All solar panels are rated by the DC power produced in standard test conditions. A typical solar panel produces about 200 watts of electricity based on the efficiency and size of what’s installed. For example, if you have 25 panels installed, you may have an output of about 5 kilowatt hours (kWh).ll solar panels are rated by the DC power produced in standard test conditions. A typical solar panel produces about 200 watts of electricity based on the efficiency and size of what’s installed. For example, if you have 25 panels installed, you may have an output of about 5 kilowatt hours (kWh).