I know that things like high tension wires can affect saleability but does they show up in county appraisal/assessments? Sale appraisals?(I think theres a difference)
For tax assessment purposes, I don't think there will a difference in taxes or values of like properties.
However, an appraiser most likely will make some small adjustment in the market value, when comparing the subject property to 3 others that don't have high tension wires.
These adjustments can be quite subjective, just like a home with a "view" vs. one without it.