The cost to electrify a train line wins under the decision test Britain built
The cost to electrify a train line, the cable strung above the tracks that lets an electric train draw power directly instead of burning diesel, is not the barrier the diesel case assumes. Network Rail, the public body that owns and runs the rail network in Great Britain, built a decision framework in 2020 that sorts every unwired route into 1 of 3 fixes, wire, battery or hydrogen, based on how many trains use it and how far it runs. The framework counts track in single track kilometres, each parallel line on a route counted separately. Applied to all 15,400 single track kilometres of unelectrified track in the country, it recommends wiring 11,700 of them, at a stated cost of 1 million to 2.5 million pounds per kilometre. Battery operation is reserved for only 400 kilometres and hydrogen for 900, because both fit only the routes carrying the fewest trains. Wire wins on the large majority of unwired track by length, in the numbers the strategy itself gives.
2,300 more single track kilometres carry no clear technology choice yet in the strategy and are left off this chart, since source 1 itself has not assigned them to any of the 3 fixes.
Show the numbers
| Electrification | 11,700 |
| Hydrogen | 900 |
| Battery | 400 |
A finished American project shows what wiring actually costs
That per kilometre bracket is a planning estimate, not a finished bill. Caltrain, the public transit agency that runs the unwired line between San Francisco and San Jose in California, shows what a finished project actually costs. Electrifying that line now totals 2.44 billion dollars, an increase of 462 million dollars over the total the agency was citing before, according to Caltrain own account of its project. Caltrain names the reasons as delays and unforeseen conditions along its right of way, the strip of land and track the railway owns, more than 150 years old in places. Subtracting the increase from the new total implies a prior total of about 1.98 billion dollars, a calculation this site performed from the 2 figures Caltrain states, not a number the agency itself gives. Electric service on the line began in 2024.
The civil work is nearly complete and Caltrain and its partners will be focused on completing the signal, system integration and testing.
Michelle Bouchard, Acting Executive Director of Caltrain, speaking about the electrification project. Source 2.
The battery alternative is not free either
A battery powered train avoids wire only until its batteries wear out. Rail Engineer, a British trade publication that tracked the strategy after publication, worked out a real cost for an 8 car battery bi mode train, built to run on wire where it exists and switch to onboard batteries where it does not, on a half electrified 250 kilometre route. Its batteries alone weigh 9 tonnes, cost 2.7 million pounds, and need replacing every 5 to 10 years, a recurring cost a simple comparison of wire against no wire leaves out. The whole programme present value, a single figure adding up decades of future cost and benefit as if paid today, runs 6.3 billion to 9.7 billion pounds against a benefit of 6.9 billion to 7.3 billion pounds, and the government called it unaffordable. Britain has not committed to the full programme since.
Discounted present value figures for the whole electrification option across a multi decade appraisal, not a simple sum of the per kilometre cost bracket in chart 1. The 2 kinds of number measure different things and are never combined into 1 figure.
Show the numbers
| Cost | 6.3 to 9.7 billion pounds |
| Benefit | 6.9 to 7.3 billion pounds |
The United States has barely started wiring freight track
The United States shows how far behind wire can fall. About 1% of freight rail track is electrified there, drawn from a University of New South Wales engineering paper own review of earlier studies. The Association of American Railroads, the industry trade group, told FreightWaves that stringing overhead wire is not viable for the long haul freight network in the country, for technical and logistical reasons. Jim Blaze, a rail economist, disagrees and puts 15% to 30% of Class I route miles, the track owned by the largest freight railroads in the country, within reach.
Previous rail company reports showed clear circumstances whereby overhead electrification could work and could be financed with reasonable internal rates of return.
Jim Blaze, a rail economist, answering the industry position that electrification does not pay. Source 3.
A battery electric train, the same academic paper finds, can cover only about a tenth of the distance a diesel electric locomotive covers on a full tank, before it needs recharging again.