What Affects Solar Panel Output?

7 Things You Need To Know About Solar Panel Ratings There are two types of solar panels commonly used for domestic installations - monocrystalline (up to 22%) and polycrystalline (15 to 17%). There are two types of solar panels commonly used for domestic installations - monocrystalline (up to 22%) and polycrystalline (15 to 17%).

Panels are mostly sold by their STC rating in watts (Standard Test Conditions). These are ideal conditions that rarely exist in real life Panels are mostly sold by their STC rating in watts (Standard Test Conditions). These are ideal conditions that rarely exist in real life Irradiance 1000W/m2 Irradiance 1000W/m2 Solar Panel STC Rating Temperature 25 degrees C

NOCT solar panel rating standards are much more realistic - actual wattage output is around 25% less than the normal rating! NOCT solar panel rating standards are much more realistic - actual wattage output is around 25% less than the normal rating! Temperature 20 degrees C Insolation 800W/m2 Breeze 1m/sec Temperature 20 degrees C Insolation 800W/m2 Breeze 1m/sec

Solar Panel tilt angle affects the output. About 45% is good - adjusting by season is better. Solar Panel tilt angle affects the output. About 45% is good - adjusting by season is better. Flat isn't disastrous but 90 degrees is a big no-no! Flat isn't disastrous but 90 degrees is a big no-no!

Solar panel direction has an effect on output Solar panel direction has an effect on output Due South (in the Northern hemisphere) is optimum. South-East and South-West are OK, but never North! Due South (in the Northern hemisphere) is optimum. South-East and South-West are OK, but never North!

Auto-tracking (following the sun across the sky) increases energy output Auto-tracking (following the sun across the sky) increases energy output Single-axis tracking gives about 40% gain Dual-axis tracking can give up to 60% gain. Single-axis tracking gives about 40% gain Dual-axis tracking can give up to 60% gain.

Excess heat affects solar panel output Excess heat affects solar panel output A solar cell output capacity reduces by 0.5W for every degree rise in temperature (centigrade) A solar cell output capacity reduces by 0.5W for every degree rise in temperature (centigrade)

Clean those panels! Clean those panels! Regular cleaning can increase electricity generation by 10% to 25% Regular cleaning can increase electricity generation by 10% to 25% SolarDirect.com Since 1986