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How Much Watts Solar Panel Do You Need for Home Appliances?

How to Select the Proper Solar Panel Rating for Household Appliances?

If you are going to install a solar panel system (off grid or on grid) and want to find the exact amount of wattage and solar panel rating, you can do it easily by the following simple method. The solved example and explanation are as follow.

Suppose we want to power up four lights each of 15 watts and a fan of 60 watts and we need to use these 4 lights and 1 fan for 4 hours every day. So first, we will calculate total watts usage.

Required Load in Watts

PTotal= (4 x 15W) + 60W = 120 Watts.

This is our daily load per hour in watts we need to power up by solar panels.

We Need it for 4 Hrs Daily

Now, we need a continuous power supply for 4 hours a day by solar panel to the load.

Therefore, multiply 120 Watts with 4 hours.

PDaily = 120 W x 4 Hrs = 480 Watt Hours per day.

Sunshine = 6 Hrs

We are going to use 480 Watts daily for 4 hours. Let’s say we are having a complete sunshine for 6 hours each day.

Now we divide 480W by 6 hours to get the final rating of solar panel in watts. This way, we will get hourly power charge that we need for electrical appliances.

Rating of Solar Panel

PHourly = 480 W / 6 Hrs = 80 W / H

So you need a 80 watt solar panel.

Its mean, you need 480 watts for 4 hours where 80W solar panel will produce 480 Watts as sunshine is 6 hours. To know the battery bank, inverter and charge controller size for this system, see the link in the foot-note.

How Much Watts Solar Panel You Need for Home Appliances

Key Point:

The above calculations are based on Ideal case. Therefore, it is recommended that always choose a panel some bigger in rating than we need. Because when solar panel charges the battery, there is wastage of power due to losses as well.

Note: Don’t miss the following detailed article about solar panel installation where we have discussed the required number of solar panels, its rating, battery size and charging time, series and parallel connection of solar panels, rating of charge controllers, UPS/inverter size and rating etc with solved examples.

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  1. We have 10 PV panel rating 270 watt each.
    Volt = 24 and I = 6 amp each solar panel.
    My home total load is 2500 watt and we want 3hrs backup.
    please help on following;
    Inverter rating =?
    Batteries Capacity and its connection=?
    Connectivity of Solar panels i.e series or parallel?

    1. You would need an inverter of 24V, 5 kVA capacity with an inbuilt 100A charge controller.

      If you would like to run full load (2500W) on a backup of 3 hours, you would need four no.s of 12V, 200Ah batteries. A series parallel combo giving you an output of 24V, 400 Ah. Two each in series, and the two sets in parallel.

      As it looks like an off grid connection. You need to connect all the panels in parallel using branch connectors and ensure that the final panel output Voltage is 24V. Do not worry about the current. The charge controller will handle it.

        1. Since it is off grid and only 3hours back up 5 panels may be sufficient. 3.5 ka with charge controller and 4 no. Of 200ah batteries are required.

    2. Hi, according to your load you need an inverter minimum 3KW maximum 5KW,
      and your need a backup pf 3 hours for that’s you need atleast 3 dry gell batteries of 200AH, or 6 batteries of 100AH.

    3. You need to connect all panels in parallel then your panel output will be 2700 watt 24 volt, for this you need an inverter of
      3 Kilo Watt. Battery each 12 v, 180 Amps need to be connected in series. In series positive battery terminal connected with negative terminal and in parallel same polarity terminal are connected together.

    4. Inverter rating = 3.25 KVA
      Batteries Capacity = 1000AH
      Connectivity of Solar panels and battery (i.e series or parallel) depending upon the inverter input voltage and current

    5. You will need 3 or 4kw inveter 48v and please add two more panel to make 12 so you can connect 3 panels in parallel and the arrays of 3 in series (72v 18a). At least 4 units of 12v 200ah batteries connected in series and parallel for 24v connection ( this will give you 24v 400ah) since you didn’t mentioned the no of hours of sunlight. Look for a charge controller that can accommodate 3,200 watts on 48v connection or better still go for Epever 8415 charge controller.

      1. I have a grape solar kit and I did everything I don’t understand the DC load can I cut an extension cord or even a cable cord so the wires put them in the DC load to run a coffee pot or refrigerator 400 watts inverter is a thousand and the control panel where the DC load is

  2. Your website is the most comprehensive i have ever found. You explain every complex electrical topics in simple words and the website is so simple yet user friendly.

  3. I have a 3 Phase 250 Watt , installed capacity load, which needs to run 24 x 7. The average sunshine is 4.9 hours in a day. What should be the sizing of my Solar Panel, Battery &Inverter.

    1. Panels required – two panels 12V, 250 W

      Inverter – 750 VA with 30 A charge controller

      Battery – one 12V, 150 Ah battery

      If you run 500W load, you get a backup of 2.3 hours
      400 W load – 3 hours backup
      300 W load – 4 hours backup
      200 W load – 6 hours backup
      100 W load – 11 hours backup

    2. Hi, according to your load of 500W you need atleast 3 solar panels of 265W or any other combination of solar panels providing a generation round about 1000W, for this purpose you need an inverter of 1.2KW atleast,
      For backup you need atleast 2 dry gell batteries of 100AH it will give you a backup of almost 4 hours in case of fully charged…

  4. Dear Moderator, I intend to use 12 pieces of 2v 500ah batteries, 24v 3000kva inverter to power my house, how many 250w panels and charge controller do I need to install for efficient charging.

  5. And then you need 100% sunshine (no clouds and summertime) on that 50W panel. Which delivers 50 W-hours. No way you can run those lights at the same time.

  6. Dear Electrical Technology Moderator,

    I read your article on solar installation at home. it was very useful for me thank again for the article.

    i want to know one thing, in your article you calculate the load of 800 watt and ask for 6 panels for of 20 A for battery charging and 10 A for direct load. But i have a question that in home every time we does switch on 800 watt load e.g we require on 100 watt in the morning only one or two lights or fan. the the solar panel produce the 30 A current. Hence the load is only 100 watt .

    is solar panel give the excess current to the battery or inverter or it raise the high output voltage from the inverter.

    please guide in this regard

  7. Sir deep freezers usually consume 300 to 700 watts as you know on my deep freeze’s name plate watts are not mentioned but current is 1.3Amps and washing machine i think can use 500 max, also tell me which type of UPS should i use 12v, 24v, 36v or 48v I can make UPS at home
    And also have a 36v 2kv UPS an I have made it assuming 300 watt solar panels that give about 36v.

    1. Dear sir, I want to run a deep freezer and a washing machine at day time only i mean without batteries, kindly guide me that how many panels of how many watts i need

      1. Dear all,
        I would like to ask for support about Solar system:
        I have the total load of 600 Watts and I have 2 batteries (deep cycle ) with 190 Ah /12 V each .
        I can also get solar PVs of 80 Watts.
        I want to use my load for 5 hrs.
        #what is the number of solar panels I can use
        #What is the size of charge controller may I use
        #what is the size of inverter may I use
        #are these batteries enough to run my load?
        #when installing solar PV on structure, what is the angle to respect (inclination)

        Nice to hear from you

  8. I want to make a( 300A) how many solar cell for that?
    And what is the best way to contact them by parallel or series way?
    Thank you so much

  9. sir i want to make 500 watt ON Line UPS . how can i find design calculation to ratings of inverter , rectifier, transformer, and battery size . please guide about this?

  10. You arrived at the right answer and unit but there were some minor mistakes in units. Ex. 120 watts multiplied by 4 hours. The resulting unit should be watt-hours, and it is no longer power, it is Energy.

  11. Dear, Nice work (Y).
    Need your help. We are panning to installed outdoor 4 digit LED display board , size: 2×1 m, total power consumption by LED board is around 120W,. We want to run LED board 24/7, . please let us know what solar panel will be sufficient for this project. ad please also explain how we should connect LED display board with solar panel.

    1. We are planing to installed a 4 digit LED display board (size 2×1 m), its total power consumption is around 120W, we want to run it 24/7. Please suggest what are the items we require and what should be power of solar panel and how many solar panel are required for this. daily sun outage is around 7 hr. and how we should

      1. You need only one solar panel of 365W, Invertor of atleast 500W, and you also need a battery of 100AH(dry gell) for good backup

  12. Good that you have started the topic, but there are lost of factors you are missing in battery capacity max discharge level of battery, Wp generation of panel, duration of solar irradiation; the problem is the reader get a very bad idea by out of this.

  13. Hi there i have paid R170000 to be off frid totally just to find out im still not of them they tell me i need another 6 solar panels plus a mttp control box which will solve the problem that has cost me R25000 extr so now we standing on R195000 and guarentee me ill be totally off grid no eskom power i alreadu have 30 solar panels 2 inverters and 4 lithium batterus apparantly 1 battery costs R27000 during day system runs dine its in the evening when sun os down the batterys dont carry me through i said theres a shortage of batterys no they say the extra 6 solar panels and mppt controller will solve the problem to carry me through in the fve so in the morning it wont change over to eskom it wil go direct to solar . So im waiting as they are going to install the other 6 todat with controller and then i will see if i no longer am.going to make yse of eskom can somebody assist

  14. sir when u multiplied 120Wx4hour=480Wh. Now its Wh rating. After u divided 480Wh/6hour = 80w. Now its only 80Watts but not 80W per hour [80W/h] as u mentioned in ur text. Kindly review it. secondly for operating 120W DC u must install atleat 150W panel to accommodate losses. only 80W PV will not work to run a 120W load.

  15. Dear sir
    I have installed 8 solar panels of 32 v and have 200 ah 16 bty and have converted wiring to dc all lights and fans of dc runs on 190 to210 dc volt
    I have four inverter voltas 1.5 ton ac and a fridge and washing machine
    And another six solar panels of 12 volts idle how to use them for ac and fridge and washing machine

  16. Sir,
    I need complete guideance for installing Solar system at my residence at Howrah Kolkata West. I am prepared to buy all equipment from you. for 2 K w power approx. Please can you send some person to my residence at assessing the correct amount of power and equipment and approximately total cost. for which l am ready to pay. For further details please contact me on 9163571706 . Regards

  17. How many solar panels required for 2 bedrooms, hall kitchen, with fridge, tv, computer & washing machine. Also give details of inverter and battery backup.

  18. I need solar installation for a 5 roomshouse with 4 security lights, tv and water heating . What’s the requirements.

  19. I love how solar energy turns into one of the cheapest source of new electricity generation capacity in the country. Especially the Philippines, as it is a tropical country. With simpler methods, you can now achieve energy with today’s low-cost panels.

    1. Hi, hi want to connect 2solar panels of 150w each directly to 12v battery 200Ah for running the 3 AC ceiling fans.
      Will it be correct form?
      How much backup it will provide?

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