FAQs

How does solar energy work?

SUNZ can help you harness the sun’s energy and access free solar power – 365 days a year! There are three main types of solar energy panels, generating heat, electricity, or a combination of both

1. PV (Photo Voltaic) solar panels: The solar power cells covert sunlight directly into electricity.
2. Thermal solar panels: Water is heated as it runs through the cells and is then used directly as hot water, or to heat the home.
3. PVT (Photo Voltaic Thermal) hybrid solar panels: The latest technology combines the benefits of both solar power and heat generation.

What happens at night or when it’s cloudy?

SUNZ solar power systems still work when it is cloudy, there is just less energy available. The solar controllers automatically determine whether or not it is viable to run the solar power system via the use of two or more sensors (one on the roof in the solar panel, and one at the bottom of the hot water cylinder). If the temperature in the panel is significantly hotter than the bottom of the cylinder, then the solar is turned on. As the hot water cylinder heats up and approaches the temperature in the panel, the system will shut down.

Why should I invest in a solar power system?

Heating of hot water consumes vast amounts of electricity that can be saved by installing a solar hot water system. A solar hot water heating system using the sun’s energy can pay for itself many times over the life of the system through lower power bills. Hot water represents up to 48% of your power account (New Zealand Government EECA Report). A solar hot water system normally sized will heat up to 90% of your hot water during summer months, and 40% during winter months. This represents about 33% of your power bill. Installing a solar system will also increase the value of your home. Find out more about Why SUNZ offers the best solar energy systems available.

Are solar panels prone to frost damage?

One of the most common reasons for leaks in solar panels is because the material used in many systems is neither flexible nor strong enough to withstand the expansion and contraction that occurs during seasonal temperature changes.
This is especially true in cases of internal freeze. Because water expands by approximately 9% when turning to ice, the strain put on solar panels flow channel can be devastating hence frost protection becomes an essential component of any solar heating system. There are several different ways a solar power system can be installed due to the different applications and locations to prevent frost damage. We predominantly used the frost function on the Controllers, or drain down systems to protect against frosts. Other ways include using a food grade antifreeze and heat exchanges or frost plugs.

What size system will I need?

This depends on the number of people in your household and the size of your hot water cylinder. Our aim is to ensure that your solar system meets the needs of your family.
Here are some rough guidelines:
1-2 adults with a 135-150 litre hot water cylinder require a 1 standard size (2.00 sqm) panel system.
2-3 adults with a 180-200 litre hot water cylinder require a 1 large size (2.5 sqm) panel system.
3-4 adults with a 220-300 litre hot water cylinder require a 2 standard size panel system.
5-6 adults with a 300-500 litre hot water cylinder require a 2 large size panel system.

Can extra panels be added later if our family grows (or if we decide to heat our pool?)

Yes. The panels are modular and designed for easy add-ons.

Can the system be installed to existing hot water cylinders?

Yes, the answer is almost always yes. Installing solar to your existing hot water cylinder may not be efficient however. Refer to sizing above. If your cylinder is not big enough, then the solar will not be efficient.

Does installing Solar have an affect the water pressure?

No, solar and be installed on both Mains and low pressure cylinders. The solar heating system does not affect the water pressure.

Where will the panels be put?

Preferably on a north-facing roof as close as possible to the hot water cylinder. Second choice is facing the afternoon sun (north-west). Third choice is facing the morning sun (north-east). Never facing south. The panels can tolerate a large variation off north with little loss in efficiency.

What is so great about your SUNZ solar power systems?

Us! Your local SUNZ solar energy specialists are fully trained and experienced installers. You can have the best equipment, but if the installer recommends the wrong system, or installs a component incorrectly, you have a disaster waiting to happen. Our nationwide network of SUNZ Solar Energy Specialists, backed up by our head office technical support, ensure our customers get high performing solar energy solutions built to last. Find out more about Why SUNZ offers the best solar energy systems available.

What length of warranty do you offer on your system?

10 years on the panels and manufacturer’s warranty on other components. SUNZ Techno-solis solar pool heating products have a lifetime warranty.

What is the estimated life of your system?

Open circuit systems have a life expectancy of 25 years. Close circuit and drainback systems have a life expectancy of 40 years.

What are the maintenance requirements?

Occasional cleaning of the glass cover helps maintain efficiency. In the long term we recommend replacing a valve at 6 years, and at 12 years replace the seals.

What are the points of difference from other solar heating systems?

Pure copper collector for long life. We only work with the best products and latest technology available. No ugly and heavy tank on the roof. We specialise in pumped systems which have been proved to be most efficient. All our installations are undertaken by our nationwide network of SUNZ Solar Energy Specialists. Our hand-picked team are all fully qualified plumbers and specifically trained in SUNZ solar energy systems.

Why do you not have a tank on the roof?

Pumped, or active systems have proved more efficient that thermosyphon (tank on roof). Horizontal tanks are very inefficient. They lose lots of heat, and you can only get 1/3 of the hot water out of a horizontal tank when compared to the same size vertical tank.

How heavy are the solar collectors?

Our standard collectors weigh around 20kg/meter.

What is the most important factor in getting an efficient solar heating system?

Storage. Storage is by far the most important factor. Very rarely are people home during showering during the day when the sun is out, so the solar energy must be stored until at night or the next morning for use. If your storage cylinder is inadequate, you will not have a good system. If you can afford (space and money) to installer a bigger than required cylinder, then the system will be more efficient, because one day’s solar energy can be stored and used over the next few bad weather days without requiring backup energy.

I heard Evacuated Tubes are more efficient than Flat plates, Is this true?

In certain applications Evacuated tubes are more efficient that Flat Plates, but in other applications, Flat Plates are more efficient that Evacuated Tubes. Unglazed pool heating collectors are actually more efficient than both Flat plates and evacuated tubes in certain applications. The advantage the Evacuated Tube has over flat plates is that they lose less heat, (function of the vacuum). This has advantages in applications that require very hot water, and is why the stagnation temperatures of most evacuated tubes is very high. This is why evacuated tubes are used commercially to generate steam. For a residential hot water system, the target temperature is 60 degrees C, and anything over 85 degrees C is undesirable and can cause problems. Heating water to 60 degrees C is New Zealand’s climate, there is very little performance difference in the two technologies.