Chapter 3

Introduction

With the rooftop array complete, the solar panels are capable of generating electricity whenever sunlight falls upon them. However, that electricity still has nowhere to go.

The DC cables produced by the solar array must now be connected to the inverter, integrated with the building's electrical system and safely linked to the electricity grid. Although much of this equipment is hidden from view once installation is complete, it forms the heart of every solar power system.

Careful positioning, neat cable routing and high-quality workmanship are just as important as the equipment itself. A poorly positioned inverter may overheat. Poorly routed cables may be damaged over time. Even something as simple as inaccessible equipment can make future maintenance unnecessarily difficult. 

For these reasons, installers don't simply connect components wherever space is available. Every location is chosen to balance safety, accessibility, protection from the environment and long-term reliability.

Choosing the Inverter Location

One of the first decisions is where the inverter should be installed. Although modern inverters are designed for outdoor use, they perform best when protected from excessive heat and direct sunlight.

A shaded wall with good natural airflow is often preferred, allowing the inverter to dissipate heat efficiently while remaining easily accessible for inspection and maintenance. The location should also minimise the distance between the solar array, the switchboard and any battery storage. Shorter cable runs generally reduce installation complexity while helping to minimise electrical losses. 

Engineers expect the system to operate for decades, so routine servicing and future replacement should be considered long before installation is complete.

Routing the Cables

With the equipment locations confirmed, installers begin routing the electrical cables throughout the system.

The DC cables travel from the rooftop solar array to the inverter using protected cable routes designed to minimise exposure to weather, ultraviolet radiation and accidental damage. Where cables pass through the building, suitable glands, conduits and protective sleeves help maintain the building's weather resistance while protecting the wiring itself.

Throughout the installation, cables are supported securely and routed neatly to prevent unnecessary movement or abrasion.

Professional installations are immediately recognisable by their tidy cable management. Well-organised wiring is easier to inspect, easier to maintain and less likely to develop faults over time.

Installing Protection Equipment

Before the system can be connected to the building, the necessary protection equipment must be installed. DC and AC isolators are positioned where they remain accessible for maintenance and emergency shutdown procedures. Protective devices such as circuit breakers and surge protection equipment are installed in accordance with local electrical regulations and the system design.

Rather than being added as an afterthought, these devices form an integral part of the installation. Their locations are carefully planned so that future inspection, testing and maintenance can be carried out safely. The objective is simple. If the system ever needs to be isolated or protected from abnormal electrical conditions, it should be possible to do so quickly and safely.

Connecting to the Switchboard

Once the inverter and protection equipment have been installed, the system can be connected to the property's electrical distribution system.

The AC output from the inverter is connected to the main switchboard through appropriately sized protective devices. This connection allows the electricity generated by the solar panels to supply household appliances while automatically exporting any surplus electricity to the grid. Throughout this stage, installers ensure that conductor sizes, protection devices and cable routes match the approved electrical design.

Every connection is checked carefully before the system is energised. Although these connections are rarely seen by the homeowner, they are among the most important in the entire installation.

Installing Battery Storage

If battery storage forms part of the project, it is usually installed alongside the inverter or in another suitable location specified by the manufacturer.

Because batteries are relatively heavy and sensitive to environmental conditions, installers carefully assess ventilation, structural support and accessibility before mounting the equipment. Communication cables, power cables and protective devices are then connected according to the manufacturer's requirements.

Even when a battery is not installed immediately, many modern systems are designed so that battery storage can be added later with minimal modification. Planning for future expansion during the initial installation often reduces both cost and complexity.

Earthing, Labelling and Final Wiring

As installation nears completion, the remaining electrical connections are finalised. 

The solar array, inverter and associated equipment are bonded to the building's earthing system to provide an effective fault current path and help protect both equipment and people. Permanent warning labels, safety notices and circuit identification markings are then installed throughout the system. These labels provide essential information for electricians, maintenance personnel and emergency services throughout the lifetime of the installation.

Finally, every cable termination is checked, every connector is tightened to the specified torque where required, and the completed wiring is inspected against the original design drawings. Only once these final checks have been completed is the installation considered ready for commissioning.

Looking Ahead

The rooftop array is now complete. The inverter has been installed. The electrical equipment has been connected. Every cable has been routed, protected and terminated.

Yet the system still hasn't produced a single kilowatt-hour of usable electricity. Before it can be switched on, every part of the installation must be tested to confirm that it has been built correctly and operates safely.

In the next chapter, we'll follow the commissioning process, discovering how professional installers inspect, test and verify every component before the solar power system is finally connected to the grid and handed over to its owner.