Showing posts with label electricity generation. Show all posts
Showing posts with label electricity generation. Show all posts

Thursday, 23 July 2009

Bristol - London Electrification

The planned electrification of the mainline railway between London and Bristol (and also on to Swansea and with spurs to Oxford and Newbury), announced today, may sound like good news from an environmental perspective. Electric trains operate more efficiently because they don't have to carry their own fuel and fuel-energy converter (diesel engine) which reduces their weight and hence their energy consumption for a given speed. So they can save energy, or go faster, or a bit of both.


Existing electrification near Paddington (Westbourne Grove)

That's my first quibble. It looks like some of the potential energy saving may be consumed by higher speeds and faster acceleration, so saving all of 19 minutes on the Swansea to London run - small beer for a journey that takes at least 3 hrs. If we are serious about reducing our energy consumption then we have to question the endless pursuit of higher speeds. Yes, there is an argument for making trains faster to compete more successfully with more environmentally malign modes of travel, but if we priced all (road, rail and air) according to the environmental damage caused then that wouldn't be an issue.

It is claimed that the energy consumed by electric trains can be generated by renewables like wind, wave and tidal energy. But can it? Energy consumed by electric trains will be above and beyond what would otherwise be consumed, which is already way beyond the generating capacity of renewables, even if we add in nuclear. For the foreseeable future renewables and nuclear will continue to supply only a minor part of our electricity generating capacity, so in effect any additional electrical demand means more generation from fossil fuelled capacity. Thus it follows that the additional electricity generated for rail will be mainly from carbon emitting sources.

Last but by no means least there is the question of the capital cost, some £1.1 billion over the next 8 years we are told, although we all know what happens to cost estimates and timescales. Labour do not expect to be in government for the next 5 years or so, so it's easy for them to 'commit' a future Conservative government to public expenditure. They must know that huge public expenditure cuts are on the horizon, whoever wins the next election. But Labour don't expect that to be their problem. I guess they expect that the Conservatives will have to cancel or postpone this project, which will of course give Labour an opportunity to attack the Tories. Is that is what is really behind this announcement?