To my knowledge there has never been a study specifically related to spacer cables and their impact to tree trimming related costs. A few things to consider when making the business case however is that while spacer cables may provide some short term relief in costs related to tree trimming, they will never completely eliminate the need.

There are some excellent studies indicating the longer that maintenance is deferred, the more costs associated with “recovering” those deferred trees increase dramatically. So while you may see some reprieve initially in costs relating to emergency dispatch and tree trimming, it is still very important to plan regular maintenance activities on those circuits with spacer cables. This old adage seems to be the guideline when discussing costs associated with tree trimming: “pay now or pay a lot more later.”