What is MPPT Solar Controller?
1.What is MPPT Meaning ?
MPPT Meaning maximum power point tracker.
a high efficiency DC to DC converter that presents an optimal electrical load to a solar panel or array and produces a voltage suitable for the load.most commonly for a solar panel or array, and converts the power to a voltage or current level which is more suitable to whatever load the system is designed to drive.
Panel tracking - this is where the panels are on a mount that follows the sun. The most common are the Zomeworks and Wattsun. These optimize output by following the sun across the sky for maximum sunlight. These typically give you about a 15% increase in winter and up to a 35% increase in summer.
This is just the opposite of the seasonal variation for MPPT Solar Controller. Since panel temperatures are much lower in winter, they put out more power. And winter is usually when you need the most power from your solar panels due to shorter days.
Maximum Power Point Tracking is electronic tracking - usually digital. The charge controller looks at the output of the solar panel, and compares it to the battery voltage. It then figures out what is the best power that the panel can put out to charge the battery. It takes this and converts it to best voltage to get maximum AMPS into the battery. (Remember, it is Amps into the battery that counts). Most modern MPPT's are around 93-97% efficient in the conversion. You typically get a 20 to 45% power gain in winter and 10-15% in summer. Actual gain can vary widely depending weather, temperature, battery state of charge, and other factors.
Grid tie systems are becoming more popular as the price of solar drops and electric rates go up. There are several brands of grid-tie only (that is, no battery) inverters available. All of these have built in MPPT. Efficiency is around 94% to 97% for the MPPT conversion on those.
2.What Advantage of MPPT solar controller?
In any applications which PV module is energy source, MPPT solar controller is used to correct for detecting the variations in the current-voltage characteristics of solar cell and shown by I-V curve.
MPPT solar controller is necessary for any solar power systems need to extract maximum power from PV module; it forces PV module to operate at voltage close to maximum power point to draw maximum available power.
MPPT solar controller allows users to use PV module with a higher voltage output than operating voltage of battery system.
For example, if PV module has to be placed far away from charge controller and battery, its wire size must be very large to reduce voltage drop. With a MPPT solar controller, users can wire PV module for 24 or 48 V (depending on charge controller and PV modules) and bring power into 12 or 24 V battery system. This means it reduces the wire size needed while retaining full output of PV module.
MPPT solar controller reduces complexity of system while output of system is high efficiency. Additionally, it can be applied to use with more energy sources. Since PV output power is used to control DC-DC converter directly.
Frequently Asked Questions
-
QUESTION:
Solar Charge Controller Circuit for 20A,12V?
Solar Charge Controller Circuit for 20A,12V with Low Voltage Disconnect (LVD), Temperature compensation.-
ANSWER:
what is the question?.
-
-
QUESTION:
can anyone tell me any site where i can get the details of a solar charge controller including its circuit?
the charge controller must be based on 'atmega' series microcontroller-
ANSWER:
http://homepower.com/article/?file=HP70_pg40_KirkgaardAlthough this circuit uses a 555 timer you can use the functionality of a micro controller to monitor PV and battery voltage with the ADC or comparator hardware in the uC.
An ATmega is probably over kill for such a basic application you could do with an 8 pin ATtiny25 unless you plan on adding additional functionality such as a user interface etc.
In fact here is an ATtiny13 based charger..
http://blog.makezine.com/archive/2006/08/improved_solar_charged.htmlAtmel offers the following application note on a battery charger. You should be able to incorporate elements into your own design.
One advantage of the Atmel AVR 8 bit microcontroller design is that they all use the same core. Its only differences in hardware between the various uC's so you show have little trouble in porting over code from one AVR type to another.
So the MAKE ATtiny13 is indirectly based on an Atmega by the use of common core design.
-
-
QUESTION:
if the open circuit volt is 21.5 on a solar panel do you need a charge controller?
I purchased 40 watt Solar Panel Battery Charger Kit with a Maximum Power Voltage of 17.5V
Maximum Power Current of 2.29A with Open Circuit Voltage of 21.5V, and have a brand new deep cycle battery and don't want to hurt it by overcharging it should I have a Charge Controller on the system?
more info on the kit can be found a the Source here: tektrumcorp.com/solar_panels-
ANSWER:
Solar controller is a must for a solar power system. It will smooth voltage and improve efficiency, also has over-charger protection circuit and many other protection function to protect your panel and battery from damage.
-
-
QUESTION:
is a 40 watt solar battery kit fitted with a battery protection circuit to prevent overcharging of batteries?
Is a 40 watt Solar Panel Battery Charger Kit with a Maximum Power Voltage of 17.5V
Maximum Power Current of 2.29A with Open Circuit Voltage of 21.5V, fitted with a battery protection circuit to prevent overcharging of batteries?
Or is it recommended to have a Solar Power Charge Controller?-
ANSWER:
Hey Dave, it depends on the, "Kit," you are speaking of, but generally, no, they do not have a circuit to prevent overcharging batteries. This would be the same as a charge controller. I don't know which kit you are speaking of, most manufacturers make several sizes of them. Kyocera has a 40 watt kit with a panel, mounting hardware, cables and connectors. Most panels today do have something called, "Bypass Diodes" installed. A diode is nothing more than an electrical check valve, allowing current to flow in one direction, toward the battery, but not the other. This prevents the battery from discharging into the panel at night.There are instances where you do not need a charge controller. In short, if the panels maximum current rating, called short circuit current, in amps, is no more than 2% of the battery banks amp hour capacity, then a charge controller is not needed. We have two installations here that work that way. Our small home system which provides 12 volt power for cabinet lights, garden lights, and some small 12 VDC electronics in the home uses 4 golf cart batteries wired for 12 volts. This gives us an amp hour capacity of 440 amp hours. Since our 3 panels add up to a maximum of 8.2 amps, well below 2% of the 440 AH rating of the battery, we do not use a charge controller. It has worked well for over 11 years now. The only thing we have to do is make sure the batteries are well watered each month, particularly in warm weather.
There is an excellent book on the subject at your local library, called, "The Complete Battery Book," by Richard Perez. If you pick it up, just pay attention to the chapters on flooded lead acid batteries, which are almost always the type used in solar applications. Richard also happens to be the founder and edtior of Home Power Magazine, a periodical that gets into the nuts and bolts of home grown energy. I recommend subscribing if you are really going to tinker with this technology. You'll find great articles and ads for exactly what you are trying to get into. Some other links are posted below.
Whatever panel you end up with, if it doesn't have diodes or a charge controller, you can get diodes at Radio Shack pretty inexpensively. If the panel is not rated over 4 amps, just get the 6 amp silicone diode, for about 89 cents, and put it right in the junction box on the back of the panel. Make sure the positive output of the panel is first routed through this diode before going to the battery. Hook it up when the sun is out, and see if the battery is getting a charge. If not, you probably have it in backwards, just turn it around. That's all the charge controller we have on our little system, one diode in the back of each panel.
If you do subscribe to Home Power, you can use their online search engine to look up old articles. Back in 2000 they were so taken with our low cost ultra simple system that they ran an article on it. Use the websites search to look for Small System First if you want to check it out. Good luck Dave, and take care, Rudydoo
-