Introduction
The Sun serves as both light and heat source to the earth giving us the sunlight and warmth we need to survive. Between Sunrise and Sunset, the Sun radiates good amounts of photons that illuminates the earth and distinguishes day from night. However, the photon from the Sun goes beyond physical light that brightens the day, it gives yield to solar irradiation (sun radiated energy) that causes photovoltaic cells to produce electrical energy.
The sun is an excellent source of energy that we can harness in so many ways, but we need to know the available radiant energy in our respective locations for proper sizing of our solar photovoltaic (PV) panels for electricity generation.
What is Solar Irradiance?
The radiant power emitted by the Sun per unit area arriving on a surface at a particular angle, falling on a 1 square meter perpendicular plane every second outside Earth’s atmosphere is known as Irradiance. It is measured in watts per square meter (W/m2), or kilowatts per square meter (KW/m2).
The amount of solar irradiance generated annually during the natural cyclic rotation of the earth changes due to the variations of the direct distance between the Earth and the Sun. In the outer space of the earth’s atmosphere, there’s little or no attenuation experienced by the radiated solar energy thus, the average irradiance measured on the edge of space and outside Earth’s atmosphere is known as “Solar Constant” with a value of about 1367W/m2. We can only get a fraction of this value inside the earth’s atmosphere.
The specification of PV modules is done by manufacturers under standard test conditions (STC) i.e., at solar irradiance equals 1000W/m2. The irradiance of the sun available in a specific location tells how much power a rated solar panel can produce in that location.
Irradiance Curve
Fig 1-Irradiance curve
Fig 2-Irradiance vs Current
The above plot shows the relationship between Sun Irradiance and the power output (current and voltage) of solar panels. We can clearly see from the plots that the increase in irradiance leads to an increase in the power produced by PV modules.
SolarBolts offers a detailed design that takes cognizance of the irradiance data for your location, this makes our design, sizing and costing of your system most appropriate, cost-effective and, highly efficient to meet your specifications.
Let’s go solar with SolarBolts!!!
