Has anyone actually done the calculations of the power supply needed and the total cost of the electric energy used for running HS2 train services at these different speeds to see which speeds are affordable and deliverable?
With the power supply needed increasing as the cube of the speed and the total electric energy used and therefore the cost increasing as the square of the speed, small increments in speed lead to big increases in the total cost of the electric energy used and even bigger increases in the power supply needed. Selecting 360kph instead of 300kph leads to a 44% increase in the total cost of the electric energy used and a 73% increase in the power supply needed.
In view of the cost of generating more electricity and the cost of supplying it to the railway I think the trains will run on HS2 at 250kph or even 225kph because it will prove too difficult to supply enough electric power and too expensive in electric energy costs to run the trains at any higher speeds.
The cost of electricity is not normally considered to be a serious component of running a high speed railway.
Worth noting that a TGV Duplex at 320kph requires a similar amount of electricity per seat kilometre as a Class 390 at ~200kph.
A TGV Duplex trainset (I have the figures to hand) consumes about 22kWh to move a kilometre on French HSLs at up to 320kph. That would imply something like 3520kWh to get the train from London to Birmingham. Now I don't know what Network Rail pays for electricity, but that's about £1100 worth of electricity at my day rate.
Or £2 per seat. And that's with the traditional TGV seat layout from the 1990s, which is restricted by the size of electrical and HVAC equipment of the period - a TGV M would do much better from lower energy use and many more seats on a set.
The other factor is the journey time, as that then had an impact on the number of coaches and amount of staff needed.
The faster you travel the less that costs.
Using the current journey times but running 16 coach trains you would need 240 coaches to run 3tph to Manchester.
Using HS2 journey times you need 144 coaches to run the same service.
Assuming a cost of £100,000 per coach (historic lease costs, but likely to be higher, but I've used this number as it'll result in a lower cost difference), just to run those services with no spare units would cost £24,000,000 or £14,400,000.
Assuming that they run 3tph, 18 hours a day, 360 days a year, with 1,100 seats and in both directions (3*18*360*1,100*2= 42,768,000 passenger seats per day) then the cost difference per seat is 23p.
Likewise, to run an 18 hour service using current journey times would require 90 person hours per member of staff, using HS2 that would be 54 person hours per member of staff.
Over a year you have to have 20 single person staff for the current services and 12 single person staff for HS2, if we assume 3 staff per train (driver, guard and catering staff with an average cost (not just wages, so again probably low) of £60,000 per member of staff the extra cost is 1p per seat.
That means that in a per seat basis you can spend an extra 24p in energy costs (about 12%) and it not actually make a difference.
However, by running faster services you make train travel much more attractive and so you're likely to fill more of those seats. That changes the maths, however, generally there's likely to be some advantage.
Although, the overall difference (even if the electrical cost for the slower train was zero) is not significant.