Yes, weather conditions will affect the system. Every PV solar system’s energy output is subject to the instantaneous variations in solar radiation. On a cloudy day, the panels will produce electricity, however, the production will not be as high as when the panels are in bright sunlight. The PV system’s long term performance varies seasonally. The situation can be further complicated if there is periodic shading caused by trees, buildings and other features which may interrupt the path of direct sunlight onto the panels.
A grid connect system requires very little maintenance. The solar panels may from time to time need cleaning. Always observe all Occupational Health and Safety requirements such as working from heights, e.g. roof mounted systems. When solar panels are tilted 15 degrees or more, rain run-off can help keep them clean, however, local conditions will ultimately dictate the frequency and degree of cleaning.
For safety reasons, the grid connect inverter automatically shut itself off during a blackout, so as prevent back feeding the grid. The system switches off until mains electricity is restored.