10W 12V Epoxy Resin Poly Solar Panel (HCPOWE0007)
Posted: Thu Jan 19, 2017 12:14 pm
This relatively large 360mm x 220mm solar panel has an active photovoltaic cell area of approximately 636.5cm² delivering up to 10 watts of solar power at a maximum voltage of 18V. The panel comes with integrated blocking diode to protect against reverse flow of energy. Colour coded 1 meter fly-leads with handy insulated crocodile clips allow the panel to be conveniently connected to the equipment needing to be powered or charged.
1.Light weight easy carry 0.3KG only
2.Free sun light charge
4.Can be used for trickle charger
5.DIY your camper backpack
6.Diode for anti-reverse charging to battery
7.Nice looking by laminated PCB board with top PET sheet
9.with 1m cable
Product code: HCPOWE0007
Related power 10W
Short circuit current (Isc): 0.54A
Working current (Iop): 0.57A
Output Tolerance: ±3%
Temperature range: -40℃to +80℃
SLA Battery Voltage: 12V
Dimensions (L x W x H): 360mm*220mm*3mm
NET Weight (KG ) 0.3
Why is the amount of current I get from my solar panel lower than the specification?
The amount of energy a photovoltaic cell can produce is directly related to the amount of energy there is in the sunlight reaching it. As an example let's start by making a rough calculation of the panels efficiency:
When the Sun is directly overhead the amount of potential energy it produces is about 137 milliwatts for every square centimeter of area it hits. For this panel the actual area of the cell is about 3.4cm x 2.6cm x 72 cells (rough measurement), which is about 636.5 centimeters squared. This gives the maximum amount of energy that the cell can collect as 87.2 watts if the pannel was 100% efficient. The manufacturer specs this cell at a maximum output power of 10 Watts. This means that the cell is approximately 11.5% efficient. i.e 11.5% of the energy in the sunlight will be converted to electrical energy by the cell. This figure is pretty typical for a photovoltaic cell, most common types of cell usually range between 10 - 20%. Therefore, based on these rough calculations, this seems a reasonable calcultation.
However, the above calculations are based on the maximum possible energy that can be collected from the sun when it is directly above. When taking into consideration the time of day, distance from the equator, and time of year, the sunlight hitting the panel is unlikely to be at this energy level. Let's take for example the UK in mid summer and winter:
In the UK, not being located near the equator, in mid summer, and at high noon we get about 60% (this also varies greatly depending on if you are in Scotland or southern England) of the energy when compared to countries at the equator because the sun is never directly above us, even in mid summer. So based on the efficiency of our panel this means that the maximum amount of energy you can reasonably expect to get from the cell is about 6 Watts, or about 330mA (assuming maximum panel efficency occures at maximum panel voltage).
In winter the sun is significantly lower in the sky, and in mid winter the amount of energy can be only a third of what it is in mid summer. This is because the sunlight has to travel through more of the Earths atmosphere and so gets reflected, scattered, and absorbed by water molecules, dust and other pollutants. Based on the above calculation, a third of the amount of available energy in mid summer is about 2 Watts, or 110mA.