the typical maximum power radiated by a power line would be less than 0.0001 microwatts/cm^2, compared to the 0.2 microwatts/cm^2 that a full moon delivers to the Earth's surface on a clear night.
This is not to say that there is no loss of power during transmission. There are sources of loss in transmission lines that have nothing to do with "radiation" (in the sense as it is used in electromagnetic theory). Much of the loss of energy is a result of resistive heating; this is in sharp contrast to radiofrequency and microwave antennas, which "lose" energy to space by radiation. Likewise, there are many ways of transmitting energy that do not involve radiation; electric circuits do it all the time.
This is not to say that there is no loss of power during transmission. There are sources of loss in transmission lines that have nothing to do with "radiation" (in the sense as it is used in electromagnetic theory). Much of the loss of energy is a result of resistive heating; this is in sharp contrast to radiofrequency and microwave antennas, which "lose" energy to space by radiation. Likewise, there are many ways of transmitting energy that do not involve radiation; electric circuits do it all the time.