Are there any parts that need to be replaced regularly and when?

There are no parts needing regular replacement. While panel warranties are 20-25 years, we expect a much longer lifespan of 40+ years. PV panels put into space in the 60’s are still going strong today. Inverters have warranties for 10 years on residential and 5 years for commercial. Inverters have computer displays showing diagnostic fault codes which make servicing extremely simple. Most repairs will be of the plug and play variety. Digital output readings from inverters should be regularly monitored in conjunction with your electric bill.