Grid-tied systems

These are connected to the City’s electricity grid either directly or through your property’s internal wiring. There are two types of grid-tied systems.

• Grid-tied feed-in system (also known as an EG with export option): the electricity generated by the PV system is used on the property. Excess electricity generated from the system is fed back into the electricity grid – you may receive credit from the City.
• Grid-tied non-feed-in PV (also known as an EG with no export option, with reverse power flow blocking): the electricity generated by the PV system is used on the property only when there is a demand for it. Excess electricity generated is blocked from feeding back into the grid.

Grid-tied hybrid systems

Grid-tied systems that island after interruption of the distributor supply or when the applicable electrical service conditions are outside stated limits or out of required tolerances and then supplies the load from the inverter, operating in the stored-energy mode via a suitably interlocked change-over switch.

How Grid-tied solar power works

A grid-tied solar power system operates by harnessing solar energy and converting it into electricity, which is then fed into the local power grid. Here’s a basic overview of how such a system works:

1. Solar Panels (Photovoltaic Modules): The system begins with solar panels, also known as photovoltaic (PV) modules, installed on the roof or in an open area. These panels are made up of solar cells that convert sunlight into direct current (DC) electricity.
2. Inverter: The DC electricity generated by the solar panels is then sent to an inverter. The inverter’s primary function is to convert DC electricity into alternating current (AC), which is the type of electricity used in homes and businesses.
3. Electricity Production: The AC electricity produced by the inverter can be used to power appliances and devices within the premises where the solar panels are installed. Any excess electricity not used on-site is then directed to the grid.
4. Net Metering: In a grid-tied system, a net meter is installed to measure the amount of electricity produced by the solar panels and the amount of electricity consumed from the grid. If the solar panels generate more electricity than is being used on-site, the excess is fed back into the grid, and the meter runs backward. Conversely, if the electricity demand exceeds what the solar panels are producing, electricity is drawn from the grid.
5. Connection to the Grid: The solar power system is connected to the local electricity grid. This connection allows for the seamless exchange of electricity between the solar system and the grid.
6. Credit or Compensation: In many regions, including South Africa, there are policies in place for net metering or feed-in tariffs. This means that when the solar system produces more electricity than is consumed on-site, the excess is fed back into the grid, and the system owner receives credit or compensation for that contribution.
7. Utility Integration: The electricity grid acts as a virtual battery, allowing surplus electricity generated during sunny periods to be supplied to the grid, and the user can draw power from the grid when solar production is low, such as at night or on cloudy days.
8. Monitoring and Maintenance: A grid-tied solar system often includes monitoring tools that allow users to track their energy production and consumption. Regular maintenance ensures the system operates efficiently over time.

It’s important to note that specific regulations, policies, and incentives related to solar power can vary by region and may change over time. Therefore, it’s advisable to consult with local authorities or solar energy professionals to understand the specific details and requirements in South Africa.