There is a growing increase in the installation of residential solar power systems.


Today there are two main types of solar power systems. The first is a solar power system that generates power and the other is a solar hot water system that generates hot water. In this article the Style Plus team looks at solar power system options:

• How Does A Solar Power System Work?
• Solar Power System Quality?
• Off-Grid Connection & Solar Power Battery Storage
• Grid-Tied
• Cost & Size of a Solar Power System

How Does A Solar Power System Work?


Solar power systems basically use solar photovoltaic panels/modules that turn energy from sunlight into electricity.

Viewing standard solar panels you will see at least a dozen silicon squares within the frame – solar cells. These solar cells convert sunlight (photons) into an electrical current. As DC electricity is created from the solar cells, the inverter converts the current into AC electricity so that it can be used by the home.

Solar power systems usually include:

• Solar panels, cables, and mounting hardware.

• An inverter and controller – the inverter unit converts DC electricity from the solar panels into AC electricity (mains).

• Smart meter to record the electricity generated / exported to the grid.

• For off-grid situations, batteries, back-up generators, and other specialist components.


The quality of solar panels available in the market today varies. For example, the type of aluminium used for the solar panel frame, the thickness and quality of the solder, the efficiency and quality of the solar cell, the water seal over time, the way the cells are encapsulated, the protection against micro cracking, the UV resistance of the backing sheet, the quality of the cables and plugs. Combining these factors determine the quality and longevity of the solar panel.

Off-Grid Connection & Solar Power Battery Storage


For most solar power users, the motivation to install batteries is due to the low buyback rates they get for exporting solar power to the grid. It makes sense to use as much of your solar power as possible rather than exporting solar power.


With modern solar power systems and evolving battery storage systems, there is now an opportunity to be fully self-sufficient – going “off-grid”.

When looking at costs for an average New Zealand home to be powered by a solar powered system and off-grid, the starting price for a system would be around $38,000. Off-grid systems are more expensive due to the system that controls the batteries, along with the batteries themselves. However, battery technology is constantly improving and reducing in cost.


Storing power in batteries which can be used at any time of the day is a way to increase solar power self-consumption. Battery systems are still relatively expensive. If you choose to purchase a grid connected system and batteries are still out of your budget, then you can always add batteries to your system in the future.


The general goal when designing an off-grid battery bank is to get a system that is big enough to supply all your needs for a few cloudy days, but is also small enough to be charged by your panels. However there are a few things to consider:

• Would you prefer enough storage to make it all the way through the night without needing to buy grid power too often?

• Is blackout protection functionality important to you?

• Do you require a system that will enable you to go off-grid in the future?

• How much energy you consume at night, especially during the winter months will indicate how much storage you will require.

• If you have solar power system currently installed, then how much you have been exporting to the grid during the winter months is a good indicator on how much battery capacity to purchase.



There is an alternative power system designed for homes where the home is connected to the mains grid electricity provider. These systems are called ‘grid-connected’, ‘grid-tied’, or ‘grid-interactive’.

These systems enable you to produce your own power which reduces your electricity bill and any excess power that is made can be fed back into the mains grid electricity provider.

For example, when the system is generating more electricity than is needed, for example, during the day when no one is home, you could be paid for the surplus.

Each electricity retailer has their specific terms and conditions for buying excess electricity. The price that they offer per kilowatt hour (kWh), called the ‘buy-back’ price, will also vary.

• Meridian Energy – Go Solar.
• Genesis Energy – HomeGen.
• P2 Power – SolarShare.

Solar Power Costs


To give you an idea about the range of sizes available for solar power systems, the smallest system a solar power installation company will generally offer is a 1.5kW system. Home solar power systems rarely do not get systems over the 8kW size.

Solar power costs varies depending mainly on the system size you select and the type of roof you have.

A 3kW solar power system size is a popular system size in New Zealand. This is due to the fact that it will make a significant change to your power bill. The cost is from $10,000.

Tip: For your renovation or new build, spending a little time researching whether a company is really giving you value for your money will be well worth your time.

Book your consultation today and kick start your renovation project!

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