When you want to retrieve data from a database, you ask for the data by using Structured Query Language, or SQL. SQL is a computer language that closely resembles English, but that database programs understand. Every query that you run uses SQL behind the scenes.
The inverter turns the DC electricity generated by the solar panels into 120-volt AC that can be put to immediate use by connecting the inverter directly to a dedicated circuit breaker in the electrical panel.
A solar panel is generally 250 watts. The cost of 1 watt is these days is around $1.5/watt for small sized solar array used in residential and small commercial installations. Hence a solar panel costs around $350-400/watt.