Solar Electric Systems

About Solar Electric Systems 

Solar electric systems steadily grow in numbers as a power-supply method of choice in New Zealand, year by year. Photovoltaic modules, also known as solar electric modules, belong to the most energy-efficient systems available, using a free and sustainable source - sunlight - to convert it to electricity. 

Solar generator collects direct current (DC) electricity and sends it to the solar inverter for transforming into AC (alternating) power, prevalently used in households. The solar panel then distributes the accumulated electricity to the spenders, such as home appliances. A battery can be incorporated into this system to preserve the unspent power and act as a support during the night or a blackout.

Solar electric systems can be connected to the existing power grid in New Zealand, allowing owners to use it as a backup source of power or sell excessive electricity back to the utility for compensation. 

Types of Solar Electric Systems in New Zealand

Solar Inverters

A solar inverter is a device that transfers the DC power accumulated in the solar panels into functional, AC power.

Most units are waterproof and designed for outdoor use, and the best place to install a solar inverter is close to the main switchboard. However, added protection can extend the appliance's life span. In New Zealand it's strongly recommended to place it on a shaded part of the wall or under a specially designed awning/inside a protective box. 

• String inverter: This is the simplest and most affordable model. It works on a sequence connection basis, where each panel affects all the rest. 
• Microinverters: Designed in a compact form, allowing each panel to be connected to its own unit for more independent operation. Microinverters are ideal for use in areas with shading periods and as a part of expandable networks. 
• Hybrid inverters: Hybrid systems allow adding a separately purchased storage battery. However, depending on the manufacturers, some limitations of compatibility can be faced during battery selection.  
• Battery inverters: Designed for use specifically with the systems equipped with a storage battery.

Solar Panels

Solar panels are composed of two layers of semi-conducting material sandwiched between a network of photovoltaic cells. They work by establishing an electric field by charging the opposite layers. When the field is formed, the panels start collecting solar energy. 

Three standard types of PV panels in New Zealand include monocrystalline, polycrystalline/multi crystalline, and thin-film designs. 

• Monocrystalline: A highly efficient, silicone-based model with superior performance, recognised by strong black hue.
• Polycrystalline: A standard solution, more affordable than monocrystalline units. It's made from silicone fragments melted together, identified by a characteristic blue glare.
• Thin-film: Portable solar panels made from a range of materials, created for flexibility of use. Their practical, low-profile design is suited for different applications, including tiny houses and camper vans. 

Modern solar panels in New Zealand also come in a hybrid form as a combination of thermal and photovoltaic technologies, while the bifacial design maximises conventional solar electric systems' generating/production capacity. 

Solar Panel Substructure

Photovoltaic substructure includes various types of mounting systems, designed to securely attach solar panels to a variety of surfaces. Module racking allows roof fitting, connecting panels to building facades and balconies, or mounting them to the ground.

Most PV module mounting systems in New Zealand allow the installation of solar panels as functional parts of a building structure.

Fixed systems comprise a range of galvanised steel structures, designed for fast and secure angled mounting of PV panels. Sun-tracking systems, on the other hand, are more versatile and available in single or double form. The third type of mounting system is designed for connecting to the grid.

Solar Roof Tiles

Solar roof tiles mimic the appearance of regular roofing tiles while performing as highly functional power collectors. Also called photovoltaic shingles, these thin sheets can be installed on almost any roof, either by replacing the existing tiles or fixed on top of them. 

Solar PV tiles in New Zealand are mostly made from copper indium gallium selenide, which allows them to be shaped in the form of super-thin films. This semiconductor material features one of the highest conversion efficiency rates; however, more conventional monocrystalline silicon is also used in PV shingles production.  

Solar Storage Batteries

Battery storage is a convenient way to maximise the utility of off-grid solar electric systems by preserving the excessive energy collected during the day. In systems with a grid connection in New Zealand, a battery allows the user to make the accumulated power even more cost-efficient by sending it to the system. 

• Lithium-ion: Durable and suitable for a range of ambient temperatures with a discharge of up to 90% overall capacity.
• NMC: Offers the best ratio between the storage and the required space, also offering the highest safety ratings.
• Lead-Acid/Lead-Carbon: A reliable, eco-friendly, large-scale energy storage solution.
• Flow Battery: Based on pumped electrolytes, with discharging capability of up to 100% without residue.

Solar Electric Systems Maintenance 

Solar electric systems do not require excessive maintenance in New Zealand. Dust, debris, or leaves accumulated on the panel surfaces can be brushed or hosed down easily. Other than that, only occasional inspections are required to make sure that the system is completely functional. In case of any particular requirements, the instructions should be featured in the manufacturers manual. 

Solar panels warranty typically applies to 25 years in New Zealand, while the inverter carries a 5 to 10 years life span guarantee. Most inverters need to be replaced after 15 years maximum.  

If there are no notable issues, a professional should examine the entire system once every five years. 

Things to Consider Before Buying Solar Electric Systems

Solar panels are most efficient when placed angled on an angled roof facing the sun path, or mounted to the ground far from any shading source.  

On average, east-facing panels generate the most power in the morning, while the west-facing units maximise their utility during the late afternoon. North-facing solar panels have the steadiest gathering properties but lower overall performance than east- and west-oriented units. Sun-tracking systems have the highest accumulation power. 

The solar panels are most effective at 30-35 degrees. However, the angle may change depending on the location.  

If you need assistance to find the right solar electric systems for your home or office, ArchiPro provides a connection to various professionals in New Zealand, ready to assist with all requirements and questions. Simply click "Contact supplier" on the product's page, or visit the supplier's website directly from the product's page.