While I'm not expert on methods involving electricity, I'd imagine it is not as reliable nor peaceful as other methods (N, SN, SA, inert gases - N2, Ar, CO) and also like others have said, it will be very painful and still unlikely to result in a successful ctb. Electricity reminds me of the old execution method, the electric chair where the death row inmate would be strapped to a chair, hair shaved, then given an 'natural' sponge soaked in salt water and then have an helmet attached to his/her head and then given lots of electricity. It looks like it will be very painful before the condemned finally passes.
@Pulpit2018 is actually is right and there is a video (too graphic to show here) of a guy who fried to death on a roof while holding the power lines as he cooks from inside out, then after a while, his body limp, falls from the roof, presumably dead after such a long fry. It doesn't look like a pleasant way to go.