Electronic Tips: Photovoltaic Panel & Charge Control
Electronic Rudiments: Photovoltaic Panel & Charge Controler
If you’re looking for an Easy-To-Use, regenerative energy source nowadays 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, for example, charge up a battery. Let’s find out. If we have a closer look at this 100 Watt solar panel solar panel we can see that it consists of individual solar cells those basically make up all commercially available solar panels and of course you can buy such cells online as well after soldering a tap water to the prawns SD – terminal empty bag SD plus terminal we can use a multimeter to measure voltage up around 0.
5 volts when light hits the cell surface that is pretty much the maximum output voltage of one cell which is also the reason why a solar panel connects many of those cells in series in order 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 point 3 volts but if you are not thinking about soldering many bare solar cells in series instead of buying a proper solar panel to save a bit of money then it is noteworthy that those cells are extremely brittle and thus can be hard to work with
so having a proper housing for the cells is definitely worth the money now if we have a closer look at the smaller solar panel we can see it there consists of 12 cells in series but creating such a serious connection also has one big negative side effects just imagine that the cloud could partly prevent lights to get the complete surface of the solar cells that 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 outputs would decrease drastically as an example we can hook up a five millimeter red LED which draws 3.
8 million from the solar panel and thus creates 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 million at an output voltage of 1.71 volts which equals an output power of 3.8 million what’s that means the power decreased by 43% while the surface area are only degrees by 17% that is terrible to solve this problem we could add so-called bypass diodes in parallel to each cell so that current could flow through it instead of the higher resistance solar cell obviously with panels this smaller this does not make much sense but if we take a look inside the junction box of the 100 watt panel we can actually see two diodes those are placed in between behalf of the solar cells empty plus and minus terminal of course this is not the ideal solution but through the two diodes the panel can uphold the power outputs if one half of the panel is starting by clouds or something similar another kind of diode you often see here are
so called blocking diodes and are used when solar panels are connected in parallel in order to decouple them from one another and prevent reverse current flow through them and now that we know how solar panels are wired up it is time to use different loads to test out their power output potential but to lower your optimism right from the start we will probably never get 100 watts from 100 tunnel since those characteristics were determined under so-called STC’s aka standard test conditions those includes any radians of 1,000 watt per square meter a solar cell temperature of 25 degrees Celsius and an am value of 1.
5 which means that the sunlight travel to an air mass of 1.5 times D value up the atmosphere with my 0.6 watt panel here for example I achieve no power of 16 point 5 millivolts with a green LED and output power of 13 point 2 millivolts move a blue LED and an output power of 9.
5 milliwatts with red LED but why does the output voltage vary that much depending on what kind of load I attach we can find the reason by having a look at lease implied equivalent circuit diagram of a solar cell if no load is attached so an open circuit it acts like the constant current source that lets the current flow through diodes which therefore create the characteristic cell voltage of around half of alts parallel to that we got a resistor which represents the power losses caused by the semiconductor material defects and at the end we got a series resistor which represents the power losses two wires terminal connections and
so on if we now add a load to the cell the current from the constant current source device itself and creates more complicated electrical Network but what we know for certain is that by varying the load on the outputs we should be able to find an optimum at which we can draw the most power from the cell so I got myself my DIY power logger hooked up the solar panel were five kilo ampere and Charmander loads inserted a micro SD card and started slowly decreasing the resistance of the loads while simultaneously D constantly changing voltage and current values we’re saved on the SD cards afterwards I imported the acquired data into Excel and created a suitable XY diagram after printing it out and connecting the dots to one another we can see two characteristic points first off the open circuit voltage where no current flows empty short-circuit current where there’s almost no voltage those values are pretty always mentioned on a solar panel but what is also mentioned on my solar panel is the NTP voltage and current nppes stands for maximum power points which is not visible in my diagram so forth
so I multiplied the current and voltage values and added a power line in the diagram which makes 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 so load resistance of 1100 ohms now of course you don’t want to simply add a resistor book the required value to the outputs and be happy about that you can heat it up the most efficient way you usually want to charge up a battery that is where we can use charge controllers the best ones of this kind of
so-called MPPT ones or maximum power point tracking ones those usually utilize some kind of switching converter to act as the ideal MPP loads and thus a charge of the battery other more inefficient kinds simply use PWM to charge of the battery but they do not try to find the MPP and thus can decrease the efficiency of up to 40% and with that being said you already know quite a bit about solar panels and how to use them properly if you learned something new don’t forget to Like share and subscribe stay creative and I will see you next time if you are looking for easy-to-use regenerative energy source nowadays then your best bet is to do those 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 outputs 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 panel we can see that it consists of individual solar cells those basically make up all commercially available solar panels and of course you can buy such cells online as well after soldering a tap water to the prawns SD – terminal empty bag SD plus terminal we can use a multimeter to measure voltage up around 0.
5 volts when light hits the cell surface that is pretty much the maximum output voltage of one cell which is also the reason why a solar panel connects many of those cells in series in order 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 point 3 volts but if you are not thinking about soldering many bare solar cells in series instead of buying a proper solar panel to save a bit of money then it is noteworthy that those cells are extremely brittle and thus can be hard to work with
so having a proper housing for the cells is definitely worth the money now if we have a closer look at the smaller solar panel we can see it there consists of 12 cells in series but creating such a serious connection also has one big negative side effects just imagine that the cloud could partly prevent lights to get the complete surface of the solar cells that 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 outputs would decrease drastically as an example we can hook up a five millimeter red LED which draws 3.
8 million from the solar panel and thus creates 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 million at an output voltage of 1.71 volts which equals an output power of 3.8 million what’s that means the power decreased by 43% while the surface area are only degrees by 17% that is terrible to solve this problem we could add so-called bypass diodes in parallel to each cell so that current could flow through it instead of the higher resistance solar cell obviously with panels this smaller this does not make much sense but if we take a look inside the junction box of the 100 watt panel we can actually see two diodes those are placed in between behalf of the solar cells empty plus and minus terminal of course this is not the ideal solution but through the two diodes the panel can uphold the power outputs if one half of the panel is starting by clouds or something similar another kind of diode you often see here are
so called blocking diodes and are used when solar panels are connected in parallel in order to decouple them from one another and prevent reverse current flow through them and now that we know how solar panels are wired up it is time to use different loads to test out their power output potential but to lower your optimism right from the start we will probably never get 100 watts from 100 tunnel since those characteristics were determined under so-called STC’s aka standard test conditions those includes any radians of 1,000 watt per square meter a solar cell temperature of 25 degrees Celsius and an am value of 1.
5 which means that the sunlight travel to an air mass of 1.5 times D value up the atmosphere with my 0.6 watt panel here for example I achieve no power of 16 point 5 millivolts with a green LED and output power of 13 point 2 millivolts move a blue LED and an output power of 9.
5 milliwatts with red LED but why does the output voltage vary that much depending on what kind of load I attach we can find the reason by having a look at lease implied equivalent circuit diagram of a solar cell if no load is attached so an open circuit it acts like the constant current source that lets the current flow through diodes which therefore create the characteristic cell voltage of around half of alts parallel to that we got a resistor which represents the power losses caused by the semiconductor material defects and at the end we got a series resistor which represents the power losses two wires terminal connections and
so on if we now add a load to the cell the current from the constant current source device itself and creates more complicated electrical Network but what we know for certain is that by varying the load on the outputs we should be able to find an optimum at which we can draw the most power from the cell so I got myself my DIY power logger hooked up the solar panel were five kilo ampere and Charmander loads inserted a micro SD card and started slowly decreasing the resistance of the loads while simultaneously D constantly changing voltage and current values we’re saved on the SD cards afterwards I imported the acquired data into Excel and created a suitable XY diagram after printing it out and connecting the dots to one another we can see two characteristic points first off the open circuit voltage where no current flows empty short-circuit current where there’s almost no voltage those values are pretty always mentioned on a solar panel but what is also mentioned on my solar panel is the NTP voltage and current nppes stands for maximum power points which is not visible in my diagram
so forth so I multiplied the current and voltage values and added a power line in the diagram which makes 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 so load resistance of 1100 ohms now of course you don’t want to simply add a resistor book the required value to the outputs and be happy about that you can heat it up the most efficient way you usually want to charge up a battery that is where we can use charge controllers the best ones of this kind of so-called MPPT ones or maximum power point tracking ones those usually utilize some kind of switching converter to act as the ideal MPP loads and thus a charge of the battery other more inefficient kinds simply use PWM to charge of the battery but they do not try to find the MPP and thus can decrease the efficiency of up to 40% and with that being said you already know quite a bit about solar panels and how to use them properly if you learned something new don’t forget to Like share and subscribe stay creative and I will see you next time
