Solar Energy System “On-Grid System”

 

All solar energy systems work on the same basic principles. Solar panels first convert solar energy or sunlight into DC power using what is known as the photovoltaic (PV) effect. The DC power can then be stored in a battery or converted to AC power by a solar inverter which can be used to run household appliances. Depending on the type of system, excess solar energy can either be fed into the electricity grid for credit, or stored in various battery storage systems. Here in this post, we are going to discuss on-grid solar panels.

Grid-tie solar or Solar on grid systems are by far the most common and widely used by homes and businesses. These systems do not require batteries and use solar inverters or micro-inverters and are connected to the public electricity grid. Any excess solar energy you produce is exported to the electricity grid and you are usually paid a feed-in-tariff (FiT) or credit for the energy you export.

Unlike hybrid systems, on-grid solar systems are not able to operate or generate electricity during blackouts for safety reasons. Since blackouts usually occur when the power grid is damaged; If the solar inverter was still supplying power to the damaged grid, it would pose a safety hazard to those repairing the fault in the network. Most hybrid solar systems with battery storage are capable of automatically isolating themselves from the grid (known as islanding) and continue to supply some power during a blackout.

Batteries can be integrated into the on-grid system at a later stage if required. The Tesla Powerwall 2 is a popular AC battery system that can be integrated into an existing solar system.

In an on-grid system, after the electricity reaches the switchboard:

Metering Excess solar energy flows through the meter, which calculates how much electricity you are exporting or importing (buying).

Metering systems work differently in many states and countries around the world. In this description, I am assuming that the meter is only measuring electricity being exported to the grid, as is the case in most of Australia. In some states, meters measure all the solar energy your system produces, so your power will run before your meter reaches the switchboard and not after. In some areas (currently in California), the meter measures both production and export, and the consumer is charged (or credited) for the net electricity used over a month or year. Electricity sent to the grid from your solar system can be used by other consumers on the grid (your neighbors). When your solar system is not working, or you are using more electricity than your system, you will start importing or consuming electricity from the grid solar system.