The only problem will be -putting off forever BEMU ordering because something better is just around the corner.
Agree it is fast moving market.
An example is this CAF BEMU tested on Siemens test track that achieved 273km on battery.
Test with series-production Class 557 vehicle for VRR (Verkehrsverbund Rhein-Ruhr) provides valuable insights for future BEMU projects.
CAF has conducted a range test with a battery-electric multiple unit (BEMU) of the Civity platform at the Siemens Test and Validation Center in Wildenrath (Germany). The vehicle tested was a short-type Class 557 unit equipped with the standard production LTO (Lithium Titanate Oxide) traction batteries.
During the test run, the vehicle achieved a range of 273 km operating exclusively on battery power. In addition, the performance of the traction system was evaluated under extreme operating conditions. The data and insights obtained will be directly incorporated into the further development of efficient battery-electric propulsion technologies.
https://www.cafmobility.com/en/press-room/caf-achieves-273km-in-battery-mode-test-wildenrath/
But there are 2 ways of looking at when to order :
1) either accept someone else has done the development and will just use their design and spec (adjusted to UK loading gauge),
2) or place an order for something still in development and take the risk of not working properly, or delayed, or doesn't meet the spec put in your order.
My hunch is at the point where waiting longer (whilst patching up old diesel trains to keep them operating few more years), is now outweighed by accepting market has got to sufficiently developed status
