If your panels aren't producing any electricity when you'd expect them to, it's most likely a fault with the inverter or a problem with the wiring. Occasionally the generation meter might fail.
According to the Betz Limit, proposed by German physicist Albert Betz in 1919, no turbine can capture more than 59. 3% of the kinetic energy from the wind, because some energy must remain in the airflow to allow it to continue moving past the blades.
This article describes energy and electricity production, consumption, import and export in Kenya. Kenya's current effective installed (grid connected) electricity capacity is 2,651 megawatts (MW), with peak demand of 1,912 MW, as of November 2019.
On average, 15-20 solar panels of 400 W are needed to power a house. This can vary depending on your solar panels' wattage rating, solar panels' efficiency, climate in your area, your total household electricity consumption, and how much of that you want to offset to your solar.
No — standard photovoltaic (PV) solar panels do not generate useful electricity at night because they require photons from sunlight (solar irradiance) to free electrons and create current.