Grid-tied systems are the most common type of solar PV system. Grid-tied systems are connected to the electrical grid, and allow residents of a building to use solar energy as well as electricity from the grid. Grid-tied systems do not need to produce 100% of the electricity demand for a home or business. When there is no demand for energy, the solar panels send excess electricity back out into the grid for use elsewhere. When a home or business is using energy, but the solar panels aren’t producing enough energy (at night, or on a stormy day), electricity from the grid supplements or replaces electricity from the panels.
Owners of a grid-tied system complete a net metering agreement with their utility. This agreement allows utility customers to receive credit for the excess energy they generate, typically credited as a kilowatt-hour credit on the next month’s bill. Net metering policies and agreements are different for each utility. Living with a grid-tied solar PV system is no different than living with utility electricity, except that some or all of the electricity you use comes from the sun. Grid-tied systems do not provide protection from power outages. When the electrical grid fails, grid-tied systems will not continue to operate. This allows utility employees to fix the power lines safely without wasting time identifying solar energy systems that are still feeding electricity into the power lines.
- PV panels, which cost anywhere from Rs. 35 per watt to over Rs. 50 per watt, are the single biggest expense of a PV system. Their placement and mounting affect your system performance more than any other facet of the job.
- Mounting your PV panels is of critical importance. First, you need to mount the panels where they’ll get maximum sunshine over the course of a year. But the more difficult problem is to mount them with enough integrity that they’ll stay put for 25 years or more.
- Inverters take the low-voltage, high-current signals from the PV panels and convert them into 120VAC (or 240 VAC), which is directly compatible with grid power. Inverters cost around Rs. 45 per watt, or around Rs.2,00,000 for a typical application. From a reliability standpoint, they are generally the weak link in any PV system, so quality is a must.
- Tracking mounts mechanically move the PV panels over the course of a day so that they directly face the sun at all times. Dual axis trackers change both azimuth and elevation, while single axis trackers only match the azimuth.
- Disconnect switches are of critical importance, and they need to be mounted within easy reach. Every member of your family should know exactly how to turn the PV system off for safety reasons. If any abnormal behavior occurs in your home’s electrical system, shut off the solar system first.
Wiring and Fuse Box Connections
- Wiring, conduit, and connections to your household main fuse box are minor hardware expenses, but they comprise a big chunk of the labor when you’re installing a PV system.
- To make system active by provide battery backup when On-Grid solar system is OFF. This backup can be design up to requirement and few hour to 24 hours. This battery bank charge by charger & controller and discharge by inverter provided in this system.
Utility Power Meters
- Conventional power meters are capable of spinning backward, but utility companies usually change to a special digital meter when you connect to the grid because most solar customers go to the TOU (time-of-use) rate structure, which requires more intelligent processing than a mechanical device is capable of.