The MPLAB REAL ICE in-circuit emulator cannot power a target board. This makes it different from the other debuggers. Therefore, the target board will need to have its own power supply when using the emulator.
The optional accessory MPLAB REAL ICE Power Monitor (AC244008) allows the MPLAB REAL ICE In-Circuit Emulator to power the target board, as well as monitor current and voltage of the target or device.
Microchip Technology acquires Atmel