Homeowners thinking about going solar have a lot of questions - which they should, considering the sizeable price tags of solar power systems. One of the most common questions is ‘how much do solar panels cost for a three bedroom house?’
And although this question sounds simple, it does not have a straightforward answer, because this is similar to asking the price of a 5-seater car. So the short answer to this question is (you guessed it right) - ‘It depends’.
However, given the frequency of the query, we decided to dive in a little deeper, and create a longer, more detailed answer that would finally feel more like an answer. So here we go.
The size (and cost) of a solar power system is governed primarily by the energy consumed, and not the size of the house. The reason solar costs can vary for different 3-bedroom houses is that they can use different amounts of energy. A minimalist may have just 10 appliances powering their house, while another family in a similar 3-bedroom house may have 50 appliances.
However, we can dig out the average energy consumption for such a house, and then look at the cost of a system needed for an average house. But before going to the cost portion, let us talk about the size of solar needed for a typical 3-bedroom house.
How Many Solar Panels Do You Need for a Three Bedroom House?
The average Kiwi home in 2022 was 147 sq. m., which is the typical area of a 3-bedroom house. The average energy consumption (now we get closer to the answer!) of such an average house is 8,492 kWh per year.
The above value is what solar panel installers ultimately use to decide the size and cost of a system. Let us do that here.
On average, New Zealand receives about 2,000 hours of full sunshine in a year. An easy way to find out the system size is as shown below:
8,492 kWh ÷ 2,000 h = 4.24 kW
Add a little more to that considering the power losses, and we can say that ‘a typical, 3-bedroom house in New Zealand requires about 5 kW of solar panels.’
Factors Affecting the Size of a Solar Power System
While it is true that a 5 kW system would suffice most 3-bedroom homes, these are average numbers. And there is a wise saying about averages - ‘On average, nothing is average’. In other words, not all homes will need the exact 5 kW system mentioned above. There are several factors at play that decide how big your system should be.
Energy consumptionThe most important factor, obviously, is your annual energy consumption. A house that consumes 10,000 kWh per year will need twice the panels of a home consuming just 5,000 kWh.
LocationWhile energy consumption is the primary factor, even homes with identical energy consumptions can need different system sizes. The 2,000 sunshine hours we discussed above are also an average number.
A home located in Auckland will receive over 2,050 sunny hours each year, but a similar home in Dunedin will receive only 1,600 sunny hours. Naturally, the Dunedin home will need more solar panels to maximize the power generation.
Roof orientationAlthough locations may affect system sizing, sometimes even two identical homes across the street may need different system sizes. In New Zealand, north-facing roofs are best suited for solar, and not all homes are designed that way.
When such a roof orientation is not available, systems can be installed on east or west-facing roofs. However, since the output of such systems will be notably lower, you will need more panels to compensate for the lower performance.
Let us now move to the cost question.
What is the Cost of a 5 kW Solar Power System?
The average 5 kW solar panel system costs about $13,500 - this includes the cost of consultation, equipment, transport, paperwork, and installation. When you consider the pricing per watt of a system ($/W), solar energy system costs generally decrease with increasing system size. For instance, a 2 kW system will have a higher $/W pricing than a 5 kW system.
Besides the size, there are a few other factors that decide the cost of solar panel systems. Here is a list:
InstallerDifferent solar companies may quote a different price for the same solar power system. More experienced installers may charge more, while sometimes newer installers may offer low pricing to attract more customers. Overall, it is always best to get quotes from more than one installer.
My Solar Quotes allows you to get free quotes from multiple installers, which you can compare on parameters such as price, warranties, equipment offered, etc.
Equipment QualityJust as two 5-seater cars can have entirely different performance abilities, two different solar panels can have different power ratings despite their similar looks. High quality solar panels boast high efficiency, which means you can generate more power in fewer solar panels.
Similarly, good-quality inverters also have higher efficiencies. Higher quality solar equipment generally has longer lifespans. Some solar panels come with a 10-year product warranty, while the best ones can have a 25-year term. Similarly, inverters and batteries can have warranties ranging from 5 to 15 years.
Better equipment means slightly higher pricing. That said, in most cases, the extra cost of premium equipment is often worth it, as it saves a lot more money over its long life.
System FeaturesModern solar equipment offers a ton of features. For instance, you can choose to go with microinverters instead of a single, centralized inverter. Microinverters convert power at the level of each solar panel, and are proven to improve performance and monitoring capabilities.
Or you can choose to go with a traditional setup but add power optimizers to improve performance and monitoring without spending too much.
Some homeowners choose to spend a little extra not on the performance but on the aesthetics. For instance, many companies offer all-black, sleek solar panels that blend well with the roof without standing out.
ComplexityThough not a frequent factor, the complexity of a system may increase the cost of a system. For example, roof-mounted and ground-mounted solar panels have different costs. Even among roof-mounted panels, inclined and flat-mounted panels have different pricing.
Panels installed on a patio or a solar carport will also have pricing that is different from traditional, roof mounted panels.
It is a little difficult to say how much solar would cost for a three-bedroom, or a four-person house. The more important metric is how much energy such a house uses. However, based on some average data, we can find an average system size, which comes to about 5 kW.
A 5 kW system can cost anywhere between $11,000 and $15,000 on parameters such as the installation company, type and quality of equipment, and so on. The most important thing to remember, however, is this - buying a solar power system for a three bedroom house (or any house, for that matter), is one of the best financial decisions you will ever make!