One way to access your demand is to find out the average consumption of your household in a year. This could be done by adding all the units your consumed monthly and dividing the final amount with 12. This will give uyour averrage annualy consumption. You have to compare the average monthly productionn of 1 KW of a solar panel and find out how much capacitty you may require to fulfil your monthly power units with solar. Solar installers typically assess energy consumption patterns and available roof space to recommend an appropriate system size. Factors such as budget and future energy needs also play a role in determining the system size.

Yes. Most of the inverters are smart enough to prompt the consumers about potential hazars. For example in case of high grid voltage, earthing issues and others, the rootop solar inverters indicate the type of problem the system is facing. In many cases ike high grid voltage of earhting issues, the sytem does not allow the solar generation unless the problems like safety issues are taken care of.