About the only true demarcation would be between electricity and natural gas.
Many electric utilities use a combination of coal/petroleum as sources. Factor in nuclear for some, hyrdo for others. Stated another way, no pure plays.
I will say utilities in general are capital intense and thus interest rate sensitive.
Dow Theory is industrials confirmed by transports, but...........utitilies, as boring as they may be, often lead the idices higher or lower.