How Many Solar Panels Are Needed to Run a House?


The shift towards renewable energy sources is gaining momentum in the South West, Western Australia (WA), with many homeowners considering solar power as a sustainable and cost-effective solution. The appeal of solar energy lies in its ability to reduce electricity bills and contribute to a cleaner environment. 

Let’s explore the essentials of solar panel installation, including how to determine your solar needs and the factors influencing system efficiency.

Determining Your Solar Needs

The first step is assessing your household’s energy consumption. The number of solar panels required depends on your home’s size and energy usage. 

A typical home in South West WA with moderate electricity usage runs an air conditioner, a refrigerator, a washing machine, and other common appliances; totalling about 20kWh of energy per day. 

This means a solar system with a capacity of around 5kW is the ideal choice, translating to roughly 15-20 solar panels.

However, specific needs vary based on lifestyle and energy habits.

Solar Panel Calculations

To accurately determine the number of solar panels needed for your home, consider the following factors:

Monthly Energy Usage: Review your electricity bills to find out your monthly energy consumption. For example, if your home uses 1000 kWh per month, this figure is crucial for the calculation.

Panel Wattage: The output of each solar panel, typically around 300 watts for residential panels, affects the total number of panels needed.

Solar Irradiance: Consider the average sunlight your location receives, as solar panel output depends on the intensity of the sun, known as solar irradiance.

Peak Sun Hours: In South West WA, the specific peak sun hours—the time during which the sun’s intensity is at its maximum—will impact the energy production of your solar panels.

Example Calculation

Total Wattage Needed: For a home consuming 1000 kWh per month, you need enough panels to produce this amount of energy.

Monthly kW Hours: 1000 kWh divided by the average 30 days in a month equals approximately 33.33 kWh per day.

Panel Requirement: Assuming each panel produces 300 watts, calculate the total number of panels by dividing the daily kWh requirement by the individual panel’s output, adjusted for peak sun hours.

If you get 5 peak sun hours per day, a single 300-watt panel produces 1.5 kWh per day (300 watts * 5 hours).

Therefore, 33.33 kWh daily need / 1.5 kWh per panel = around 22 panels.

Other Factors Affecting Solar Panel Efficiency

The efficiency of solar panels is affected by several factors, including:

Geographical Location: South West WA experiences varying sun hours, which affect solar energy generation.

Roof Space and Orientation: Optimal panel placement and orientation maximise sunlight exposure, enhancing energy production.

Weather Conditions: Seasonal weather changes can influence solar panel output, necessitating a system design that accommodates these variations.

Solar System Sizing

Choosing the optimal size for your solar system is crucial to ensure it’s neither too large, creating surplus energy, nor too small, failing to meet your energy needs. In South West WA, where sunlight and weather conditions are favourable, system sizes typically range from 3kW to 10kW. 

By examining peak sun hours and historical energy usage, homeowners can select a system that precisely matches their consumption patterns, ensuring efficient and adequate power supply.

Installation and Maintenance

To reap the full benefits of solar energy, professional installation and regular maintenance are essential. A correctly installed system, with panels strategically placed for optimal sun exposure, can significantly increase efficiency. 

Regular cleaning and routine inspections help maintain performance and prolong the lifespan of the solar setup, ensuring it continues to meet your energy needs effectively.

While the upfront cost of solar installation may seem daunting, the long-term savings on utility bills and the availability of government incentives make it a financially sound choice. 

As a leading solar solutions provider, Zenko Energy is committed to helping homeowners in South West WA transition to renewable energy seamlessly and efficiently. With expert guidance and quality installations, we ensure each solar system meets your home’s unique needs. To know more about how you can benefit from our solar panel installation, connect with us today.