This means less energy is thrown off the sides in the form of eddy currents, which in turn reduces the reflected energy coming off of the side walls, which in turn improves imaging. Therefore, truly full-range dipole speakers must be larger than box speakers. The problem would be solved if the electrostatic panel was mounted in a wall or a large open baffle. The membrane must be charged with a dense field of electrons in order for the speaker to function. This charge is created by a power supply that uses the AC power mains.
Current drain is minimal.
The typical current taken from the mains is on the order of 15 milli-amps. The distance is not particularly critical. I would suggest about 3 feet. Toe the speakers toward each other slightly. If the speakers must be placed against the back wall, make the toe-in angle large, on the order of 35 degrees.