On most airports (most airports I've flown to at least), you can't save 100-200kg during taxiout, since the taxi out itself will be this amount.
To save this kind of amount you would need a half hour taxi out.
Fuel consumption with both engines at idle without APU is 600kg/hour
Fuel consumption with one engine and APU is 400kg/hour. So you can save 200kg per hour, tops, assuming you taxi at idle and at the same speed (which is slightly wrong and in favor of the SETO)
So to save 100kg, with these hypotheses, you need at least a half hour taxi out.
There is no doubt I would perform a SETO with this kind of duration. But 99% of our taxi durations are below 15 min and 90% are between 9 and 12 minutes.
If you fly a very busy american airport with very long queues at the holding point, I fully understand your point. We do not encounter this situation at my airline.
Last edited by CVividasku; 11th Apr 2024 at 16:19.