How to Read a Solar Panel Meter

Solar power is gaining popularity globally as more companies and homeowners realize its benefits. However, some people have solar systems but need help reading solar panel meters. A solar panel meter is a device for measuring the sunlight or solar power in W/m2 units, either via windows to verify its efficiency or during the installation of solar power devices. It indicates pyranometers, which measure the solar radiation flux density or the devices for measuring kWh production from the photovoltaic system. This meter accumulates PV yield production and consumption to analyze or monitor a PV plant's performance.

Reading a Solar Panel Meter

A solar meter displays an alternate between negative and positive numbers. A positive number denotes a company or household has electricity imported from the national grid. Usually, you can see this on a typical electricity meter without a solar system. A negative number indicates the amount of electricity a company or household has exported from its solar system to the national grid. It shows the amount of electricity a solar system has generated beyond what it consumes or needs. When the negative value is higher than the positive value, a household or property has exported more electric power than it has imported. Thus, the household or property owner can get the local power company refunds.

About Solar Power Measurements

The solar radiation reaching the absorbent surface signifies the energy output. You can instrumentally measure the solar radiation on the surface of the earth. Precise solar radiation measurements provide crucial background data for solar energy conversion applications. Two instruments help with solar radiation measurement as follows:

Pyranometer

A pyranometer measures the total hemispherical radiation. A pyranometer will measure diffuse radiation if there is a shadow. Most source data is from a pyranometer. Using a pyranometer, you can calculate total irradiance or W/m2 on a horizontal surface.
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A pyranometer can have photovoltaic detectors and thermocouple indicators. Sensors should be independent of the solar spectrum's wavelength and incidence angle. Also, pyranometers can measure solar radiation for inclined surfaces, which is crucial in determining relevant information. Pyranometers' calibration relies on the inclination angle. Therefore, experimental data is necessary when interpreting measurements.

Pyrheliometer

Pyrheliometer measures direct beam radiation within the normal incidence. Different types of pyrheliometers exist. However, the primary or standard instruments are Angstrom compensation and Abbot silver disc pyrheliometer. Kipp and Zonen actinometer and Eppley normal incidence pyrheliometer are typical instruments for practical measurements. Depending on the design of the pyrheliometer, it can measure the sun's beam radiation and a small part of the sky surrounding the sun. According to studies of several pyrheliometer designs, the circumsolar sky's contribution to the beam is insignificant during a sunny day when the skies are clear. Nevertheless, a gloomy day redistributes beam radiation so that the circumsolar sky's contribution to the measurement becomes more significant.

Conclusion

A solar panel meter is a vital device that measures solar power units. It's bi-directional, meaning it counts the household's solar energy production and export. Upon your new solar panel installation, a solar panel meter can help you reduce the money you spend on electricity. It can help you claim a refund from the national grid or utility company for exporting the excess energy.