Solar energy is the world's fastest-growing energy source and the most readily available supply of renewable energy. This rapidly emerging energy source still only accounts for a fraction of the world's total energy consumption however this too is growing as more regions and countries adopt solar energy generation to refuel the grid. Power generation through this means needs to be quantified in order to assure that the correct credits are given and that incentives are met, the best way to do this is by monitoring the generation and the amount being distributed back into the grid.
Solar meters to the pyranometers are used to measure solar radiation flux density or devices used to measure the kWh production from a PV system. Solar meters collect PV yield production and local energy consumption to monitor and analyze PV plant performance. Solar meters often come with a monitoring function to alert plant owners of issues with PV plant performance, letting them quickly resolve issues and maximize return on investment. Plant data is transferred to a monitoring platform that provides a concise presentation of PV yield, monetary savings, and plant performance. Solar meters record electricity readings using integrated current transformers. They can be cellular-enabled, which allows for a dependable communication from the plant to the monitoring platform, where the installer and customer can view performance remotely via the web. To measure electrical power, the rate of production, two aspects are measured: current and voltage. Current is generally measured by sensing the strength of the magnetic field produced when electricity flows through a conductor current sensor installed around a conductor is the current transformer. The voltage is measured directly by the meter via two more connections to the electrical service. The meter multiplies the current by the voltage to calculate apparent power (VA) and compares the current and voltage signals to calculate the power factor. The apparent power is multiplied by the power factor to calculate real power. Real power is integrated over time to calculate real energy.
Measuring meters can be internal or external to the inverter. All inverters include an external meter, but frequently these meters are not revenue grade. External meters can be installed along the AC line between the inverter and the main distribution panel. This allows for one meter to measure the output from multiple inverters, which can create significant cost savings, as well as a collection of more precise PV yield data if the meter is “revenue-grade’.