Skip to main content

Solar Projects

Solar energy is free, but harnessing it efficiently can be a challenge, and could take some serious effort. And this may not be possible unless you know all the little secrets that might be required for converting solar energy into lifetime home electricity.

Having a full access to the knowledge regarding how to install and run solar panels at will, how to use battery charger controllers, MPPT units and inverters, could ensure you never have to depend on confusing and costly external inputs.

Now this may be well within your reach.

What you need to do is put a little effort and time in reading the many exclusively researched articles below, related to solar panel electricity management through controllers and inverters, that would help you to master the subject without spending on long and expensive courses.

If you have problems, write them through comments, I'm online 12 hours a day, so you can expect quick replies from me :)

Simple Solar Chargers: 

A few simple solar panel based circuits are listed below, which can be built by any hobbyists, or a school student for converting solar energy into usable electricity.

The designs could be used for charging a battery or operating any small DC load as per the user specifications.

Simple Solar Voltage Regulator
Simple Solar Inverter Circuit
Simplest Solar Battery Charger Circuit
Simple Solar Garden Light
Simple Solar E-Rickshaw
Simple Timer Based Solar Tracker
Design your own Solar Inverter
Solar Pocket LED Lamp
Make this Solar Cooker at Home
PIR Solar Home LED Light
6V Solar Charger with Cut Off
Solar Porch Light with Timer
BJT Based Solar Charger Cut off

MPPT Circuits

MPPT circuits are supposed to be complex with its operating principle. However it's not actually the case. Once you understand the concept, you will realize that an MPPT circuit is all about acquiring an optimized output from the solar panel, where the output power is close to the input power. That is output I x V = Input I x V (95%)

A few customized easy to build homemade MPPT designs are explained below. These could be easily understood and applied for getting the expected results.

Simple MPPT Circuit
How MPPT Works
Difference Between MPPT and Solar Tracker
How to Connect MPPT with Solar Inverter
3 Best Commercial MPPT Designs
Understanding Solar Voltage and Current Specs
Convert an 220V SMPS into an Efficient Solar Charger

How to Configure Solar Panel

Normally a user finds it too confusing when it comes to configuring a solar panel with its home electricity. Technical personals, and manufacturer take the advantage of this confusion and charge high fees from the user for implementing a simple solar panel wiring.

But No more of these confusions, here I will let you learn how to configure any solar panel with any sort of load, whatsoever, and get the most optimal outputs from the configuration.

Moreover you can always contact me and get an instant suggestion or clarification regarding any issues or problems that you may happen to face concerning solar panel installation and wiring.

Calculate Solar Panel, Battery and Inverter Matching Specs
How to Configure a Solar Panel
Using Solar Charger as Water Heater
Changeover Circuit from Solar to AC/AC Adapter
Using as Convex Lens for Focusing Sun Rays
Solar Electricity for an Off-the-grid Living

Solar Inverters/Converters

When we talk about solar panels, an inverter always happens to be an integral part of the system. And with an inverter, a battery becomes another integral part.

Making a solar inverter may appear quite daunting to any newcomer, but you will be surprised to know that it's actually a child's play to build a solar inverter.

Simply because, a solar panel is nothing but a DC source, which just needs to be matched with the inverter for the actions. You will be enlightened more and more as you go through the following expertly researched articles. If you any help, just comment, and I'll get in touch with you!!

Design you own Solar Inverter
3 phase Solar Inverter Circuit

Solar LED

When we are using a device as efficient as a solar panel, we would also want to use a load that's equally efficient. Lights are the prime necessity of every house, and today no form of light can be more efficient than an LED lamp in terms of light intensity and consumption.

Using an LED lamp with a Solar panel can make things extremely favorable and cost effective for any individual who may have installed these two systems for home use.

A battery, a solar panel, and a power LED is all that'd need to install an effective solar LED system in your home....

You can find many related article on this through the following links:

More Circuits Can be Found HERE

Need Help? Please leave a comment, I'll get back soon with a reply!


  1. sir i need a circuit for solar mppt dusk to dawn charge controler for 150w solar panel,dc load out 75w pleae send me

    1. presently i don't have it, will try to publish one soon.

  2. sir i need a circuit for solar mppt dusk to dawn charge controler for 150w solar panel,dc load out 75w pleae send me

  3. hi there Swagatam i have a inverter ups battery charger combo called a bps- 3624 that i want to run only as a inverter with (10x12v 105a/h batteries) conected in 24 v witch is charged with (4x100watt 12V panels) connected 24V with a 30 amp controler but as i was connecting my change over panel i made a short and smoke came out of the inverter, i openend it up and found the inverters on heat sink burned (irf3205)they are marked from Q1 to Q16 and there is also resistors but they are badly burned and i can not see their lines can u please help me

    1. where are these resistors connected?....if these are connected with source pins then you may replace them with 0.1ohms, 10 watt

      if these are gate resistors then replace them with 100 ohms 1/4 watts resistors.

  4. sir i want to make a solar hybrid invertor but i dont know how to use a current comparator circuit

    1. pls provide a detailed explanation about the project.

  5. Hi Swagatam Majumdar,

    While i was just googling electronic circuits i found one video, and it is very tempting.

    I am planning to do the same. In this regards, i need your support.

    Before that

    will it work practically ?

    Please guide...............

    1. I watched the video, it looks interesting but why did the uploader disable comments...because he knows intelligent viewers will pick out the hidden trick and blow it for me it's as usual a fake video.

      However if you could actually try it and give us the feedback, would appreciate it a lot.

  6. what kind of solar panel you r using in ur projects???

  7. Do you have any inverter circuit that applies to these solar panel specs:

    Nominal Power12 (Pnom) = 435 W
    Rated Voltage (Vmpp) = 72.9 V
    Rated Current (Impp) = 5.97 A
    Open-Circuit Voltage (Voc) = 85.6 V
    Short-Circuit Current (Isc) = 6.43 A

    1. you can use the following design with the s few modifications:

      use a transformer with input as 30-0-30V, output as per the needs 220 or 120V
      use BC546 for T1, T2, ....use 10k for R3,4,5,6

  8. sir i need 3phase Solar Inverter circuit please

    1. you can use the following circuits with a solar panel:

  9. Dear sir
    i need to manufacturing solar street lights. so i wants to get full circuit of solar charge controller cum led driver for following specification. panel 75w max. , battery 75w max, LED 9watt/12watt .( output 10v/1050ma and 10v/1400ma)
    (1) load (LED) disconnected when battery discharged less than :10.5v
    (2) Panel input power will be cut off when battery reach at 13.5v
    (3) Panel input will be reconnect when battery reach at 12.5v
    (4) Load on when solar panel input voltage less than 1v
    (5) Load off when solar panel input voltage more than 1v
    if possible i want to make this circuit without using microcontroller and variable resistor. i am ready to pay your fee for this project. you can send me mail on
    Prashant patel

    1. Dear Prashant,

      For one tested sample prototype of the above mentioned unit, you would have to pay an amount of Rs.5000/- (full in advance) and wait for 10 days for the delivery.

      Otherwise you may refer to the following circuit design and build it, it is almost similar to your present requirement:

  10. Hi Swagatam,

    Could you please tell for our solar projects which panel would be better, a monocrystalline or a polycrystalline solar panels ?

    thanks and regards
    S Sarath

    1. Hi Sarath,

      polycrystalline solar panels would be better.

    2. Hi Swagatam,

      What are the advantages of polycrystalline solar pannels?
      Is it only the cost, as i have read that mono crystalline pannels are costly but are more efficient and thus smaller (for same wattage), have more life then polycrystalline pannels?
      But I don't have much practical idea regarding them.
      Please advise.

      thanks and regards
      S Sarath

    3. Hi Sarath,

      I too don't have much practical idea about solar panels, I would suggest you to Google this "monocrystalline v/s polycrystalline solar panels", you will find plenty of info regarding them

  11. hello sir,

    I want to make a solar inverter phone charger for science project, please help me regarding this.
    Also tell me the type of solar panel must be used for the same and of what reading.

    your biggest follower,
    Himanshu grover

    1. Hello Himanshu,


      You can use a 12V/1amp solar panel and the following circuit attached to its output for charging a cell phone:

  12. Hi Sir Swagatam,

    can u guide me if my computation is correct for my solar project,..


    Watt Load 155 Watts
    Hour Running 10 Hours
    Consumed 1550 Watt Hours

    Total Watts Required 1550 Watt Hours
    Sunlight Hours 10 Hours
    Required 155 Watts

    Battery 12 Volts
    Required ≥ 130 Battery AH

    Solar Panel 155 Watts
    Battery Voltage 12 Volts
    Required ≥ 15 Amps

    12 Volts ≥ 155 Watts

    1. Hi Unknown,

      It looks correct except the following
      Solar PANEL

      Total Watts Required 1550 Watt Hours
      Sunlight Hours should be 5 Hours
      Therefore Required = 310 Watts

  13. how to produce e.c. from sound waves some one please help me if you can?

  14. Dear sir,
    Please help me pure sine wave solar inverter circuit diagram.
    Input:- 24 V DC, 168 VA
    Output:- 150 W, 50 Hz sine wave, 220 V AC

    1. Dear Srinjoy, here's one simple design you can try:

      use LM324 for the opamps

  15. Hi Swagatam,
    This is Raju. I need a load limitter circuit. Concept is, If the load is exceeded to the defined load capacity, the power will be discussed to the particular house or room. Can forward the circuit if u have any to my mail ljayarajuatgmaildotcom

    1. Hi Jayaraju, I could not get the following line:

      "....the power will be discussed to the particular house or room"

      please clarify it so that I can understand the application correctly

  16. HI Swagatam,

    First of all you and your blog are awesome……. I really like your blog which taught me a lot of things about electronics. Basically I am an electrical engineer and frankly very new in the field of Electronics.
    I am working on 500 Watt solar project, for which I want to build the pure sine wave inverter. Can you please suggest a working solar inverter circuit diagram along with the component details.
    Input:- 12 V DC,
    Output:- 500 W, 50 Hz sine wave, 220 V AC

    Thanks a lot in advance.

    1. Thanks so much Gokul,

      you can try the following circuit, since it would allow you to get a pure sine wave output:

  17. HI Swagatam,

    Thanks a lot for link. I have started working on buidling the pure sinewave inverter as per your link. and I have some queries related to this project:
    1. what is type and voltage rating of capacitor C1 & C2 (ceramic or electrolytic)?
    2. Do we have any alternatives for BDY29 as this is not available is Pune.

    Gokul Bairagi

    1. Thanks Gokul,

      both are ceramic capacitors, for the transistors you can try 2N3055 or TIP35.

  18. I am a student doing diploma in electrical and electronics in one of the university in kenya.I am intrested in solar project project for my final year .Can you assist in getting two projects for me.thanks in advance

    1. please specify the details of your requirement.

  19. sir i need 24 v , 100 ah battery(12v 100ah x 2 in series) charger circuit to charge from solar. I have an arrangement of 1 kwp solar pannel (which can give 35v max. , 28 A max. if 4 panel in parallel). I want to make cost effective 1kw solar ups.

    1. Ashique, since your panel specs are very much compatible with your battery specs I think you can connect the panel output directly with the batteries through a 50amp ammeter.

      you can use just two panels and comfortably allow 14amp for the charging purpose

  20. hello sir , i am a big fan of your works can you help me get a circuit flow or an idea aqbout solar charging station

    1. Hell Diana, please explain your requirement elaborately with specifications

  21. Hello sir

    I am currently working on a solar project that charges a 12 V, 7 Ah lead acid battery.
    From this battery I would like to charge a smart phone through a USB port situated after a converter circuit.
    The smart phone requires 5 V and a max of 2000 mAh.

    The idea I have is to build a DC/DC buck converter that converts the 12 V to 5 V with a very high efficiency.
    I currently have a IRF3205 power FET and a MIC5014 Mosfet driver that I want to use. I have a Arduino nano that can be used too.

    Would you please help me in this regard with a type of design because my research has led nowhere.

    Thank you

    1. Hello Francoise, I think you should try the following circuit concept, but it does not incorporate the parts which you have mentioned

  22. good day sir,I have many question to ask and they are:what component in inverter circuit determines 12volt input and 24volt input,what and what determines the watt of an inverter and how can one increase it

    1. Hi Clemo, voltage supply is not determined by the circuit, rather it's the other way round...the circuit must be configured and rated as per the if your input is 12V then the transistors and the capacitors must be rated to work comfortably with this voltage, and with 24V the parts will need to be further upgraded to match this supply and so on.

    2. in an inverter the transformer wattage and the battery AH can be used for determining the max delivering capacity of the inverter

  23. Hi Swagat,

    I am looking for a developing a circuit using solar power to water my terrace plants.

    Concept : using solar panel we will charge a battery during the day. Using the battery power with small (portable fountain) motor (available on ebay will water the plant for 5 minutes after every 4-5 hours ... 3 times a day.

    Few things I found on ebay, I am not sure if we can use it..



    3. Some rechargable battery of 6Volts

    Could you please guide?


    1. Hi Raj,

      you will just need a 12V or 6V water valve which can be powered via a programmable timer as explained in this article:

      the whole system could be powered directly via a suitably rated solar panel.

      battery may not be required....the plant can be watered 3 time during day and left unwatered during night.

      If possible I'll try to update the concept in a new article

  24. Dear sir,
    I want to make a charge controller of 10Amp with the help of using Op-Amp ic. I have also visited your post the model batter one or any other model is there.

    1. Dear bhanu, the circuit is good but not yet confirmed practically, instead you can try the following one:

      adjust R8/R9 for customizing the output volatge

  25. Dear Sir,I have a MPP 4048ms 5kv invertor.Am failing to charge the batteries when the solar panel wires go through the invertor but when I connect them direct to the batteries am able to charge the batteries.After charging them this way I will reconnect and use the invertor through the mains without problems and with no fault icon.What could be the problem?.

    1. Dear Nevieg, the problem could be inside the changeover relay section of the inverter, you will have to open the inverter and check how the solar input is getting linked with the battery through a relay changeover section...examine this and make sure it correctly connects the panel supply with the battery.


Post a Comment