What Size Solar System Do I Need At Home?

When consumers start thinking about switching to solar, one of the first questions they ask is, “What size solar system do I need?”  

As per the Australian Energy Council Solar Report, the average size for a rooftop solar system is now 8kW. This sustainable model allows homeowners to become more energy efficient, not only cutting down energy bills but also CO2 emissions.

When deciding on solar panel sizing, here’s everything you need to know.

Table of Contents

How Many Panels Do You Need?

As per the Clean Energy Council report, the most common form of solar power installed in Australia is a grid-connected system. Standard solar panel models are now rated between 400W to 420W, though this varies from model to model.

Start by checking the wattage output rating to understand how much solar energy a panel can produce hourly. Simply multiply the solar panel output by the peak sun hours (400W (output) x 4.5 hours = 1,800 Watt-hours per day)

You can convert this value to the standard measurement of kWh by dividing it by 1,000 to find that one 400W panel can produce 1.8 kWh per day. Right after, gauge the solar system size by understanding how much solar power you’ll need on average.

Here’s what you need to consider for a residential solar panel:

  1. Average daylight energy needs daily
  2. Current electrical usage at home (in watts)
  3. Access to sunlight and roof space in your area
  4. Network distributor rules and regulations
  5. Efficiency of the solar panels you’re choosing
  6. Physical size and design of the solar PV systems

Analyse Your Electricity Bill and Consumption 

In an average Australian household, the energy consumption can generally amount to 15 to 25kWh, though this can vary from one household to another.

Electricity usage will also depend on the current season, so you may have to analyse your energy bills at different times of the year for a proper estimate. Study this data to get the average daily usage (appliances, air conditioning, and more).

Get in touch with your electricity retailer as they can give you a basic idea of your average daily consumption in kWh. It is important to have this value and your electricity bills in front of you when analysing your electrical usage.

Most energy companies may also outline a graph on the back of your bills that helps understand energy costs. But many factors will influence this value like the location and the amount of sunlight you receive yearly.

Address Your Daylight Energy Needs

Without access to a battery storage unit, your solar panel system is only resourceful when you use it during daylight hours. Regardless of this fact, it does reduce the amount of electricity you purchase from a retailer at a rate of 20-30 c/kWh.

Consider a solar panel system that generates enough electricity to facilitate your daytime needs. This can easily be done by estimating the percentage of your total electricity consumption when the sun is shining.

For instance, consuming 30kWh of electricity per day, but only using 1/3rd of that solar power during the day. In this case, we recommend a solar power system that generates 10kWh per day or you can find an accredited solar installer for precise estimates.

The primary goal is to find solar panel sizes that generate just enough energy to offset a major portion of your daytime energy needs without wasting the extra solar power.

Check the Roof Space in Your Home

Rooftops in Australia are designed differently for different homes, though there are certain parameters you can consider. Factors like the orientation of your roof, its angle or slope, overall space, shading, and roofing material can impact solar output.

For instance, installing a small-sized solar system on the available roof space can significantly impact your energy bills. Such solar systems may lack the ability to general excess solar energy, making you more reliant on electricity received from the grid.

The best way to design a self-sufficient solar panel system is by getting insights from a reliable solar retailer who can inspect your roof space. If your roof space is large enough to accommodate a bigger solar system, you can benefit from the feed-in tariff.

Study Your Time-of-Use Billing

One of the most important points to consider before installing solar panels is the time of use and the amount paid for that consumption. With time-of-use billing, you can clearly understand when energy usage is at its peak level. For panels facing west or north, the maximum output gained is in the afternoon, especially during summer.

Understand Network Distributor Rules

Network service providers across Australia provide specific guidelines to regulate solar energy production from your system to the grid. But these rules will vary from state to state, depending on the network service provider.

For instance, single-phase homes in South Australia can only export 5kW of solar power to the main electricity grid. This means they can install 13.3kW of solar panels on their rooftops, though they’re allowed to oversize their panels by 33%.

In NSW, you have to take permission from the electricity distribution network provider prior to the solar installation. Additionally, the wiring and installation can only be conducted by a licensed contractor or a qualified supervisor.

Should You Invest in Battery Storage?

Not all solar panel systems come with battery storage. Such battery units may be sold separately or built into an existing solar system. The biggest benefit of a solar battery is that it isn’t dependent on how many solar panels you have installed.

But the type and kind of battery storage you install do rely on your end goals. For instance, a small home that receives little sunlight can opt for a solar battery to power appliances at night or during the day.

How Much Electricity is Part of Your Base Load?

Every household has a base electricity limit.

This consumption includes electrical appliances like lighting, fridge, air conditioner or heater, hot water systems and more. It’s important you understand your base load for appliances that are mostly on standby to determine the right solar panel size.

You should also keep in mind that electrical consumption increases during weekends and the holiday season. To find the right dimensions of a solar panel, get in touch with experts who can help you minimise energy costs.

What Impacts the Output of a Solar Power System?

The output of any solar panel system is also influenced by your roof’s orientation. So, if you want to maximise solar electricity, consider the following.

  • Smaller homes can explore a split solar array that helps increase the voltage by splitting the size of the silicon chips.
  • Panels facing east can get more solar power in the morning versus west-facing panels that output more power at noon.
  • Install two strings of solar panels to create smaller peaks for easier access to solar power during daylight hours.

What Size Solar System Do You Need? Ask the Experts at HCB Solar!

If you’re looking for reliable residential solar panel manufacturers in Newcastle, our experts can guide you every step of the way.   

Depending on your property, HCB Solar can help you find a suitable solar panel system for your home. Our dedicated local team will examine your property and provide solutions to maximise solar efficiency.

Contact us today!

Key Takeaways

Related Articles