Assuming there is some, how should I set a budget or cost expectation for solar panel maintenance?
Wash one a year after the spring, once trees have bloomed in your area. Use a garden hose and dishwashing detergent (very little) - you’re just cleaning the glass for maximum light transmission.
Micro-Inverters: Virtually no maintenance required besides annual cleaning.
Central Inverter: Must be replaced every 10-15 years, plus annual cleaning.
Solar panel installations for residential or small commercial use require little/no maintenance. Equipment should be expected to live up to the manufacturer’s warranty without special care. The only regular maintenance that you may want to perform is cleaning your panels once or twice a year. A thorough cleaning can increase panel performance by up to about 5%. Usually, a good rinse down (preferably with R/O or filtered water) in the early morning during your dry season will do the job. You can go a bit further and clean them yourself using a specialized cleaning product (example here: https://amzn.com/B01K1Y5SLK). You can also hire a professional to do this for you, however, you should consider the added cost ($100-$300/per cleaning) and how this will affect your overall savings.
Solar Panels require very little maintenance. Only the occasional cleaning is necessary during extended periods of dry weather.
We recommend at least one annual cleaning in July or August. More reason to do so if we get a light rain late in the season, which can leave panels looking muddy.
For larger systems some installers include complimentary annual cleanings for the first few years.
Solar panel systems require no maintenance, however if you feel that you must have your solar panels cleaned every so often, feel free to do it. When solar panels are dusty or have pollen on them your solar panel will lose about 1/2 of 1% energy production. So if you have a 300 watt solar panel it will produce about 1.5 watts less until it is cleaned. It’s not even worth the time, the effort or risking getting on your roof to clean them. Just wait until it rains again and they will self-clean.
Micro Inverters- Little to zero maintenance required besides annual cleaning.
Central Inverter- Replacment every 10-15 years, plus annual cleaning.