My initial interest was the now-defunct DesignLine gas-turbine-engined vehicles used by Stagecoach on the Quaylink service.

Apparently they cost £5000 per week of operation (and were scrapped after 6 years service).

I suspect the current hybrids will be more reliable and last longer, but what about the whole life cost and the running costs?

Several operators seem to have tried them and rejected them as not being as cheap to run as they hoped.