How to Choose 36 cell solar panel?

If you're looking to switch to solar, you may wonder if you have enough space to install the panels. This is a valid concern - solar panels are pretty big! Most home solar panels are about 5.5 feet x 3 feet and weigh roughly 40 pounds each.

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Most of the time, you won't see the size of solar panels expressed in feet. Instead, you'll see it's listed as the number of solar cells within a panel, with the most common solar panel sizes being 60-cell and 72-cell.

Let's take a closer look at the difference between these solar panel sizes and how to pick the right one for your home.

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How to measure solar panel size

When you look at a solar panel, you’ll see it’s made up of small squares. Those squares are called solar cells, and they're the part of the panels that turn sunlight into electricity.

You'll see the size of a solar panel described by how many cells it has. 60-cell panels are usually laid out in a 6 by 10 grid and are the most popular option for home solar installations. You’ll typically find that 60-cell solar panels have output ratings between 350 and 400 watts and efficiency ratings between 17% and 19%.

72-cell panels, on the other hand, are usually arranged in a 6-cell by 12-cell grid. Because 72-cell panels hold more cells, they are bigger and can produce more solar power, making them popular for commercial installations. 72-cell panel wattage usually sits around 415 to 450 watts, but they can get into the 460-watt range. Their efficiency ratings are typically between 18% and 21%.

Solar panel dimensions and weight

Many people want to know the physical size of solar panels, not just how many cells the hold. The average 60-cell solar panel is about 65 inches by 39 inches, or 5.4 feet by 3.25 feet, and weighs around 40 to 50 pounds. The actual dimensions will vary from panel to panel, so we’ve listed a few for some of the most popular 60-cell panels on the market:

72-cell panels are larger, about 80 inches by 40 inches and about 1.5 inches tall. This works out to just about 6.5 feet by 3 feet for 72 cell panels, give or take a few inches. 72-cell modules generally weigh around 50 pounds. Here are the dimensions for 72-cell panels offered by top brands:

Pros and cons of 60-cell and 72-cell solar panels

Here’s a brief breakdown of the pros and cons of each panel size.

How big are portable solar panels?

Once solar panels are installed on your roof, you don’t have to think much about their size anymore. 

But, with portable off-grid panels, solar panel size is one of the most important things to consider. Your RV might only have a small amount of roof space, or you might want something you can carry around and set up outside your campsite!

Because portable solar panels are made for travel, they tend to be smaller and have about 40 cells as opposed to 60. 200-watt portable panels are around 5 feet by 2 feet. 

You could also opt for flexible solar panels, which also measure about 5 feet by 2 feet. But flexible panels can bend and are much thinner than crystalline panels, so they’re easier for storage.

The flexible panel sold by Renogy, a popular portable solar brand, has 72 cells, but they’re smaller than the ones used in typical commercial panels. The panel is also substantially lighter, weighing just 10.8 pounds!

Folding solar panel kits are also an option for portable use. Foldable panels can be small enough to fit in your backpack, or large enough to power your RV - there's a wide range of options out there.

Factors that are more important than solar panel size

There are many factors that you should consider before the size of your solar panels, like solar panel efficiency and solar panel warranties. 

Solar panel efficiency

Solar panel efficiency is the percentage of light that strikes the surface of a panel that is converted into usable electricity. Modern solar panels have efficiencies that range from around 17% up to 22.8% in some premium models.

Highly efficient panels take up less space, which will allow you to fit more panels on your roof.

Solar panel warranties

There are two types of warranties that cover solar panels.

The first is the product warranty. This is the period during which you can ask the manufacturer to replace the solar panel should any problem arise. Nowadays, a product warranty of 12 years is standard, but more brands are starting to offer product warranties of 25 years.

The second type of warranty is a performance guarantee. Most mainstream panels have a 25-year production warranty, guaranteeing the panel will produce a certain level of output at every stage of the panel’s life. From the date your panels are installed up until the 25-year mark, the minimum guaranteed output of your panels will gradually decrease.

You can expect an output of close to 100% for year one, gradually down to between 80 and 92 percent for year 25. This loss in output is technically known as solar panel degradation. Some solar panel manufacturers, such as Canadian Solar, even offer a 30-year performance warranty on certain panel models.

Find out if solar panels are worth it for your home

How to find the best solar panel size

The easiest way for homeowners to figure out the best solar panel size for their needs is to work with a dedicated solar installer. Solar installers will size your system based on your energy needs, coupled with your available roof space and the sunlight in your area. They can recommend a system size that can fit on your roof and reduce or eliminate your electric bill. 

Investing In solar power is a smart financial investment towards green energy. The solar panels account for approximately 60% cost of a solar power system and even more important thing is that you have to live with your decision for a long time , say about 25 years and above. So, Choosing the right solar panels is an important step in creating a long-lasting, money-saving solar system. hence, It's very important to ensure that you buy a good quality solar panel. and we can assist you select a reliable solar panel that best suits your requirement.

Criteria you should use while selecting a solar panel

1 . Panel Type

There are two main types of solar panels available in market - Monocrystalline & polycrystalline. Their name is based on the solar cells used for their manufacturing. Monocrystalline is made of pure silicone cell and polycrystalline is made up of multiple flakes of melted silicone.

Monocrystalline panels are more efficient and can generate more power than an equally sized polycrystalline solar panels. They also performs better during low-light and cloudy weather. But as monocrystalline also cost a bit more than a polycrystalline panel, many homeowners who have the available roof space choose a top quality polycrystalline panel over a monocrystalline panel to save money on the solar installation.

2 . Solar Panel Grading A - Grade & B - Grade

There are actually 4 grades of solar panels (A, B, C, D) based on the grades of solar cells used to manufacture them. Choosing anything worse than a B grade solar cell nowadays is quite rare with the onset of the “solar boom” and refined manufacturing processes. The difference between an A and B grade solar panel may not be very noticeable but will make a difference in the long run. So, We simply recommend to always go for an A grade solar panel. An "A grade" solar panel will have no real discoloration, no scratches or dents. It goes through stringent QC using electronic testing equipment to measure quality & efficiencies. As the prices of solar panels are rising, there is no need to sacrifice quality and buy anything lesser than an "A grade" solar panel.

3 . Roof Area, Capacity & Solar Panel Size

When determining the size of solar panel, it’s important to start by thinking about what your goals are.

• Maximize your return on investment?

• Save as much money as possible?

• Reduce your upfront costs?

Once your goal is clear you can determine how many solar panels and which watt you need to achieve that. Solar panels come in three sizes basically: 36 cells, 60-cell and 72-cell. Larger the size of solar panel w.r.t. generation capacity better is the rooftop utilization. Determine your total energy requirements from past power utility bills and calculate the number of solar panels. You can also add your power backup requirements to this considering the size of your battery.

If you have large usable roof area, you can sacrifice some efficiency and buy larger panels (at a lower cost/panel) to get to your targeted power output. But if your usable roof area is limited, or partially shaded, then using fewer smaller high efficiency solar panels may be the best way to generate more power over the long term, ultimately saving you more money.

You can also consider net metering if you are planning for an on-grid solar power system, as you’re considering figuring out your ROI for your solar system. Net metering is how your utility company credits you for producing excess solar energy and feeding back to the grid.

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4 . Compatibility With Battery

Considering battery capacity is important especially when you can’t access the grid, or you just want to store the solar energy into a battery for power backup. Solar panel must be chosen after considering that it must supply enough energy to battery so that it can supply power to the load and also cover-up for the loss of energy in inverters.

Batteries have energy storage ratings mentioned in Amp-hour (Ah) like 150Ah or 200Ah. They also have a nominal voltage of 12 V. So solar panel should be chosen depending on the rating of the battery you are using and the Ah. A 12V solar panel should be paired with a 12V battery and a 24V solar panel should be used with a 24V (2 Nos. of 12V battery connected in series) for efficient functioning.

Now to decide the wattage and number of solar panels you must know the current required for charging the battery. The Required Charging Current for a 150Ah battery would be.

Charging current = 1/10 of batteries Ah

150Ah x (1/10) = 15A

Lets suppose a 100W Monocrystalline Panel has Vmpp = 5A then you will need to use 3 panels of 100W to be connected in parallel to get 15A for charging your 150Ah battery in 10hrs. on other hand if you choose 190 W Mono PERC Solar panel then you will need 2 such panels to charge same 150Ah battery in 10 hrs.

5 . Compatibility With Inverter

Solar panels generate DC (Direct current) and your appliances utilize AC(alternating current). So, you can't connect solar panels to home appliances directly. You will need Inverter to convert the DC to the AC used by household appliances.

Similar to battery, solar panel should also be compatible with the rating of the inverter. Inverters are available in different ratings like 12V, 24V, 48V, etc. So, a 12V solar panel should be used with a 12V inverter and a 24V solar panel should be used with a 24V inverter. On top of that a series connection is required to maintain the same voltage between the battery, inverter and the solar panel

12V solar panel – 12V inverter – 12V battery

24V solar panel – 24V inverter – 12V x 2 battery

For more information, please visit 36 cell solar panel.

For 48 Volt Inverter:

2 Nos of 24V solar Panels in series or 4 Nos of 12V Solar Panels in Series with 4 Nos. of 12 Volt battery connected in series.

24V x 2 solar panel – 48V inverter – 12V x 4 battery

6 . Solar Panel Features & Performance

The amount of electricity a given solar panel can produce is dependent on several factors like power rating/wattage, power tolerance, efficiency and temperature coefficient. Taken together, these factors will guide you how much power your panel will be able to produce.

Tolerance - Solar panels come with a “tolerance” rating which means the panel with either be below, meet or exceed its “nameplate” rating. This is shown on your panels specification sheet and on the panel itself as a -%/+% number.

For example – an ordinary solar guarantees that it produces 375 watts, but in reality it can only put out 370 watts under standard test conditions (STC). This panel may show a -3%/+3% tolerance. It means, it will either produce 3% less than the mentioned wattage due to production issues but also has the ability, under ideal conditions, to produce 3% over the given wattage.

An A-Grade solar panel such asBluebird Solar’s 395W module has a tolerance of 0%/+3% which means the panel has only positive power tolerance i.e. it will only produce more than the rated wattage. This is the tolerance, or efficiency rating, you must to look for.

Durability -

1. Should be built with A-grade solar cells.

2. Heavy-duty silver anodized aluminium frame increases the durability of solar panels.

3. Must be PID, Salt mist & ammonia corrosion resistant.

4. AR coated tempered PV grade glass reduces light reflection

5. Panels are kept in outdoor. Hence, your solar panel junction box must be IP67/68 which make solar panel resistant to water and dust ingression.

7 . Certifications & Warranty

You should also be sure that the panels you install are designed to withstand the conditions in your area. Look for panels that meet the IEC , a reliability standard established by the International Electro-technical Commission (IEC). IEC uses an accelerated outdoor stress test for panels to ensure their durability. In India BIS Certified solar panels like Bluebird Solar stands out as a hallmark of trust.

Solar product warranties are very similar to what you receive whenever you buy consumer goods like iPads, televisions or computers. But with most electronic products, the best you can hope for is about one year of coverage—maybe three years if you buy extended protection. However, PV products warranty work a little differently. solar doesn’t have any moving parts, it is one of the most durable energy generation technologies in the world. Moreover, each component is rigorously tested before shipping to market.

A solar panel has two warranties:

(1) Performance Warranty : Under normal conditions, solar panel output production will degrade to some degree, but it should lose no more than 10-20% over 25 years. Typically, performance drops by one-half to one percent a year.

Typically, A solar panel’s performance warranty will typically guarantee 90% production for 10 years and 80% for 25 years. When panels drop below these figures, the performance warranty will kick in, and you will be able to repair or replace the non-performing solar panel. The company might test your solar panel in their testing facility or get it tested in other third party testing facility and after they are fully satisfied that your solar panel is under performing because of some internal defect in the solar panel they will offer you warranty benefit.

(2) Product warranty : Manufacturing or product warranty protects your product from any manufacturing defects.

• If there is any deterioration in appearance of the product (including any mechanical wear, rust, hot spots, snail trails and other aesthetic defects).

• Damaged frame or glass.

• Loose junction boxes or faulty connectors.

• Bad cells or damaged cell connections

• Defective backsheet.

When Can Company Rule Out Your Warranty?

• If the solar panels are repaired without company's authorization or in any way tampered with.

• If the solar panels are subject to extraordinary salt or chemical exposure.

• If the solar panels are subject to improper installation, application, alteration, unauthorized service, or improper system design which caused constant shading to the Products.

• If the damage to solar panels is subject to power failure or surges, flood, fire, direct or indirect lightning strikes, or other acts of nature.

• If damage is due to accidental breakage, vandalism, explosions, acts of war, or other events outside manufacturers control

• If the solar panels are moved from its original installation location.

• If PV panels are exposed to voltage in excess to the maximum system voltage at the lowest temperature of the place or power surges.

• If the serial number on the solar panel is altered, removed, or made illegible.

What Will Company Provide If You Are Eligible For Warranty?

• Repair the solar module.

• Replace the non-functional solar module with new solar modules whose labelled power wattage’s equal to the Warranted Wattage’s of replaced Products (the Warranted Wattage’s is defined as the contracted power wattage’s of the Products minus the permissible accumulated degradation.).

• Refund the depreciated purchase price paid by the customer for the module as compensation.

The article looked at the important factors to look at before choosing the Solar panels that best suit you.

The important factors to consider are:

• Your goals

• Solar Panel Type

• Solar Panel Grading

• Rooftop area capacity & solar Panel size

• Compatibility with battery & inverter

• Features & performance

• Certifications & warranties

If you are planning to purchase Solar panels, we could assist you in getting the right PV Module that suits your requirements. Contact us for more information.

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