It is also recommended that the provision of services be described in detail. A service level agreement (SLA) can be used for this purpose, which can be added as an annex to the main SaaS contract. In an SLA, the parties define in detail how the services are to be provided, the level of performance to be achieved, and how they can be measured. In addition, the service provider is also responsible for troubleshooting, repairing and replacing defective or worn parts. To do this, it is also important that the supplier has enough spare parts in stock. The distribution company serving the host customer shall provide a connection between the photovoltaic installation and the grid and shall continue its electricity service with the host customer in order to cover the periods during which the system produces less than the electricity needs of the site. Some states have net-metering requirements that offer a credit method for customers who produce electricity locally that exceeds their own electricity consumption. . . .