On Grid Solar PV System
Solar On-Grid rooftop System
Solar Rooftop PV(Photo Voltaic) system using On-grid is also termed as a Grid-tied system or Utility interactive or Grid back feeding or Grid intertie system. In this kind of sytem, the Solar is connected with utility grid ( typically the power lines) along with the loads and batteries if any are present. In pure on-grid solar PV system, batteries are not connected.
Solar PV system generation
In general solar peak, generation is between 10:00 AM to 2:00 PM. But, based on the type of system installed, surroundings, and all other design specifications taken care, generation can be anywhere between 7:00 AM till 5:00 PM too.
Working of pure On-Grid Solar PV Sytems:
In pure on grid solar PV system batteries are absent. Once the Solar generation starts all the generated energy tries to compensate the existing loads. Once all the loads are satisfied excess generation will be going to the grid. Grid by itself acts as a virtual battery taking in all the excess energy exported. When there is a shortage(or even when there is zero generation) in energy generation from the Solar rooftop for all the available loads excess required energy is imported from the grid. By end of every month based on total export and import billing will be done. This net will be calculated with the help of a Bi-directional meter.
Working of a Bi-directional meter
Difference between the traditional Unidirectional meter and the Bi-directional meter is unidirectional meter only displays the total energy imported from the grid. Whereas Bi-directional meter reads three readings. The total amount of energy exported (in kWh), total amunt of energy imported, and net energy difference of the export and import.
Types of pure On-Grid Solar PV systems
With the day to day development of the technology, Solar technology in rooftop sector improved drastically. There are hundred thousand types of rooftops and each of them has varying surrounding conditions like different roofs, different directions of the roof, shadow issues etc. There are mainly three different types of pure on-grid solar PV systems addressing different situations.
Using String Inverters
String inverters are connected to series of panels. These inverters collect the accumulated DC Voltage and convert the Direct Current of the installed solar array into grid supportive AC power. Even though these inverters don’t have a number of components for failure, generation depends on the least generating module in the series. Due to shadow issues or low performing module of the whole series generation gets affected. This system best suits on the roofs where there are no shading issues due to trees, adjacent buildings etc.