Can Enough Solar Power Be Generated To Power A Home?

Written by Aniket Bhor
Last updated: 15th September 2026

Yes, it is possible to generate enough solar power to power a home in New Zealand. The amount of solar power that can be generated depends on several factors such as the size and orientation of the solar panels, the efficiency of the panels, the local weather conditions, and the electricity consumption of the home.

New Zealand has excess amounts of sunlight, more than enough to power the entire country with solar energy. NIWA scientists provide ample evidence to support this claim, stating that “The solar energy arriving at the roofs of New Zealand homes over the course of a year is twice the country’s total annual energy consumption, or 16 times the energy used in those homes.”

The Different Regions of New Zealand And Potential Solar Power Production

In New Zealand, electricity production via solar power systems varies from region to region. This can be dependent on:

• Latitude (locations located closer to the equator will generate more solar power)
• The amount of cloud cover a region/area experiences

NIWA has taken multiple years of weather data and estimated the solar energy we have available around New Zealand. NIWA’s solar radiation map (seen below) displays areas that experience the greatest amount of sunlight in a given day. Locations with a higher proportion of clear-sky days, such as Nelson, Blenheim, Manawatu, Bay of Plenty, and Hawke’s Bay, correspond with higher solar irradiance.

Resource from NIWA Science

New Zealand’s Potential Solar Compared To The Rest Of The World

There’s no doubt about it – all areas of New Zealand are worthy of having a solar power system installed. Sure, some NZ regions like Invercargill receive lower amounts of solar radiation in comparison to others; however, Invercargill gets more sun than Germany, which has one of the highest rates of solar power per capita in the world.

Annual Solar Generation for Different Sized Systems in Different NZ Cities/Regions

The easiest way to understand solar potential in a city is not to look at the technical jargon of solar irradiation or insolation. Instead, looking at how much energy a typically sized system will generate in a particular city gives an excellent idea of how effective solar in that city is.

What follows is an overview of the potential impact of a residential solar power system in all major cities of New Zealand. We referred to Global Solar Atlas to find peak sunshine hours in each city/region, and used Branz’s photovoltaic generation calculator (assuming a 20° tilt) to find out solar generation values from five common system sizes (3 kW to 10 kW) on a typical home in every major NZ city/region.

Auckland Solar Generation

Despite Auckland’s reputation for wet winters, it receives plenty of sunshine, clocking in an impressive 1460.1 peak sunshine hours in an average year (about 4 hours per day, on average).

This translates to 7,145 kWh of power generated per year with a typical 6 kW system. Considering an average electricity cost of 40 cents/kWh, a system cost of $12,000, and 50% self-consumption, you can expect a payback period of around 6.45 years.

Such strong numbers mean installing solar panels on your Auckland home is a highly viable option. Below is a table showing energy generation values for four other common sizes in Auckland.

Auckland Seasonal Variation

Solar generation peaks in summer (October–March) when days are longer and skies clearer. Winter generation (April–September) drops approximately 35–45% due to shorter days and increased cloud cover.

For a 6 kW system in Auckland:

• Summer (6 months): ~4,287 kWh
• Winter (6 months): ~2,858 kWh

This seasonal shift is important for battery planning. Households relying on solar alone during winter may need battery storage for nighttime independence.

Wellington Solar Generation

On average, Wellington receives 1398.7 peak sunshine hours every year (3.83 hours per day). While that number is a good reason for installing solar in Wellington, there’s another major advantage of going solar in ‘Windy Welly’. Wellington’s famed gales help boost solar generation by blowing off dust from the panel surface and also keeping them cool during hotter days, acting as a natural, free-of-charge maintenance system.

For a 6 kW system, you can expect to receive 6,993 kWh of energy each year. This energy can help you recover your system’s cost in 6.6 years, assuming the same average system and power pricing as earlier. A residential system with a 6.6-year payback is certainly worth the investment.

Here’s a table for Wellington with energy yield values for the other four system sizes:

Wellington Seasonal Variation

The summer months of October to March see higher generation in Wellington, thanks to longer days and clearer skies. Winter generation (April–September) drops approximately 40–50% due to shorter days and increased cloud cover.

For a 6 kW system in Wellington:

• Summer (6 months): ~4,336 kWh
• Winter (6 months): ~2,657 kWh

Lower generation in winters means some homes may need to use batteries for optimum consumption of their solar energy.

Christchurch Solar Generation

Christchurch is blessed with a drier, sunnier climate, compared to its rainier counterparts on the West Coast. Christchurch’s 1394.9 peak sunshine hours (3.8 per day) can help you generate 6,707 kWh of solar energy in an average year.

Considering all the previously assumed parameters to be constant, an annual yield of 6,707 kWh can lead to a payback period of 6.88 years. Looking at the energy and payback numbers, it’s safe to say that Christchurch is a great place to install a solar panel system. Take a look at the approximate energy generation values for other common sizes in Christchurch:

Christchurch Seasonal Variation

Summer in Christchurch (October–March) has shorter nights and low cloud cover, allowing higher generation. Winter (April–September) leads to shorter, cloudier days, reducing the generation by approximately 45–55%.

For a 6 kW system in Christchurch:

• Summer (6 months): ~4,292 kWh
• Winter (6 months): ~2,415 kWh

Since solar generation nearly halves in winter, families who don’t want to rely too much on grid power may need to install a battery.

Dunedin Solar Generation

Being farther South, Dunedin’s shorter winter days mean a dip in generation in winter months. However, with 1200.8 peak sunshine hours (3.29 per day), it is not too far behind the likes of Auckland or Wellington. Moreover, its proximity to the pole means much longer summer days and therefore significantly higher energy yields in the summer months.

Assuming the other parameters are the same as for our other cities, Dunedin’s residents can enjoy 5,792 kWh of energy annually with a 6 kW system. This would mean a payback period of just under eight years, which still gives you almost two decades of free solar power – definitely a sound investment!

The following is the table for Dunedin’s energy generation values for 3, 5, 8 and 10 kW systems:

Dunedin Seasonal Variation

Dunedin also sees higher generation in summer (October–March) because of bluer skies and more suitable sun angles. Winter generation (April–September) drops approximately 50–60% due to shorter days and lower sun angles.

For a 6 kW system in Dunedin:

• Summer (6 months): ~3,823 kWh
• Winter (6 months): ~1,969 kWh

Dunedin homes may find 1,969 kWh insufficient for their needs in winters, and may have to rely more on grid power or install a battery system.

Nelson Solar Generation

With a staggering 1526.3 peak sunshine hours (4.18 per day), Nelson is an absolute powerhouse for solar energy. Depending on some sources, Nelson is the sunniest city in the country (a pun-lover might even use the joke Nel’sun’ here). Nelson’s unique geographical position means it enjoys a microclimate that makes it highly suitable for solar power.

If you put a 6 kW system on your house in Nelson, you can get a superb 7,729 kWh of solar energy annually. Assuming all other parameters remain the same as in our other cities, you can see a payback of under six years with this level of energy generation. Obviously, getting a solar energy system in Nelson then becomes a no-brainer. Check out the energy generation values for some other system sizes below:

Nelson Seasonal Variation

Nelson’s seasonal variation is not drastic, but its generation does peak in summer (October–March), due to longer days and unobstructed skies. Winter generation in Nelson (April–September) drops approximately 35–45% due to shorter days and overcast conditions.

For a 6 kW system in Nelson:

• Summer (6 months): ~4,715 kWh
• Winter (6 months): ~3,014 kWh

A solar battery may not be essential in Nelson homes with solar power, but homes that want to maximise self-consumption in winter may choose to install a battery.

Bay of Plenty Solar Generation

With 1562.4 peak sunshine hours (4.28 PSH per day on average) in an average year, I’m tempted to call it ‘Bay of Plenty of Sunshine’. For a typical 6 kW solar energy system, a household in the Bay of Plenty region can expect around 6,878 kWh of energy annually, which is more or less an average Kiwi home’s electricity usage.

Considering the system pricing, tilt angle, and other variables are the same as earlier sections, the 6 kW system can pay itself off in just 6.71 years. Overall, despite Bay of Plenty’s coastal, somewhat rainy climate, its solid sunshine numbers make solar power totally worthwhile in the region.

Here’s a table for Bay of Plenty’s energy generation values for our usual four system sizes:

Bay of Plenty Seasonal Variation

The sunny summer months (October to March) naturally deliver the highest energy yields. When winter arrives (April to September), reduced daylight and slightly more cloud cover pull production down by approximately 30–35%.

For a 6 kW system in Bay of Plenty:

• Summer (6 months): ~4,127 kWh
• Winter (6 months): ~2,751 kWh

To combat the 30–35% reduction in energy yield and keep the lights on without grid power during winter nights, integrating battery storage is a highly effective strategy.

Hawke’s Bay Solar Generation

Hawke’s Bay may be famous for its wine, but don’t underestimate its sunshine. It receives an admirable 1487.5 peak sunlight hours (4.07 per day) every year, thanks to consistently clear skies. That’s not all – Hawke’s Bay’s mild, non-extreme year-round temperatures mean your solar panels will not degrade fast, resulting in higher yields over the system’s lifespan.

In terms of energy yield, a home in, say, Napier, can generate about 7,383 kWh of energy per year. A quick calculation tells us that this can result in a handsome payback period of just 6.25 years.

Here’s a table showing energy generation numbers for four other system sizes between 3 kW and 10 kW:

Hawke’s Bay Seasonal Variation

Similar to most other cities, Hawke’s Bay also sees peak solar production between October and March when the sun is high and the skies are mostly clear. During the April–September window, generation decreases by around 35–40% due to the natural shortening of the days.

For a 6 kW system in Hawke’s Bay:

• Summer (6 months): ~4,504 kWh
• Winter (6 months): ~2,879 kWh

For complete nighttime reliance on your own solar energy during the colder months, a battery system is not mandatory but certainly a wise choice.

Manawatū Solar Generation

Although Manawatū’s temperate climate sees cloud bands rolling periodically, the region still gets enough reliable sunshine to make solar a good choice. It receives 1384.4 peak sunshine hours (3.8 per day) annually, which means an energy generation of 6,830 kWh/year.

For a typical house in one of Manawatū’s communities, like Palmerston North, a 6 kW system with the above-mentioned solar generation will have a payback period of around 6.76 years. Manawatū’s winds may not be as powerful as Wellington’s, but they are strong enough to keep the panels cool and relatively clean.

For a sub-7-year payback, going solar in Manawatū is certainly worthwhile. Below is a table showing energy generation for the four common sizes:

Manawatū Seasonal Variation

Manawatū’s nearly 1,700 kWh difference between summer (October–March) and winter months (April–September) can be attributed to shorter days and more cloud cover in the winter months.

For a 6 kW system in Manawatū:

• Summer (6 months): ~4,235 kWh
• Winter (6 months): ~2,595 kWh

The clear difference between summer and winter generation means homes may need to spend more on grid power in winters. Alternatively, they can choose to install a solar battery to store solar power and increase self-consumption.

Northland Solar Generation

Northland, New Zealand’s northernmost region – often referred to as the ‘winterless North’ – receives 1442.5 peak sunshine hours every year (3.95 daily). These sunny hours are enough to cover a significant portion of your home’s energy needs. Thanks to its relatively brighter winters, the seasonal gap in energy generation is also smaller in Northland than in most southern regions.

Based on the irradiation data, a 6 kW, north-facing system with a 20-degree tilt in a Northland city like Whangārei can generate 6,924 kWh/year. In financial language, this means your system is paid off in 6.7 years, which makes the purchase a lucrative option over the more expensive grid power.

Here’s a table with solar generation values for some common system sizes in Northland:

Northland Seasonal Variation

Northland experiences a similar pattern for energy generation between summers (October–March) and winters (April–September). Winter generation sees an approximately 30–40% drop due to shorter days and increased cloud cover.

For a 6 kW system in Northland:

• Summer (6 months): ~4,016 kWh
• Winter (6 months): ~2,908 kWh

Northland families planning to go solar may need to install a system based on this winter generation and will also benefit from a battery installation.

Waikato Solar Generation

Waikato’s warm days and cool nights are a perfect combination for solar panels, especially when you consider its 1448.8 annual peak sunshine hours (about 3.97 per day). Although morning fog and occasional rain in Waikato can reduce solar generation, the region has the potential to generate around 6,969 kWh of energy from a typical 6 kW rooftop system.

Whether you live in Hamilton or other towns, solar energy makes perfect sense for your home, especially considering the short estimated payback period of 6.62 years.

Take a look at the energy generation values of different systems in Waikato; note how they are not drastically lower than the sunniest of cities like Nelson.

Waikato Seasonal Variation

Waikato homes experience an approximately 35–45% difference in summer (October–March) and winter (April–September) solar generation values. While clear skies in summer offer maximum generation, winter fog and longer nights reduce the generation to less than 3,000 kWh.

For a 6 kW system in Waikato:

• Summer (6 months): ~4,181 kWh
• Winter (6 months): ~2,788 kWh

Similar to other cities, Waikato homes that rely fully on solar may benefit from a solar battery to maximise their self-consumption.

Taranaki Solar Generation

The number of peak sunshine hours in the Taranaki region may vary with the exact location, but lies anywhere between 1400 and 1500 hours/year (3.8–4.1 per day). If we look at New Plymouth, the largest city and population centre in Taranaki, the peak sunshine hours quite impressively reach 1479.5 annually.

Based on that number, if you install a 6 kW system on your New Plymouth home, you can generate a substantial 7,472 kWh/year. This results in a relatively short payback period of 6.18 years. It is no surprise, therefore, that the adoption of solar power is surging in Taranaki. Check out the table below showing generation values for four other common system sizes.

Taranaki Seasonal Variation

Of Taranaki’s annual solar generation potential, the winter months of April to September receive only 40%. Summer months (October–March), on the other hand, get 60% of the annual yield.

For a 6 kW system in Taranaki:

• Summer (6 months): ~4,558 kWh
• Winter (6 months): ~2,914 kWh

These numbers suggest that homes may have higher energy bills in winter even with a solar power system. To counter this, Taranaki homes can choose a battery system to improve self-consumption and reduce bills.

Southland Solar Generation

Too often, we think of rain, wind and cold when thinking about Southland or Invercargill, but it is important to remember that Invercargill is called the ‘City of Water and Light’, and the ‘light’ part is just as important as water. Thanks to its position in the deep South, Southland has incredibly long and bright summer days, which compensate for the darker and wetter winter days.

Look at the numbers – Invercargill receives 1205.8 peak sunshine hours every year (3.3 per day). It’s lower than most Northern cities, but it’s still higher than Germany, which is one of the global leaders in solar. A 6 kW system in Southland can generate about 5,787 kWh/year, and promises a payback period of 7.98 years, which makes solar a wise choice. Here’s a table with solar generation values for the four other common system sizes:

Invercargill Seasonal Variation

Southland is notorious for darker winters, and that is visible in the difference between the summer and winter generations, which has a factor of about 2.

For a 6 kW system in Invercargill:

• Summer (6 months): ~3,877 kWh
• Winter (6 months): ~1,910 kWh

Since sunshine is scarce in winters, a solar battery system and a slightly overdesigned array can mean greater independence from the power grid and lower bills.

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How Roof Orientation Affects Solar Generation in NZ Regions

How much solar power your home can get from a set of panels depends on numerous things, and sunshine hours are just one variable of the bigger equation. Your roof’s orientation and pitch can also have a notable effect on the energy generation from your system.

All the values in the previous section assume a North-facing roof with a 20° pitch. Theoretically, the most ideal tilt angle for solar panels is the latitude of that location. For example, Auckland lies at a latitude angle of 36.85°; this means solar panels installed at this angle and facing north (because Auckland is in the Southern Hemisphere and sunrays strike it from the north) will generate the highest amount of energy.

However, most roofs in NZ have a pitch ranging from 20° to 35°. If an Auckland home has a 25° roof pitch, installing panels at a 36.85° angle requires more complex mounting structures than just laying the panels flat against the roof. The additional cost and complexity of such installations mean the hassle is not worth it.

Most installers will prefer to install panels with the existing roof angle, unless the roof angle is too far from ideal. In certain cases, installers can also install panels horizontally on a flat roof, which has its own pros and cons.

What If You Don’t Have a North-Facing Roof?

Although the southwards path of sunrays makes north-facing panels ideal, it does not mean other roof orientations aren’t fit for a solar installation. Installing panels on east- or west-facing roofs is a common technique. In fact, east- or west-facing panels can generate more power than north-facing panels during early mornings (east-facing) or late afternoons (west-facing).

Overall, panels installed facing the East or West generate about 20% less energy (also varies based on tilt angle), which is definitely not a deal-breaker!

Unfortunately, this does not apply to south-facing panels. While installers in the Northern Hemisphere jump with joy seeing a south-facing roof, installers in New Zealand will just shake their heads.

South-facing roofs receive the least direct sunshine, and depending on the pitch, the drop in solar generation can be up to 50%. This means you’ll either need a system that’s twice as large as a north-facing roof, or be content with half the savings and about twice the payback period.

Which Region in NZ Has the Best Solar Energy Generation

Since New Zealand stretches North to South from a latitude of 34° to 47°, the amount of sunshine received, the length of days in each region, and subsequently the solar energy generation will vary significantly.

Below is a table that shows the annual energy generation of each region, categorised into three tiers – tier 1 includes the highest-generation cities/regions while tier 3 has the lowest-generation cities.

You may look at the difference between the Tier 1 and Tier 3 cities and wonder if solar is worth it in Tier 3 cities. Here, it’s important to note that the generation values of Tier 3 cities look low only relative to Tier 1 NZ cities. These generation values are objectively decent and make solar a perfectly worthwhile investment even in Southland and Dunedin.

How New Zealand’s Solar Potential Compares to Other Countries

More often than not, notions about a country or region’s solar potential can affect whether homeowners see solar as an effective investment. New Zealand may not be on top of the “sunniest countries” list, but it has enough sunshine to make solar a worthwhile choice anywhere in it.

In fact, NZ has more sunshine than some countries with a higher level of solar adoption than us. For instance, Germany, one of the top countries for installed solar energy, has an average solar potential that’s lower than Dunedin, one of our lower-solar-potential cities.

Here’s a list of the top solar-adopting countries, their average solar potential, and how NZ compares to them:

You can see from the above table that New Zealand’s average sunshine levels are higher than Germany’s and comparable to Japan, and yet, both Germany and Japan have much higher solar energy generation.

One may argue that these countries also have much higher populations, but a look at the per capita solar installed capacity shows that even after accounting for the population difference, both the above-mentioned countries generate four to eight times the solar energy per person than we do, despite similar or lower sunshine levels.

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System Size Recommendations For Different New Zealand Regions

Imagine an exactly identical, hypothetical home that’s located in every single New Zealand region. Suppose the home uses the same energy everywhere; would it have the same system size? Obviously not. Regions with high sunshine potential will need smaller systems, as they will generate more power. On the contrary, regions with lower sunlight will need larger systems.

Assuming the average household energy consumption of around 7,000 kWh per year, northern regions with over 1,400 peak sunshine hours will find a 6–7 kW system sufficient, while Southern regions will need 8–10 kW of solar panels to fulfil their energy needs. Mid-range regions, on the other hand, will need a 7–8 kW system. Note that the above analysis considers a uniform 7,000 kWh annual consumption, but this will vary with numerous factors.

Ultimately, your solar installer will always design the system and size it based on things such as your energy consumption levels, location, roof size, orientation, and budget.

Theoretical Vs. Actual Solar Generation

Think about a car’s official fuel-efficiency rating. It’s measured under standardised test conditions so you can fairly compare one model with another, but your actual fuel use will vary depending on how and where you drive.

Solar panels work in much the same way.

A solar panel rated at 400 watts has what’s known as a 400 Wp rating, with the “p” standing for “peak”. This rating is measured under Standard Test Conditions (STC) – a consistent set of laboratory conditions used by manufacturers around the world to test and compare panel performance.

In the real world, conditions are constantly changing. Sunlight intensity, panel temperature, roof angle, shading and even the time of day all affect how much power a panel produces at any given moment. So a 400 Wp panel won’t simply produce 400 watts all day.

There are also normal system losses to account for, including inverter losses, higher panel temperatures, dust or bird droppings, cable losses and gradual panel degradation over time.

Because of this, the actual output of a solar power system will usually be lower than its theoretical peak rating. At any particular moment, output might be close to the system’s rated capacity under excellent conditions, or considerably lower when conditions are less favourable.

This is also where good equipment and good system design matter. Quality panels generally perform better in high temperatures and degrade more slowly over time, while an experienced solar installer will make sure the system is properly sized and designed around your roof, orientation, shading and local conditions.