Australia is known around the globe for its beautiful weather, which is often embedded in regional names such as Sunshine Coast. These denominations are finding a new truth these days as solar energy production grows. One out of four Australian households have installed solar panels. Many more wonder how they can tap into solar’s financial benefits. Adding a solar photovoltaic (PV) system to your home may be easier and less expensive than you think.
The core components of a residential solar PV system are panels and an inverter. Add a solar monitoring system to oversee your solar installation as well as wiring and mounting hardware. Battery storage may be needed if you want to be independent of the grid.
Let us give you the needed insights into the terminology and science behind solar, so you can confidently start shopping for the right components for your home.
On the Grid or Off?
Most homeowners already on an electric grid choose to continue doing so when installing solar. The convenience of knowing that you will always have power, even if your system should fail, is too great to cut the ties. The implications of going off the grid are multi-faceted. It would help if you had an extensive enough system to support your electricity needs, with fluctuations in production throughout the year. Plus, you will need battery storage to carry you through consumption peaks and days of low production.
Staying On the Grid – Grid-Tie Systems
Another significant advantage of staying on the grid is that if the local utility provider offers a net metering option, you can feed all your energy into the grid and be credited for it. This allows you to go with a much smaller system, netting your electricity consumption and production throughout the year. There is also no need for battery storage unless you prefer to have a backup for power outages.
Going Off the Grid – Letting Solar Power do all the Work
Many homes in rural areas are not on a reliable grid, and hooking them up is impossible. Some developments may require significant investments to bring the grid to the newly built or existing rural homes. There may be massive cost advantages to building a stand-alone system, offsetting the extra cost of added panels and battery storage. Or you might make a conscious choice to go off-grid to be less dependent on the electric network, to be self-sufficient. While it may be more expensive, the sense of independence could outweigh the costs.
The Best of Both Worlds, Hybrid Solar Systems
Increasingly often, homeowners are opting for a hybrid solar power system. These systems employ a smaller battery bank than an off-grid system. A smaller battery bank provides power at night or during electric grid outages to keep your home operating. You can maintain the convenience of a connection to the grid with the security of energy that you generate from your solar power system.
There are many solutions to a hybrid solar power system. Of note is the Tesla Powerwall. This integrated power storage solution from the Tesla corporation is a complete solution that needs only installation and connection to your solar panels and solar controller.
Components of a Residential Solar Power System
Whether grid-tied, off-grid or hybrid, let’s look at the various components of a residential solar system and their unique features.
Solar Panels – Turning Sunshine into Power
Sunshine is plentiful in our country and there for the taking. Solar panels with their photovoltaic cells are the key to converting sunlight to power. The cells absorb the sunlight and generate an electric current. This current is collected with each panel and then flows through the wiring into the inverter.
Solar panels come in different sizes, with the 60-cell panels being the most common. They usually measure around 170 x 100 cm in size. The most relevant feature of a solar panel is its power, denominated in watts (W). A lower end 60-cell panel will be in the area of 320 W, while high-efficiency panels will scratch the 400 W mark. When putting together your system, you might be looking at an affordable mid-range panel at 365 W. For a 5 KW system, you would need about 14 of those panels.
Solar Inverters – DC to AC
The electric flow that the panels produce is called direct current (DC). While DC can power certain appliances and produce light, most home electrical systems depend on alternating current (AC), which is also the “currency” of the electricity grid. The power from our solar panels needs to be converted from DC to AC to be usable in our home and fed into the grid. Voltage and frequency also need to be adjusted for that purpose. The device taking care of the conversion is called an inverter.
There is a variety of options when it comes to inverters. When installing a hybrid system, you will need a special hybrid inverter. Inverters for off-grid solutions are called standalone inverters. String Inverters are the most common for grid-tied residential applications.
Microinverters vs. Optimizers
Microinverters attach to each solar panel instead of using a centralised string inverter. This setup has advantages in settings with shading from trees and close-by buildings. The downside is that you must run AC wiring to each solar panel, and maintenance can be challenging due to the microinverters being located underneath the panels.
An alternative to microinverters is power optimisers, which also mount under each solar panel. However, they are smaller and less prone to needing maintenance. They connect to a regular string inverter. Because of the alignment of solar panels in a “string”, partial shading can cause whole system sections to go down, reducing energy production significantly. Both microinverters and optimisers have been developed to counteract the effects of shading and optimise energy production.
Solar Racking – Getting the Panels in the Sun
Even though more of an accessory, solar racking is worth a close look during the planning stage. There are multiple types of mounting hardware to attach the panels to your roof. The rack system is there to provide a stable platform for the solar panels. The racking will mount the panels parallel to the roof in most cases. However, there are various racking options to improve the angle of the panels toward the sun, helping to increase production. The extreme form is solar trackers that allow the panels to follow the sun on its journey across the sky.
Monitors and Management – Seeing What your Solar System is Producing
Time to have some fun with your system! After all the technicalities with wattage and installation, this is where you get to play. Monitoring your system via an interface is exciting because the functionality is visualised. Your monitor may be as simple as a panel on the inverter showing the current electricity production from your solar array. But in most cases, monitoring and management systems are available as sophisticated apps that track and display all the info you will ever want right on your smartphone.
Going Further – Off-Grid Equipment
Going off-grid takes the solar concept to the extreme. If you intend to minimise your dependence on the power grid or even cut ties completely, you must plan for additional equipment for your solar PV system. Your most significant add-on will be a battery backup. It will have to be capable of storing enough power when there is not enough or no sunlight to support your energy use. Knowing when your peak energy use is throughout the day and the seasons will go a long way with planning. You will have to determine how large your battery must be to cover your demand. The prices for batteries are comparably high. At roughly $1,000 per kWh, a 5kWh battery will cost you approx. $5,000.
Depending on your situation, you may also want to plan for a few additional panels compared to a grid-tied system. Expanding your capacity will better allow you to cover your usage in peak times and will increase production on gloomy days.
The excitement of going solar
Australia enjoys some of the best conditions globally to harvest solar energy. The prospect of tapping into the unlimited source of power is a fascinating concept. Reducing or eliminating the cost on your power bill is a prime motivator for many people. Installing solar is now more affordable than ever, and with financing and incentives available, it has become an absolute no-brainer.