LONGi vs JA Solar Panels: Which to Choose?

This page compares the two brands directly. For models and prices of each, see LONGi panels and JA Solar panels. If you are also weighing JinkoSolar or Canadian Solar, our Jinko vs LONGi and Canadian Solar vs JA Solar guides cover those pairs.

The two ranges at a glance

The short version: LONGi built its premium panel around back-contact cells, and JA Solar built its range around TOPCon in many formats. Our guide to TOPCon vs HJT vs back-contact panels explains the technologies; we only summarise them here.

Diagram

LONGi vs JA Solar

LONGi

Hi-MO back-contact and TOPCon

JA Solar

DeepBlue N-type

Where LONGi usually comes out ahead

Small and crowded roofs

On a 5 or 10 marla roof with water tanks, a stair tower and parapets, every panel position counts. A Hi-MO X10 puts more watts into each position than a standard-size panel, so the same roof can carry a little more capacity. If you are choosing within LONGi, our Hi-MO X10 vs Hi-MO 7 guide shows the arithmetic.

Partial shade

LONGi says the X10's design loses over 70% less power under partial shade than TOPCon panels. That is a manufacturer claim, but it points to a real difference in how back-contact cells handle shadow. It helps on roofs where a tank, a neighbour's wall or a tree shades part of the array for a few hours. It does not replace good layout; see how shading cuts solar output.

Appearance

The plain front of a back-contact panel looks uniform. Some homeowners with a roof visible from the street prefer that.

Where JA Solar usually comes out ahead

Open roofs and price per watt

On a large flat roof, a school or a factory shed, you are rarely short of space. What matters is a genuine panel at a good price per watt. JA Solar's DeepBlue TOPCon panels are made in very large volumes and are usually competitive here. Compare like for like with solar panel prices per watt.

Elevated bifacial structures

The DeepBlue 4.0 Pro range is bifacial. Raised on an elevated structure over a white or light roof, the rear side collects reflected light. How much that adds depends on height, row spacing and the surface below. See bifacial gain on white roofs and L2, L3 and elevated structures. LONGi's Hi-MO 7 is the comparable bifacial option on its side.

Choice of formats

JA Solar sells several sizes in the same generation, from a 54-cell panel for homes up to large 72-cell panels for commercial arrays. That gives more freedom to fit an awkward roof with whole rows, or to match the structure you already have. For large formats, read 600 to 750 watt panels before choosing, and our industrial and commercial solar page for how we design bigger arrays.

Standard-size panels: Hi-MO 7 vs DeepBlue 4.0

Most home quotes in Punjab are for panels around 580-615 W. Here the comparison is usually LONGi Hi-MO 7 against JA DeepBlue 4.0 or 4.0 Pro. Both are N-type, standard width, and similar in power for the same size. On a normal L2 structure over a dark roof, the difference you will notice is price per watt and availability of the exact version (single-glass or bifacial) that week, not output.

Large-format panels: Hi-MO X10 vs DeepBlue 5.0

At the top of each range, both makers launched panels of up to 670 W at about 24.8% efficiency. They reach that figure in different ways:

• Hi-MO X10 uses back-contact cells with no front busbars, a shade-loss claim and a quoted temperature coefficient of -0.26%/°C.
• DeepBlue 5.0 uses JA's latest TOPCon cell, with a first-year degradation of 1% or less and up to 0.4% per year after that, according to the launch report.

For a shaded or space-limited roof, the X10's design is the more relevant feature. For a large open array, a DeepBlue 5.0 at a lower price per watt may produce the same energy per rupee.

Heat in a Punjab summer

LONGi quotes -0.26%/°C for the X10 and says this is better than TOPCon. TOPCon panels from major makers typically sit a little higher, around -0.29 to -0.30%/°C.

Example arithmetic (illustrative only): if cells reach 65°C on a June afternoon, that is 40 degrees above 25°C. At -0.26%/°C a panel loses about 10.4% of rated power at that moment; at -0.29%/°C, about 11.6%. That gap of about one point is real but small. Poor airflow under the panels can cost more. See solar panels in Punjab summer heat.

Quick decision table

On that last point, see can you mix different solar panels in one system?

LONGi vs JA Solar price comparison

For every brand and wattage, see solar panel price in Pakistan. For a five-brand view, see best solar panels in Pakistan.

What matters more than the brand

• Genuine stock. Both brands are copied and sometimes sold as lower-grade stock. Each runs an online serial check on its own website. Our genuine panel guide and grade A vs grade B panels explain the checks.
• The full model code. "LONGi 620" or "JA 585" is not enough. A JA code such as JAM72D42 tells you the format and series; a LONGi code tells you the Hi-MO generation. The quote should carry the full code.
• Warranty in writing. Each panel carries a manufacturer's warranty per product.
• Design and installation. A well-strung, unshaded and ventilated array of either brand will outperform a premium panel installed badly.

How Solar Works Pakistan chooses between them

We supply both brands and recommend by roof, not by logo. Our in-house engineers survey the roof, check shade through the day, measure the layout and structure, and compare LONGi and JA options on watts per roof, price per watt and inverter fit. The quotation names the exact model, quantity and warranty. Solar Works Pakistan is a Faisalabad-headquartered solar EPC, engineering and trading company, founded in 2021, with 300+ customers and 50+ industrial clients, designing systems from about 6 kW upward. Structures we install carry our 3-year structure warranty. For a first estimate, try the solar calculator.

Get today's price or a free site survey

• WhatsApp or call: 0336 666 4321
• Email: info@solarworks.pk
• Head office: Main Boulevard, Sargodha Rd, Block F FDA City, Faisalabad
• Lahore branch: 2nd Floor, Jeff Heights, Gulberg, Lahore (solar company Lahore)
• Hours: 9:00 AM to 6:00 PM daily

We serve customers throughout Punjab from our Faisalabad head office and Lahore branch. Site surveys are normally free. You can also use our contact page.

Frequently asked questions

Is LONGi or JA Solar better?

Neither is better for every roof. LONGi's Hi-MO X10 suits small or partly shaded roofs; JA Solar's DeepBlue panels often give better value on open roofs, bifacial structures and commercial arrays. Both are major manufacturers.

Which is more efficient, LONGi or JA Solar?

At the top of each range they are level: LONGi quotes about 24.8% for the Hi-MO X10 and JA Solar about 24.8% for the DeepBlue 5.0. In mainstream sizes the two are also close. Check the datasheet of the exact model quoted.

Is LONGi Hi-MO X10 worth paying more for than JA Solar?

It can be if your roof is small or partly shaded, because you get more energy from the space you have. On a large open roof, a JA DeepBlue at a lower price per watt is often the better buy.

Which handles heat better?

LONGi quotes -0.26%/°C for the X10, slightly better than typical TOPCon figures. The difference is about one percentage point of output on a very hot afternoon. Good airflow under the panels matters more.

Can I mix LONGi and JA Solar panels in one system?

Only if each string uses one model and each string has its own inverter input. Never mix different panels in the same string.

Which is better for a factory roof?

Both work well in large formats. On factory sheds the choice usually comes down to price per watt, structure design and how the panel's voltage and current fit the inverter strings.

How do I check that LONGi or JA Solar panels are genuine?

Use each maker's own online serial check, typed in yourself, and match the result to the panel label and your quote. Our genuine panel guide walks through both.

Sources

1. LONGi: Hi-MO X10 introduction (HPBC 2.0 back-contact, 670 W, 24.8% efficiency, shading-loss claim, -0.26%/°C)
2. SolarQuarter: JA Solar unveils DeepBlue 5.0 (Bycium+ 5.0 TOPCon, 640-670 W, 24.8% efficiency, degradation figures)
3. TaiyangNews: JA Solar DeepBlue 4.0 Pro module series (bifacial TOPCon range, formats from 54-cell to 72-cell, power up to 640 W)