Empower yourself. Learn about how Solar Panels work in a Solar Energy Power System
On this page:
What is an MPPT and How Does It Work?
How many Solar Panels can one connect to an Inverter?
How much power do typical household appliances consume?
Advantages of ground-based aluminium Solar Panel Mounting Structures
Protective fencing for ground-based aluminium Solar Panel Mounting Structures
An example of a Solar Panel Array Configuration using (for example) 36 x 560 Watt Solar Panels
What is the ‘Cloud Enhancement Effect’ on Panel Voltage?
About Current ratings for Circuit Breakers and Fuses
About Solar Panels
Watch a Youtube Video: How do Solar Panels work?
Solar Panels (Photovoltaic panels) convert Sunlight into DC (Direct Current) electrical Power.
The Solar Panel is made up of many smaller units called solar cells, which are made of silicon, a common material found in sand.
When sunlight hits these cells, it knocks electrons loose, creating an electric current.
The DC electrical power produced by the Solar Panel is measured in Watts.
A Solar Panel is rated to produce a certain maximum amount of Watts of electrical power under optimum Sunny conditions (also known as the maximum peak power rating of the Panel).
Depending on the size and the design of the Solar Panel, there are many different maximum outputs available, for example 50 Watts, 100 Watts, 200 Watts, 450 Watts, 545 Watts, 555 Watts, 560 Watts
Bright Future Solar sells and distributes Solar Panels procured from Herholdt’s Solar Equipment wholesalers in the range of 550 Watts to 560 Watts… depending on which panels are in stock at any one time and at the best price.
Under less than optimum Sunny conditions the solar panels will continue to produce electrical power… so long as there is daylight even if there is 100% cloud cover.
The panels do not need direct sunlight in order to function.
Under cloudy conditions, even with 100% cloud cover, the panels may still produce up to +- 60% of their peak power rating depending on the ‘thickness’ of the clouds especially between 10am to 3pm.
Under dark clouds and rain, the panels will still (usually) produce at least +- 10% of their peak power output rating and even up to 30% between 10am and 3pm.
In Winter months, even if the temperature is very cold (e.g. zero), the panels may still produce 80% to 100% of their peak power output between 10am to 3pm so long as there are no clouds.
What is an MPPT and How Does It Work?
To supply power to the Sunsynk Inverter, one installs a Solar Panel Array consisting of at least 4 panels in series… and preferably more.
Much larger Solar Panels Arrays (for example 36 Panels) will have configurations that are a mix of series and parallel connections.
Why at least four?
Sunsynk Inverters (and other Brands) have Solar Panel Array DC power input management components called MPPT’s.
The MPPT’s function is to manage and maximise the DC Power input being supplied by the Solar Panel Array and then to distribute that power to the Inverter which in turn converts that DC power into AC power for your premises and then uses any excess power (after supplying the premises) to charge your batteries.
MPPT stands for Maximum Power Point Tracking. It’s a technology used in solar inverters to ensure that your solar panels operate at their optimal power output.
Solar panels have a characteristic called the power curve, where they produce the maximum amount of power at a particular combination of voltage and current.
This combination is known as the Maximum Power Point (MPP). However, the MPP can change due to factors like temperature, shading, and the angle of sunlight.
An MPPT system constantly monitors the voltage and current output of the solar panels and adjusts the load to ensure the panels are operating at their MPP.
By doing so, it maximizes the energy harvest from the solar panels, improving the overall efficiency of the solar power system.
In this way, the Solar Panel Array feeds DC Power through the MPPT’s and into the Inverter which in turn converts the DC Power into AC Power to provide electricity to your premises.
The Inverter uses the excess Solar Panel Array DC Power to charge the Batteries.
The excess power is the amount of power in Watts that is more or less the difference between the total Solar Panel Array Input Power and the power consumption (in Watts) of the premises at any one time.
The more Solar Panels the Solar Panel Array has, the more DC Power can be produced.
Key Functions of MPPT:
- Voltage Optimization: Adjusts the panel voltage to achieve maximum power output.
- Improved Efficiency: Increases the efficiency of the solar power system by up to 30%.
- Adaptability: Responds dynamically to changes in sunlight conditions and other environmental factors.
Example:
Imagine you’re driving a car and trying to maintain the best fuel efficiency by adjusting your speed according to the terrain. MPPT does something similar for solar panels, ensuring they extract the most power possible regardless of changing conditions.
An Inverter has several MPPT’s to manage the DC Power input. The higher the output capacity of the Inverter the more MPPT’s it will have.
In the case of the SunSynk 16 kW Inverter there are 3 MPPT’s and two strings of Solar Panels can be added to each MPPT.
A ‘string’ of panels usually consists of 4 to 8 panels.
A Solar Panel (depending on the brand and the peak output capacity) can, for example, have a Voltage rating of around 49 Volts.
Each MPPT has a Voltage operating range of usually 150 Volts minimum to 425 Volts maximum.
Solar Panels must be combined in Series in order to at least meet the minimum Voltage requirements of the MPPT to which the string (or strings) is connected.
When Solar Panels are combined in Series then the Voltages of each panel are combined together.
For Example:
3 Panels of 49 Volts each will produce 147 Volts
Thus 3 x 49 Volt panels is not enough to meet the minimum requirements of the MPPT in the 16 kW Sunsynk Inverter.
Four panels in series however will produce around 196 Volts which is comfortably over the minimum requirement.
It is of utmost importance that the Voltage Range of the MPPT is adhered to when planning how many Solar Panels can be connected to an MPPT.
Too Low — Inverter will not operate
Too High – Inverter will be damaged
It is equally important that the total current (Amps) supplied by the Solar Panel Array does not exceed the Inverters maximum current input rating per MPPT
The 16 kW Sunsynk Inverter can utilize 26 Amps per MPPT but can receive a maximum of 44 Amps per MPPT.
Different output capacity Inverters have different maximum DC input power ratings.
How does connecting Solar Panels in Series and/or Parallel affect the output Voltage and the Current?
For example, a Solar Panel that has a maximum output Wattage of 560 Watts with a Current rating of 13.96 Amps and a Voltage rating of 49.4 Volts:
Panels connected in series:
The Voltage of each added panel in series is added to the total Voltage.
For example 2 panels of 49.4 Volts each connected in series will produce 2 x 49.4 Volts = 98.8 Volts max.
The Current stays the same (13.96 Amps in our example) regardless of the number of panels in series.
The peak Watts output of each panel is added to the total peak Wattage. Thus 2 x 560 Watt panels in series will produce 2 x 560 Watts = 1120 Watts max.
Panels connected in Parallel:
The Voltage stays the same, for example two panels each with a Voltage of 49.4 Volts connected in parallel will still produce 49.4 Volts.
However, the Current (Amps) of each added panel in parallel is added to the total Current.
The Watts output of each panel is added to the total Wattage.
Thus the same two panels connected in parallel (instead of in series) will produce a maximum of 49.4 Volts, maximum 1120 Watts (2 x 560 Watts) and the current will double to 27.92 Amps.
Or for example: 2 strings of Panels where each string has 6 x 560 Watt Panels in Series and the strings are connected together in Parallel:
The total maximum Voltage for each string will be 6 x 49.4 = 296.4 Volts.
The total maximum Wattage for each string is 6 x 560 Watts = 3360 Watts.
The Current for each string stays at 13.96 Amps.
When the two strings are connected together in Parallel:
The Voltage stays the same at 296.4 Volts.
The Current doubles to 27.92 Amps.
The total maximum Wattage becomes 3360 Watts x 2 = 6720 Watts (which is 560 Watts x 12 Panels)
How many Solar Panels can one connect to an Inverter?
Each maximum output capacity size Sunsynk Inverter has a different maximum Solar Panel Array DC Power Input rating.
For example:
— the 5 kW Inverter can receive 6000 Watts (e.g. 10 x 560 Watt Panels) of peak Panel Power
— the 8 kW Inverter can receive 10400 Watts (e.g. 18 x 560 Watt Panels) of peak Panel Power
— the 16 kW Inverter can receive 20800 Watts (e.g. 36 x 560 Watt Panels) of peak Panel Power
Bright Future Solar supplies Solar Panels that can produce 550 to 560 Watts peak power each depending on the brand that Herholdts is stocking and supplying at the best price at any one time.
How much power do typical household appliances consume?
If you are unfamiliar with electricity power measurements then here are some everyday appliance examples for reference:
— A kettle typically consumes 2000 Watts of power.
— A Geyser typically consumes 3000 Watts of power.
Thus (very simplistically), 4 x 560 Watt panels will be required for the Inverter to power the Kettle and 6 x 560 Watts panels will be required for the Inverter to power the Geyser.
More examples: T.V. & decoder (+- 250 Watts), Lights (+- 100 Watts at 10 Watts each), Fridge (+- 200 Watts), Freezer (+- 200 Watts), Microwave (+- 1000 Watts), Toaster (+- 1000 Watts), Hair Dryer (+- 1000 Watts), Vacuum cleaner (+- 1000 Watts), Stove & Oven (+- 1000 to 4000 Watts), Air conditioning (+- 6000 Watts), Pool Pump (+- 1200 to 2500 Watts), Washing machine (+- 300 Watts – unheated)
Note that a Solar Panel with a maximum peak output power of 560 Watts will produce its peak power under optimum Sunny conditions usually between 10am and 3pm.
At others times when the sun is not as directly above the panels and/or when there is cloud cover, the actual power produced per panel will be less than 560 Watts.
How many Solar Panels will be required to provide adequate Solar Panel Array Input Power to meet the power needs of your premises?
We first determine how many appliances you have (essential and non-essential) and what their power consumptions are.
We will then recommend a suitably sized Inverter which will in turn influence and determine the optimum number of Solar Panels.
As a rule of thumb, it is best to get as many Panels as you can, considering:
— Your budget: Solar Panels are by far the cheapest component of your Solar Energy Power System.
— Your Sunsynk Inverter’s maximum power output capacity size and its maximum Solar Panel Array Input Power rating.
— Your available Roof space and/or land space that can accommodate Solar Panels
Advantages of Ground-based aluminium Solar Panel Mounting Structures
Instead of mounting Solar Panels on your roof, one can also construct independently standing ground-based aluminium Solar Panel Mounting Structures.
The structures are securely bolted to concrete blocks and can be erected on level or sloped land separately from your house and/or commercial building.
Independently standing ground-based aluminium Solar Panel Mounting Structures have several advantages over roof mounting:
Optimal Orientation and Tilt: Ground-based Panel mounting systems can be positioned and angled to maximize sun exposure, unlike roofs that most often are not perfectly oriented and angled. This ensures that the panels operate more efficiently throughout the year.
No Roof Space Constraints: Ground-based Panel mounting systems aren’t limited by roof space, allowing larger arrays and more panels.
No Roof Concerns: There’s no need to worry about roof condition, orientation, or material compatibility, which can be limiting factors for roof-mounted systems.
For example: Installing Panels on Asbestos roofs is prohibited.
Expandability: It’s generally easier to add more panels to a ground-based Panel mounting system as you’re not limited by the roof size or shape.
Better Airflow & Cooling: Ground-based Panel mounting systems typically have better air circulation around them, which helps keep the Panels cooler which can result in higher efficiency compared to roof-mounted panels that may trap heat.
Ease of Maintenance: Ground-based Panels are easier to access for cleaning, repairs, or upgrades, which can help maintain their performance and extend their lifespan.
Avoids Roof Shading: Ground mounts eliminate shading from chimneys, trees, or neighboring structures, improving energy production.
These advantages make independently standing ground-based aluminium Solar Panel Mounting Structures an excellent choice for maximizing energy production and efficiency.
If your installation requires Ground Mounts then an independent contractor will have to install the Mounts before the arrival of the Solar Energy System Installer.
If you live in the Garden Route area we can suggest the services on an independent contractor who can build the ground based mounting structures at your premises. Alternatively, if you live in another area then we can make enquiries if you prefer.
Contact Us for more information.
Protective fencing for ground-based aluminium Solar Panel Mounting Structures
Depending on your environment, especially farms and other areas where there may be farm animals (eg. cows, horses, goats, donkeys, etc.) or wild animals (e.g. baboons can be very destructive) it may be prudent to erect a protective fence enclosure around your ground-mounted Solar Panels.
The protective fence enclosure can also serve as a deterrent from vandals and/or opportunistic thieves.
The protective fence enclosure requires:
— 2.8 metre fencing poles that are placed 800 mm in the ground (preferably concreted in place) with 2 metres above ground
— 1.8 metre mesh fencing (diamond mesh or welded mesh)
— Razor wire which is placed along the top of the 1.8 metre mesh fence making the fence + razor wire approximately 2 metres tall.
— 1.8 metre entrance gate or 2 x 1.4 metre entrance gates.
The independent contractor that can install the ground-based mounting structures can also erect a protective Fence Enclosure to protect your ground-based Panels from wild animals and/or farm animals that may inadvertently damage the panels.
Contact Us for more information.
Why is it ideal to at least match the Solar Panel Array Output Peak Power with the maximum power output capacity of your Sunsynk Inverter?
A 16 kW Sunsynk Inverter has a maximum output capacity of 17 500 Watts.
Thus a 16 kW Inverter will require a Solar Panel Array of 31 x 560 Watt Panels (17 360 Watts) to ensure that the Inverter is able to operate near to its full output capacity (17 500 Watts) under optimum Sunny light conditions (usually a sunny cloudless day between 10am and 3pm) without having to use any power from the batteries and/or from Eskom in a hybrid set-up.
This is very useful for running non-essential high power appliances like Air conditioners (typically consumes at least 6 kW of power), pool pumps, etc. that are most typically used during the hot and Sunny day time.
With the Inverters full output capacity available from the Solar Panel Array (under optimum Sunny light conditions), there is more than enough power to run the Air conditioning (6 kW), heat the geyser (3 kW), run 5 kW of additional appliances and still spare 3.5 kW to charge the batteries if required.
This enables the Inverter to charge the batteries at nearer to the Inverters full output capacity optimizing the use of the available bright sunlight… when it is available.
This is very useful on partly to heavily cloudy days where the sunlight brightens and dims randomly.
For example, on a fairly thickly clouded day when the Solar Panel Array is only producing 20% of its maximum output power (20% is 3472 Watts in the example of 31 x 560 Watt Panels) and assuming (for the purposes of explanation) that the premises is using no power…
A Battery bank with for example 31.94 kWh of Storage (2 x 15.97 kWh Batteries), depleted to 50% overnight (in other words 15.97 kWh has been used) will take +- 4.6 hours (276 minutes) to charge to 100% (with 3472 Watts available).
However, if a break in the clouds occurs and the Inverter can charge the Battery bank at 17 360 Watts, then the battery bank will be charged up from 50% to 100% in just 65 minutes… a substantial difference.
This situation often happens on cloudy to partly cloudy days. The bigger the Solar Panel Array the better the system can take advantage of temporary breaks in the clouds to ‘soak’ up as much energy as fast as possible whenever direct sun light is available between 10am and 3pm.
Thus, matching the Solar Panel Array Output Peak Power with the maximum power output capacity of your Sunsynk Inverter ensures the best chances that the Inverter can supply its maximum output power to the premises without using the batteries and that the battery bank will be charged up as fast as possible on cloudy and partly cloudy days.
Why is it ideal to match as closely as possible the maximum Solar Panel Array Output Power with the maximum Solar Panel Array Input Power rating of your Sunsynk Inverter?
Space and Budget permitting it is 100% optimum to match the maximum Solar Panel Array Output Power with the maximum Solar Panel Array Input Power rating of your Sunsynk Inverter.
For Example:
A 16 kW Sunsynk Inverter has a maximum Solar Panel Array Input Power rating of 20800 Watts which will require a Solar Panel Array of 36 x 560 Watt Panels producing 20 160 Watts.
The maximum Solar Panel Array Output Power is referring to the peak rated power of each panel multiplied by the number of panels. In our example that is 560 Watts per panel.
The peak power will only be produced on optimum sunny days most often between 10am to 3pm.
In this example, we use 36 x 560 Watt panels and not 37 x 560 Watts even though 37 x 560 Watt panels will produce 20 720 Watts which is still below the maximum PV Input rating of 20 800 Watts.
The reason for this is that we will require an even number of panels to balance out the Input Voltages when designing the Solar Panel Array configuration.
For example, consider the 16 kW Sunsynk Inverter with a maximum Solar Panel Array Power Input rating of 20800 Watts and 3 MPPT’s each with 2 strings.
In this example:
36 x 560 Watt Panels will have a peak Panel Power output rating of 20 160 Watts.
An example of a Solar Panel Array Configuration using (for example) 36 x 560 Watt Solar Panels
MPPT 1:
String 1: 6 Panels in Series, Voltage: 6 x 49.4 Volts = 296.4 Volts, Current: 13.96A
String 2: 6 Panels in Series, Voltage: 6 x 49.4 Volts = 296.4 Volts, Current: 13.96A
String 1 and String 2 combined in parallel: Voltage: 296.4 Volts, Current: 27.92A
Note that the Total Voltage is safely below the maximum MPPT Voltage rating of 425 Volts and well above the minimum of 150 Volts.
MPPT 2:
String 1: 6 Panels in Series, Voltage: 6 x 49.4 Volts = 296.4 Volts, Current: 13.96A
String 2: 6 Panels in Series, Voltage: 6 x 49.4 Volts = 296.4 Volts, Current: 13.96A
String 1 and String 2 combined in parallel: Voltage: 296.4 Volts, Current: 27.92A
Note that the Total Voltage is safely below the maximum MPPT Voltage rating of 425 Volts and well above the minimum of 150 Volts.
MPPT 3:
String 1: 6 Panels in Series, Voltage: 6 x 49.4 Volts = 296.4 Volts, Current: 13.96A
String 2: 6 Panels in Series, Voltage: 6 x 49.4 Volts = 296.4 Volts, Current: 13.96A
String 1 and String 2 combined in parallel: Voltage: 296.4 Volts, Current: 27.92A
Note that the Total Voltage is safely above the minimum MPPT Voltage rating of 150 Volts and well above the minimum of 150 Volts.
The Solar Panel Array Power output can reduce down to as little as 10% of maximum output especially on rainy thickly clouded days.
On moderately cloudy days with 100% cloud cover and even with no direct sunlight, the Solar Panel Array Power output may still be as high as 60% especially between 10am and 3pm.
Either way, on rainy thickly clouded days or on moderately cloudy days with no direct sunlight, 10% and 60% of a higher maximum Solar Panel Array Power output is still far higher than a much lower maximum Solar Panel Array Power output.
For example on rainy thickly clouded days or on moderately cloudy but 100% cloud cover days:
A Solar Panel Array of 36 x 560 Watt Panels (maximum 20160 Watts) will produce between 2016 Watts (10%) and 12096 Watts (60%)
A Solar Panel Array of 18 x 560 Watt Panels (10 080 Watts) will produce between 1008 Watts and 6048 Watts.
Thus it makes sense to maximise the number of panels depending on your available space (Roof and/or land space) and your budget.
Keep in mind that the panels are by far the cheapest component of the Solar Energy Power System.
Why must one consider surrounding temperature fluctuations when deciding how many Solar Panels can be connected in series per string and per MPPT?
An MPPT has a voltage range usually of 150 Volts (minimum) to 425 Volts maximum.
The MPPT is very sensitive to Voltages exceeding its maximum rating and will most certainly be damaged if the range is exceeded (even by just a few Volts).
The maximum Voltage output of a Solar Panel e.g. 49.4 Volts is measured at 25 degrees Celsius when the panel is under direct noon sunlight at an optimum angle.
The Voltage output of the Solar panel actually increases by 0.26 % / °C for every degree Celsius less than 25⁰ C.
Whilst this does not sound like a lot, consider what can happen on a very cold day should the sun come out from behind the clouds or on a cloudless and very cold day…
For example, a string of Panels connected to an MPPT has 8 Panels and each panel (for example) has a maximum Voltage output of 49.4 Volts and all 8 Panels are connected in Series resulting in an maximum output Voltage of 395.2 Volts (at 25 degrees Celsius under direct noon sunlight).
The 16 KW Inverter’s MPPT has a maximum Voltage input rating of 425 Volts. Thus it seems safe to have 8 Panels in series (?)
However, should the temperature go down from 25⁰ C by 35 Degrees to minus 10⁰ C, the maximum Voltage will increase by 9.1% (0.26% x 35 degrees) on a very cold day whenever the sun is shining directly on the panels.
Keep in mind that the environmental temperature will not affect the number of photons striking the panel when the sun is directly overhead. Thus one can have a very cold day of -10 degrees and the 8 Panels can still ‘over-produce’ Voltage if exposed to direct sunlight.
Thus in this example, the Voltage goes from a very safe 395.2 Volts to 431.16 Volts
The MPPT will probably blow!!
Thus in climates that can experience very low temperatures (even just once in Winter with direct sunlight), considering the example above, it will be best to make strings of not more than 7 Panels with a total Voltage of 345.8 Volts which will then go up (by 9.1%) to 377.26 Volts at minus 10⁰ C which is safely in the MPPT’s voltage Range.
What is the ‘Cloud Enhancement Effect’ on Panel Voltage?
The Cloud Enhancement Effect, also known as the Cloud Edge Effect, can cause significant increases in sunlight intensity.
When sunlight passes through gaps in the clouds, it can become concentrated, leading to a spike in the intensity of light hitting the solar panels.
This can result in temporary Voltage output increases/spikes, often times exceeding the panels rated maximum Voltage output which is based on clear sky conditions, direct midday sunlight and 25 degrees Celsius.
Studies have shown that the Cloud Enhancement Effect can increase sunlight intensity by up to 30% or more for brief periods. This means that even if the sun is behind clouds, the moment it peeks through a gap, the intensity can spike significantly.
Given this, it’s crucial to consider this effect when designing your solar system, especially when deciding how many panels to connect in series. Overloading the inverter can lead to inefficiencies or even damage, so it’s important to account for these potential spikes in voltage output.
In our example of 8 Panels connected in series each with a rated Voltage output of 49.4 Volts totaling 395.2 Volts for the 8 Panels, even a 10% spike in light intensity can increase the Voltage to 434.2 Volts thus overloading the system and tripping the circuit breakers housed in the Inverter itself.
Most of the time, the 8 Panels produce a total Voltage output ranging from 320 to 370 Volts so a 10% spike may just… just make it and be OK.
But a 20 to 30% spike will trip the unit and probably result in damage over time.
One will have to remove the bottom cover of the Inverter and reset the circuit breakers.
It will be far safer to connect only 6 Panels in series per string as per the above example for a 36 x 560 Watt Canadian Solar Panel configuration.
About Current ratings for Circuit Breakers and Fuses
Keep in mind that the Voltage stays the same when two strings are connected in Parallel but the Current doubles.
In our configuration example (above) this results in a potential maximum Current of 27.92 A.
In this configuration with two strings each with 6 Panel in series and the two strings then connected in Parallel, the circuit breaker between this set of two strings and the MPPT to which the two strings are connected to must have a 30 amp fuse.
Although it may be confusing to some, the 16 kW Inverter (in our example) is able to utilize a maximum input Current of 26 Amps per MPPT BUT can safely manage up to 44 Amps of input Current.
Thus the parallel connection producing a maximum of 27.92 Amps is well with safety limits.
Assisting you with determining how many Solar Panels your premises (and your Inverter) may be able to accommodate:
Send us Photographs and approximate measurements for potential Solar Panel mounting roof areas.
OR Send us Photographs and approximate measurements of areas near your premises that may be suitable for the construction of Ground based Solar Panel Mounting Structures.
Send us your Street address or GPS coordinates for Google Earth aerial views of your premises and to determine North and South relative to the potential panel mounting areas.
Note that Bright Future Solar offers Inverters and Batteries for immediate sale via the Bright Future Solar online Shop.
Bright Future Solar also provides reputable Solar Panels procured via Herholdts Solar Equipment wholesalers.
Herholdts procures and distributes reputable panels in huge quantities in an ever changing market and so the brand of panel available and the cost per panel is changing all the time.
If you know how many panels you require or we have assisted you to make a decision then we will send you a quote for that number of panels.
Note that the delivery cost for the panels is at least R100 per panel (and more) depending on the distance from the Herholdts warehouse closest to you.
We will send you a quote with the total cost of the panels as well as the delivery cost.
