally natural
This overall strategy reduces coal based electricity from 24% to 2%, eliminates the
need for petroleum for transport, and reduces the CO2 from electricity generation
and transport combined by 80%.
It is assumed for simplicity that the storage capabilities of vehicle batteries and
any other balancing systems are capable of utilising any excess of electricity for
charging vehicle batteries. This is probably unrealistic without a continental wide
grid for renewable electricity, or greater hydro electric storage facilities than
we have at present, so it is likely that some additional standby power stations may
be required without these systems.
There is no allowance in electricity demand due to economic growth, or a reduction
in transportation energy measures such COAST or LOCI discussed in the ENTRANS report.
These are assumed to cancel out so we can focus on the electrification element only.
The indirect emissions from imports are also excluded which is customary in these
analysis, but we should remember that climate change is very much a global issue
with consumers as well as producers having responsibilities.
I have focused here on electricity production for simplicity, however, a significant
proportion of carbon emissions in the UK is produced from natural gas for space heating
purposes. I will show in a later article how this can be integrated into the energy
mix to reduce overall carbon emissions through the strategic design of energy systems
in a similar manner to that as described for transport.
* Having examined the results of more recent trials, I suspect this 15% might be
an underestimate. However, electric battery vehicles are far more efficient and
best suited to urban type short distance trips, (which accounts for most of the distance
travelled) not higher speed long distance journeys). The latter is best addressed
through powering these through fossil fuels until direct electric transmission such
as the INITIATE concept, or sustainable 2nd or 3rd generation biofuels become available
to fuel one of the techniques described in section 5.4 or 5.5 of the main report