Frequently Asked Questions

Advantages of Solar Power

Solar energy is a resource that is not only sustainable for energy consumption, it is indefinitely renewable. Advantages of Solar Power include:

• Solar panels require little maintenance and do not require any type of mechanical parts that can fail.
• Solar panels are also a silent producer of energy, and extremely easy to install.
• The amount of solar energy that hits the Earth in a single day could power the world for 2 years!

A current-voltage (I-V) curve shows the possible combinations of current and voltage output of a solar cell. A solar cell, produces its maximum current when there is no resistance in the circuit, i.e., when there is a short circuit between its positive and negative terminals. Each Suntech Solar Panel is assigned a barcode, tested in the Lab, and results are made available to customers.

Electroluminscence image of a monocrystalline silicon wafer. The intensity of the light given off is proportional to the voltage, so poorly contacted and inactive regions show up as dark areas. The micocrack and printing problem are not detectable with visual inspection. Each Suntech Solar Panel is assigned a barcode, tested in the Lab, and results are made available to customers.

Ethylene tetrafluoroethylene (ETFE) is a fluorine-based plastic. It was designed to have high corrosion resistance and strength over a wide temperature range. ETFE is a polymerand its source-based name is poly(ethene-co-tetrafluoroethene). ETFE has a relatively high melting temperature, excellent chemical, electrical and high-energy radiation resistance properties.

ETFE Solar Panels – using the ETFE solar panel technology provide ultra-thin UV resistant, waterproof panels. The key benefits of ETFE (Ethylene Tetrafluoroethylene) coated solar panels is that they are ultra lightweight, durable and are ideal for boats, cars, RV’s, buses, and much more. The ETFE coated panels provide a non-stick, easy to clean surface. Dirt, dust and pollens are less likely to contaminate the surface of the panels; water or a damp cloth (or some rain) will typically remove these particles which would otherwise block sunlight from reaching the solar panels.
ETFE, unlike glass or urethane is a lighter, thinner protective coating with high UV resistance and reliability during extended outdoor usage.

The panels are 1150mm long by 555mm wide. Only 3.2mm thick!!

They weight 1.8 kg, 4 lbs each.

Solar cell efficiency equals 90% up to ten years and 80% up to 20 years.

Solar panels achieve maximum output in direct sunlight, but they work in normal daylight and cloudy weather too. The amount of power a 12v solar panel or charging kit generates in cloudy weather will be lower compared to direct sunlight. If your solar panel is being used to charge batteries, the charging time will be longer in cloudy weather. Using a MPPT solar charge controller will improve your solar panels performance in cloudy weather by refreshing itself when the sun comes out again.

This will depend on how it is used, whether it is recharged regularly and not discharged excessively. The general principle is that the less the battery is discharged before recharging, the greater number of charge-discharge cycles it will have in its lifetime. For example, a battery which is regularly discharged by 80% (only 20% charge remaining) will have a much shorter lifespan compared to a battery which is discharged by only 30% (with 70% charge remaining). Completely draining a battery might permanently reduce the total capacity. Some batteries (such as deep cycle) can better tolerate this, but it’s still not healthy for them. Our advice is not to discharge your battery excessively and to recharge it as soon as possible.

MPPT or Maximum Power Point Tracking is an algorithm in charge controllers used for extracting maximum available power from Solar Panels under certain conditions. The maximum voltage which the panel can produce is called ‘maximum power point’ (or peak power voltage). Maximum power varies with solar rays, ambient temperature and solar cell temperature.

Pulse Width Modulation. The PWM controller is in essence a switch that connects a solar array to a battery. The result is that the voltage of the array will be pulled down to near that of the battery.

The PWM controller is far less expensive to buy, and the reason why most solar kits found in stores seem affordable.

Suntech Solar uses the MPPT controller which is a far more sophisticated controller, : it will adjust its input voltage to harvest the maximum power from the solar array and then transform this power to supply the varying voltage requirement, of the battery plus load. Thus, it essentially decouples the array and battery voltages so that there can be, for example, a 12 volt battery on one side of the MPPT charge controller and a large number of cells wired in series to produce 36 volts on the other.

The PWM controller is in essence a switch that connects a solar array to a battery. The result is that the voltage of the array will be pulled down to near that of the battery.

The MPPT controller is more sophisticated (and more expensive): it will adjust its input voltage to harvest the maximum power from the solar array and then transform this power to supply the varying voltage requirement, of the battery plus load. Thus, it essentially decouples the array and battery voltages so that there can be, for example, a 12 volt battery on one side of the MPPT charge controller and a large number of cells wired in series to produce 36 volts on the other.

The MPPT controller are most effective under these circumstances:

Cool, and/or cloudy or hazy days – when the extra power is needed the most.

• Cold weather – solar panels work better at cold temperatures, but without a MPPT you are losing most of that. Cold weather is most likely in spring/fall seasons – the time when sun hours are low and you need the power to recharge batteries the most.
• Low battery charge – the lower the state of charge in your battery, the more current a MPPT puts into them – another time when the extra power is needed the most. You can have both of these conditions at the same time.
• Long wire runs – If you are charging a 12 volt battery, and your panels are 50 feet away, the voltage drop and power loss can be considerable unless you use very large wire. That can be very expensive. But if you have four 12 volt panels wired in series for 48 volts, the power loss is much less, and the controller will convert that high voltage to 12 volts at the battery. That also means that if you have a high voltage panel setup feeding the controller, you can use much smaller wire.

Suntech Solar only uses MPPT controllers. Although the cost is higher, they are far more efficient for a 12/24 volt application. With a PWM controller you are not utilizing all the power that the solar panels are producing. You are limiting your power intake by the current voltage of your battery.

For Example:
If you have a 3 panel system wired in series, you have a potential for 60.18 Volts at 6 amps coming into your MPPT controller. Your controller will convert this to a useable 12 volts, and 18 amps going to your loads, or charging your batteries!

With a PWM controller the voltage of the array (60.18v.) will be pulled down to that of the battery. (12 Volts) Therefor the MPPT controller is far more efficient than the PWM.

SUNPOWER panels are covered for 2 years manufacturer defects and 5 years performance warranty.

Do not wire a device directly to the solar panel, the voltage is too high and will result in damage to your device. Smaller DC loads can be wired into the solar controller, however it is highly recommended to wire the panels through a controller to a battery, or battery bank. The size of your battery bank will also match the size of load you are running. For AC current, wire an invertor to the battery bank and plug your load into the invertor. Our kits do come with complete instructions, and we can also be contacted at support@suntechsolar.ca for assistance.

The differences between these two types of solar panels relate to the manufacturing process used rather than product characteristics. Monocrystalline solar cells are produced from a single crystal of silicon while polycrystalline solar cells are produced from a piece of silicon consisting of many crystals.

Monocrystalline cells therefore have a continuous and unbroken structure, with an even external colour. In contrast, polycrystalline silicon has visible grain boundaries and a “metal flake” look.

Solar panel properties for these two types of cells are very similar, however polycrystalline solar panels require slightly more space than monocrystalline with the same power rating.

Depending on the system size. Your solar charge controller and local electrical codes will dictate your max VDC. The advantage of series connection would be allowing for smaller conductor size and protection from shading.

When wiring in series, we add the voltage from panel to panel but the amperage stays the same.

This allows us to use the 10 Gauge wire that comes supplied in your solar kit.

The high voltage is then brought down to battery voltage in the controller, and the amps are magnified to charge the batteries. Note, a properly sized circuit breaker is recommended at the battery connection.

Please see our portable solar panel wiring diagram in the Resources Section of this website.