General FAQs
Solar panels are expected to last for at least 25 years, as all good solar manufacturers give their solar panels a 25 - 30 year performance warranty. But since solar panels have no moving parts, they are expected to last much longer than 25 years. Solar panels will degrade over time, at the 25-year mark they shouldn’t have degraded by more than 80%. This means the solar panels should be producing at least 80% of the amount of what they produced on day one.
A grid-connected solar power system is the simplest type of system where solar panels are installed on a roof and will produce power. Solar will power any electrical appliance, like a television and heat pump. Excess solar power that the home or business doesn’t need will be sent to the grid, in exchange for credit from your selected electricity retailer. Read more about grid-connected solar power systems here.
Solar energy is the light and heat energy that radiates from the sun. The sun's energy can be captured in the form of light from solar photovoltaic panels and can be captured in the form of heat by solar hot water collectors.
Solar panels are also known as solar photovoltaic panels or solar PV panels. Photovoltaics (PV) is the process of generating electricity by converting solar radiation into direct current (DC) electricity using semiconductors.
Yes solar panels are a worthwhile investment in New Zealand. They can save a home hundreds to thousands of dollars off power bills each year. While the return on investment (ROI) can vary, you should expect an ROI of 10% or higher from a residential solar installer. The ROI is much higher on a commercial solar panel installation. Solar panels are a 100% renewable energy resource, therefore great for the planet.
Putting panels on a north-facing roof is optimal for generating the maximum amount of solar power over the course of a day. Placing panels on an east or west-facing roof will still produce a substantial amount of power, but not quite as much as panels on a north-facing roof. Panels will not perform well if they face south and is never recommended in New Zealand.
The amount of electricity each solar panel generates depends on the angle and orientation of the panel-the optimum position faces directly north and is angled approximately 25-30° from flat. Different areas of New Zealand get different amounts of sunlight, which affects the performance of solar panels. If there is any shade on the panels, the output will be reduced.
Typically the payback period would be between 8 and 10 years to make up for the initial investment of the solar power system. This depends on how much electricity the system generates and what the value of this electricity is. For example if you spend $10,000 on a system and it produces $1,000 worth of of power each year then the payback period would be 10 years. But as the price of electricity is increasing every year, you can expect the value of your electricity to increase, therefore the payback period would be faster than 10 years. Click here to work out the payback period of a solar power system using our calculator.
Currently, the best way to finance a solar power system is through a home loan. Most banks now recognise a solar power system as an asset for your home and are happy to add a solar power system to your mortgage. Getting finance for a solar power system still makes the investment worth it, for example, if your mortgage rate is 3% and your return on investment for the system is 10% you are still earning 7%.
You are pretty much free to pick any system size you like and are only restricted by the space you have on your roof, your budget and restraints (if any) imposed by the retail or lines companies.
The average-sized solar power system being installed in New Zealand is currently a 4kW solar power system.
Many people go for system sizes that heavily reduces their electricity bills. Check out our solar calculator to see how much different system sizes will reduce your power bill by.
If your home or building is built to code, you will be able to install a solar power system on it. Roofs that are up to code can withstand the weight of the solar panels.
Solar power is an electrical unit that provides electricity to electrical appliances in the house. A solar hot-water system is a form of plumbing that creates hot water for all of your hot-water needs.
Monocrystalline panels are made of solar photovoltaic cells cut from a solid silicon crystal. This type of panel will normally produce the most power per unit of surface area. They are great for people who have limited space on their roofs.
Polycrystalline panels, also known as multicrystalline panels, have solar cells made of a number of small silicon crystals. Typically, these types of panels produce less power per unit than monocrystalline panels, but, because of advancements in technology, polycrystalline panels have caught up in power production and are now close behind monocrystalline panels. Given that polycrystalline panels are normally cheaper than monocrystalline panels, they can sometimes be the better choice.
Thin-film solar panels have cells made up by a thin layer of photovoltaic material deposited on a substrate. Thin-film panels are not as robust as the above two types of solar panels and are not expected to last as long.
Learn more here about the different types of solar panels.
You can expect the solar panels to last more than twenty-five years, as all solar panels have at least a 25-year performance warranty, some now offer a 30-year performance warranty. The inverter may need replacing in about twelve to fifteen years.
Different components of the system will come with different warranty lengths. Normally solar panels have a 25-30 year performance warranty, with a 10-25 product warranty. Inverters normally have a 5-12 year warranty. The workmanship on the solar installation is normally around 10 years.
Below are solar panel brands available in New Zealand.
- Canadian Solar
- Hyundai
- JA Solar
- Jinko
- LG
- Q.Peak
- rec
- Trina Solar
- Winaico
- Yingli
See how efficient all of these solar panels are here.
Common Solar Inverter Brand Names in New Zealand
- SMA Solar
- Fronius
- Solaredge
- Enphase
- ABB
- Delta
- SolaX
- Growatt
- GoodWe
- Sungrow
Most insurance companies will insure solar power systems. Be sure to call your insurance provider before purchasing the system.
There is very little maintenance involved with a solar panel system. You may want to give your panels a quick wash once a year with some soapy water and a soft brush. Most solar power systems come with online monitoring software. I would recommend solar power owners to check the monitor at least once a month, if there is a significant drop in power production that can't be explained by the recent weather, it is then recommended you call the company that installed the solar power system and ask them to look into it. View our full solar maintenance guide here.
Yes. You can ask for a system that will allow for scaling-up in the future. This usually requires that you purchase an inverter larger than that of your current system size. For example, by purchasing a 3-kW system with a 5-kW inverter, you can scale up to a 5-kW system in the future. There are some limitations to doing this, so make sure you ask your sales representative about this option before you go ahead with a system.
The grid-connected solar power system will automatically shut down for safety reasons. If you need power during blackouts, ask your sales representative about the possibility of adding solar batteries, such as a Tesla Powerwall or sonnenBattery to the system, which will still allow the solar power system to operate during a black-out.
A solar power system can still produce some power on cloudy, overcast days, just not as much. If there is a lot of cloud cover and the system is producing hardly any power, then the system may turn off.
Installation FAQs
We do not recommend installing a solar power system yourself, it can be dangerous, if not installed properly then the solar panels and components will be voided, and will most likely cost you more money in the long run. Read more about the dangers of DIY solar here.
The system is connected to your electrical switchboard and power is then distributed according to the power requirements of the house.
Usually, the solar inverter is placed alongside the fuse box or in the garage. The inverter is silent and has a display to show the electricity generated. Some solar inverters can be mounted on an exterior wall.
The most commonly installed solar panel size on a residential system is between 300W to 400W panel. The average dimensions of a solar panel is 1700 x 998 x 35 mm. There is no standard-sized solar panel, they all vary between brands and models.
Yes, approval from the lines company is always required before installing a grid-connected solar power system. Lines companies require a form to be filled out, which is usually taken care of by your choosen solar installer. Most lines companies require an administration fee between $90 and $200, a few don’t charge anything. An inspection fee may be charged if an inspection is required. Find the list of all lines companies solar connection fees here.
One solar panel weighs approximately 10 - 12 kgs per square metre (depending on the brand). A 300W panel weighs around 18kgs. A standard residential 3 kW system needs approximately 10 solar panels and will weigh around 180kg in solar panels alone.
