NOVELTY - The system has a solar cell panel (1) which is provided in a solar cell array connected with multiple solar cell strings. An alternating-current (AC) unit (41) provided with solar cell panel converts direct-current (DC) power generated from each solar cell panel into AC power. Each solar cell panel has an earth wire (43) for panels which is connected between negative electrode sides of AC unit and solar cell panel and is branched to ground the solar cell panels. A recording device and a monitoring apparatus are connected to the earth wire.    USE - Solar energy power generation system.    ADVANTAGE - As the earth wire for panels is connected between negative electrode sides of AC unit and solar cell panel and is branched to ground the solar cell panels, the connection wiring of the solar energy power generation system can be performed easily so that the workability and the electric power generation amount of the solar cell panel can be improved. As the back surface electrode side of the AC unit closely approached to the grounding potential, the quality change and deterioration of the solar cell can be suppressed so that the reliability of the solar cell panel can be improved. As the recording device and monitoring apparatus are connected to the earth wire, the reliability of the solar energy power generation system can be improved. As the AC unit is provided with the solar cell panel, the sudden fluctuation in the output can be absorbed for every solar cell panel so that the performance of the solar energy power generation system can be improved, even if the electric power generation amount of the solar cell panel is decreased, and the sudden fluctuation arises in the output.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) method of earthing photovoltaic power generation panel;    (2) method of monitoring solar cell panel by solar energy power generation system;    (3) method of cooling AC unit; and    (4) method of leveling generated electric power of solar cell panel.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the solar cell panel provided with AC unit.    Solar cell panel (1)    Terminal box (23)    AC unit (41)    Earth wire for panels (43)    Output cable (45)