Will my 2 kW solar power system produce 2 kW of power every hour?
A 2 kW system will very rarely produce 2 kW/h of electricity in one hour. There are clouds and variance in the sun intensity, as well as inverter efficiency percentage and cable loss to take into consideration. Even in good sunlight conditions expect a 10% loss on average.
Generally a 2kW quality solar power system with a quality inverter generates between around 1.7 and 1.8 kW generation in sunny bright conditions. LG Electronics rate our panel output under standard temperature of 25 degree celsius and consistent conditions. Through tests, called flash test we are able to compare the output of a batch of solar modules.
It is the amount of light, together with the operating temperature that determines the electricity output generation of a solar cell. Solar cells, being usually dark in colour do heat up in sunny conditions and on the roof your panel could easily be heated from 40 degrees to as much as 90 degrees depending on the season. That’s why using quality backing sheets and long life sealants is so vital for the longevity of your panel.
At around 40 degrees solar cells in general produce around 5-8% less power than they generate at just 15 degrees lower – at 25 degrees. Heated up at 75 degree Celsius one can experience a loss of 15% or more. Therefore the best day for solar output is a clear bright day, with moderate temperature. Because of Australia’s overall high sun irradiation, solar systems here produce comparatively higher electricity output, when compared for example with northern parts of Europe.
For brief periods given the right conditions peak power could be gained or exceeded. For example if there was a short rain shower that cooled the panels, followed by a crisp clean sunlight, the 2kW system could for a period thereafter produce 2,1 kW, till the panels heat up. So in contrast to popular belief, solar panels do not love very hot days, but produce the best result in clear, medium temperature days.
Finally dirt does accumulate over time on the panels, and while most of it is washed off during rain, this can also lead to a small loss of potential output.