An 8kw solar system can generate 32 and 40 kWh of electricity per day, 11,680 and 14,600 kWh per year, and requires 20 400w solar panels, which cost $11,680 and $16,800 after tax credits. The expected 8kW solar system daily output would be close to 1,000 kWh per month or about 33 kWh daily. This is enough to run a refrigerator, microwave, lights, fans, TV, laptop, washing machine, small well pump and a window air. The average 8 kW solar system will cost about $16,800, including the 30% federal solar tax credit. Between 20 and 22 solar panels are used in an. The 8kW rating is determined under Standard Test Conditions (STC), which involves a panel temperature of 25°C and an irradiance of 1,000 watts per square meter. Generally comprising 20-24 panels, an inverter, mounting equipment, and a monitoring setup, this.