# Harnessing the Power of Solar Panels: A Comprehensive Guide

If you're looking for an easy-to-use, regenerative energy source today, then your best bet is to utilize solar panels. By simply shining light on them, they can create an output voltage that is capable of powering small loads or even bigger ones if we increase the size of the solar panel.

But how can we reach their maximum power output? And how do we have to wire them up to charge up a battery? Let's find out.

## Understanding Solar Cells

A 100 Watt solar panel, for example, consists of individual solar cells. These cells basically make up all commercially available solar panels and can be bought online as well after soldering a tap water terminal onto the SD -terminal empty bag SD plus terminal. We can use a multimeter to measure voltage, which is around 0.5 volts when light hits the cell surface, which is pretty much the maximum output voltage of one cell.

This means that a solar panel connects many of those cells in series to increase the output voltage. My 100 Watt panel for example connects 36 cells in series to create an open-circuit voltage of around 14.3 volts. However, if you're not thinking about soldering many bare solar cells in series instead of buying a proper solar panel to save a bit of money, it's noteworthy that those cells are extremely brittle and thus can be hard to work with.

## Designing Solar Panels for Maximum Power Output

If we have a closer look at the smaller solar panel, we can see that it consists of 12 cells in series. Creating such a serious connection also has one big negative side effect - just imagine that the cloud could partly prevent light from getting to the complete surface of the solar cells, which means that one part of the serious action now features much higher resistance and since current meets the flow to all the cells, the power output would decrease drastically.

For example, we can hook up a five millimeter red LED which draws 3.8 milliamps from the solar panel and thus creates an output voltage of one point seven six volts which equals an output power of six point seven million watts. But if I cover the last two cells of the panel so one sixth of the complete surface, the LED only draws 2.2 milliamps at an output voltage of 1.71 volts which equals an output power of three point eight million what's that means the power decreased by 43% while the surface area are only degrees by 17%.

## Solving the Problem with Bypass Diodes

To solve this problem, we could add so-called bypass diodes in parallel to the solar panels. This is a common solution used in many solar panel systems.

## Maximizing Power Output Using Load Resistance

We can also maximize power output by varying the load resistance on the solar panel. By slowly decreasing the resistance of the loads while simultaneously changing voltage and current values, we're able to find an optimum at which we can draw the most power from the cell.

I got myself my DIY power logger hooked up to the solar panel, with five kilo ampere and Charmander loads inserted into it. I started slowly decreasing the resistance of the loads while simultaneously changing voltage and current values on the SD card. After printing out the data in Excel and creating a suitable XY diagram, we can see two characteristic points - first off the open-circuit voltage where no current flows, and short-circuit current where there's almost no voltage.

## Finding the Maximum Power Point

The point of interest is also known as the NPP (maximum power points) voltage and current, which is not visible in my diagram. However, by multiplying the current and voltage values and adding a power line to the diagram, we can make our maximum power point easy to find this point equals an output voltage of around four point four volts and the current of four milliamps.

## Using Charge Controllers for Efficient Charging

Now that we know how to maximize power output from solar panels, we can use charge controllers to efficiently charge up batteries. The best ones are so-called MPPT (maximum power point tracking) controllers, which utilize some kind of switching converter to act as the ideal MPP loads and thus a charge of the battery.

However, not all charge controllers do this, and more inefficient kinds simply use PWM to charge the battery but they do not try to find the MPP and thus can decrease the efficiency of up to 40%.

## Conclusion

By understanding solar cells, designing solar panels for maximum power output, using bypass diodes, maximizing power output using load resistance, finding the maximum power point, and using charge controllers for efficient charging, you already know quite a bit about solar panels and how to use them properly.

WEBVTTKind: captionsLanguage: enIf you're looking for an Easy-To-Use, regenerative energy source nowadaysthen your best bet is to utilize solar panels.By simply shining light on them, they can create an output voltage that is capable of powering small loadsor even bigger ones if we increase the size of the solar panel.But how can we reach their maximum power output?And how do we have to wire them up to, for example,charge up a battery.Let's find out.If we have a closer look at this 100 Watt solar panelsolar panel we can see that it consistsof individual solar cells thosebasically make up all commerciallyavailable solar panels and of course youcan buy such cells online as well aftersoldering a tap water to the prawns SD -terminal empty bag SD plus terminal wecan use a multimeter to measure voltageup around 0.5 volts when light hits thecell surface that is pretty much themaximum output voltage of one cell whichis also the reason why a solar panelconnects many of those cells in seriesin order to increase the output voltagemy 100 watt panel for example connects36 cells in series to create an opencircuit voltage of around 14 point 3volts but if you are not thinking aboutsoldering many bare solar cells inseries instead of buying a proper solarpanel to save a bit of moneythen it is noteworthy that those cellsare extremely brittle and thus can behard to work with so having a properhousing for the cells is definitelyworth the money now if we have a closerlook at the smaller solar panel we cansee it there consists of 12 cells inseries but creating such a seriousconnection also has one big negativeside effects just imagine that the cloudcould partly prevent lights to get thecomplete surface of the solar cells thatmeans that one part of the seriousaction now features much higherresistance and since current meets theflow to all the cells the power outputswould decrease drastically as an examplewe can hook up a five millimeter red LEDwhich draws 3.8 million from the solarpanel and thus creates output voltage ofone point seven six volts which equalsan output power of six point sevenmillion watts but if I cover the lasttwo cells of the panel so one sixth ofthe complete surface the LED only draws2.2 million at an output voltage of 1.71volts which equals an output power of3.8 million what's that means the powerdecreased by 43% while the surface areaare only degrees by 17% that is terribleto solve this problem we could addso-called bypass diodes in parallel toeach cell so that current could flowthrough it instead of the higherresistance solar cell obviously withpanels this smaller this does not makemuch sense but if we take a look insidethe junction box of the 100 watt panelwe can actually see two diodes those areplaced in between behalf of the solarcells empty plus and minus terminal ofcourse this is not the ideal solutionbut through the two diodes the panel canuphold the power outputs if one half ofthe panel is starting by clouds orsomething similar another kind of diodeyou often see here are so calledblocking diodes and are used when solarpanels are connected in parallel inorder to decouple them from one anotherand prevent reverse current flow throughthem and now that we know how solarpanels are wired up it is time to usedifferent loads to test out their poweroutput potential but to lower youroptimism right from the start we willprobably never get 100 watts from 100tunnel since those characteristics weredetermined under so-called STC's akastandard test conditions those includesany radians of 1,000 watt per squaremeter a solar cell temperatureof 25 degrees Celsius and an am value of1.5 which means that the sunlight travelto an air mass of 1.5 times D value upthe atmosphere with my 0.6 watt panelhere for example I achieve no power of16 point 5 millivolts with a green LEDand output power of 13 point 2millivolts move a blue LED and an outputpower of 9.5 milliwatts with red LED butwhy does the output voltage vary thatmuch depending on what kind of load Iattach we can find the reason by havinga look at lease implied equivalentcircuit diagram of a solar cell if noload is attached so an open circuit itacts like the constant current sourcethat lets the current flow throughdiodes which therefore create thecharacteristic cell voltage of aroundhalf of alts parallel to that we got aresistor which represents the powerlosses caused by the semiconductormaterial defects and at the end we got aseries resistor which represents thepower losses two wires terminalconnections and so on if we now add aload to the cell the current from theconstant current source device itselfand creates more complicated electricalNetwork but what we know for certain isthat by varying the load on the outputswe should be able to find an optimum atwhich we can draw the most power fromthe cell so I got myself my DIY powerlogger hooked up the solar panel werefive kilo ampere and Charmander loadsinserted a micro SD card and startedslowly decreasing the resistance of theloads while simultaneously D constantlychanging voltage and current valueswe're saved on the SD cards afterwardsI imported the acquired data into Exceland created a suitable XY diagram afterprinting it out and connecting the dotsto one another we can see twocharacteristic points first off the opencircuit voltage where no current flowsempty short-circuit current wherethere's almost no voltagethose values are prettyalways mentioned on a solar panel butwhat is also mentioned on my solar panelis the NTP voltage and current nppesstands for maximum power points which isnot visible in my diagram so forth so Imultiplied the current and voltagevalues and added a power line in thediagram which makes our maximum powerpoint easy to find this point equals anoutput voltage of around four point fourvolts and the current of four milliampsso load resistance of 1100 ohmsnow of course you don't want to simplyadd a resistor book the required valueto the outputs and be happy about thatyou can heat it up the most efficientway you usually want to charge up abattery that is where we can use chargecontrollers the best ones of this kindof so-called MPPT ones or maximum powerpoint tracking ones those usuallyutilize some kind of switching converterto act as the ideal MPP loads and thus acharge of the battery other moreinefficient kinds simply use PWM tocharge of the battery but they do nottry to find the MPP and thus candecrease the efficiency of up to 40% andwith that being said you already knowquite a bit about solar panels and howto use them properly if you learnedsomething new don't forget to Like shareand subscribe stay creative and I willsee you next time