Monocrystalline vs Polycrystalline Panels: Which to Choose in 2026?

The difference between monocrystalline and polycrystalline panels comes from the crystal structure of the silicon from which the solar cell is made. A monocrystalline panel is made from cells cut from a single crystal, while a polycrystalline panel is made from silicon blocks in which many small crystals are fused together. As of October 2026, the panels quoted in new residential and commercial projects in Antalya are in practice from the monocrystalline family; polycrystalline panels turn up in older installations and in stock products.

Monocrystalline vs polycrystalline: the basic structure

A monocrystalline cell is sliced from a single-crystal silicon ingot. Because the crystal structure is regular, electrons meet fewer obstacles and cell efficiency is higher. A polycrystalline cell is cut from blocks formed by casting molten silicon into a mould and cooling it, with many crystal grains inside. Because grain boundaries make electron movement harder, efficiency stays lower at the same technology level.

There is a difference in appearance, too. Monocrystalline panels look dark and uniform in colour; polycrystalline panels have a speckled surface in shades of blue. However, the monocrystalline panels sold today also contain different cell technologies: PERC, TOPCon and other n-type solutions. For this reason "monocrystalline" alone is not an indicator of quality or power.

Efficiency and area: how many square metres for the same power?

Module efficiency shows what percentage of the light falling on the panel is converted into electricity. As efficiency rises, the area needed for the same power falls. Examples from manufacturers' datasheets are as follows:

• TommaTech TT605-144TN10 (n-type TOPCon, monocrystalline): 23.42%
• A large manufacturer's TOPCon bifacial model: 21.68-22.45%
• A PERC bifacial example: up to 21.5%

We do not give a single figure here for the efficiency of polycrystalline panels, because it varies with model and production year, and since there is no common reference among current products, it is more correct to leave the comparison to the product datasheet. In general, the efficiency of polycrystalline modules stays below that of monocrystalline modules of the same period.

To make this concrete, let us do a simple area calculation. The TT605-144TN10, at 2278 × 1134 mm, covers about 2.58 m² and produces 605 Wp; 605 W / 2.58 m² corresponds to an efficiency of about 23.4%. For a 10 kWp system, about 17 of these panels are needed and the total area comes to about 43 m². With a hypothetical module of 16% efficiency, about 62.5 m² of roof area would be needed for the same 10 kWp (calculation, hypothetical example).

The 2026 market: why is it monocrystalline now?

Worldwide solar panel production has shifted largely to monocrystalline cells in recent years. In the product catalogues of large manufacturers today, most new-generation products are monocrystalline PERC, TOPCon and similar technologies. Polycrystalline production has almost dropped out of the mainstream of these catalogues. This is a general observation, not a firm market share figure.

In Turkey too, installed solar capacity has grown rapidly. At the end of June 2026 installed solar capacity reached 27,210 MW, which is 21.6% of the total of 126,113 MW. This rapid growth makes high-efficiency panels, which produce more energy per roof and per plot of land, more valuable; however, we could not find an official figure for the distribution by module type.

If you come across an installer quoting polycrystalline panels, ask these questions: Was the panel manufactured within the last five years? Does the price difference cover the efficiency difference? Are the warranty terms at the same level as current monocrystalline models? Under the 2 April 2026 amendment to the unlicensed generation regulation, main equipment such as the panel, inverter and battery must have been manufactured within the last five years. Old stock polycrystalline panels may not meet this requirement.

Temperature, degradation and warranty comparison

In Antalya the average maximum temperature in July is 34.2 °C. As cell temperature rises, panel power falls. In the datasheet examples, the power temperature coefficient of the current TOPCon panel is −0.30 %/°C and of the PERC example −0.340 %/°C. This difference corresponds to a power loss of about 12% and 13.6% when cell temperature reaches about 65 °C (calculation). You can find the details in our what is a TOPCon panel article.

On degradation, the datasheets differ. The TOPCon example gives 99% in the first year and 0.40% a year thereafter; the PERC example gives less than 2% in the first year and 0.45% a year. In NREL's 2012 literature review, median degradation for modules in the field is 0.5% a year. This study is old and covers older-generation modules. That is, the expected degradation may be higher for older-generation products and lower for new-generation n-type products.

On warranty, the point to note is that the product warranty and the performance warranty are different. For the TommaTech TT605-144TN10, a 15-year product and a 30-year performance warranty are stated. You cannot generalise this information to every brand; if you are buying polycrystalline panels, the warranty document needs to be read separately.

How is the decision made on Antalya roofs?

Where roof area is limited, monocrystalline panels are the clear advantage. On apartment roofs in Kepez and Muratpaşa, water tanks, solar water heaters and stair-head housings reduce the usable area. When area is restricted, getting more watts from every square metre becomes important. We explained how to calculate the installed capacity needed when roof area falls short in our how many kW of solar panels do you need article.

Could a polycrystalline panel have an advantage on wide land? In theory it can be considered if there is no area problem and the unit cost per watt is markedly lower. However, because installation, cabling, rail and labour costs rise with the number of panels, total system cost often does not deliver the expected difference. The real comparison must be made per system, not per panel. So compare quotations with the same installed capacity and the same warranty terms.

Aesthetics is also a factor on villa roofs. In villas in areas such as Döşemealtı, Belek and Manavgat, dark, uniform monocrystalline panels look more in harmony with tiles and roof structure. This is purely a visual preference and does not directly change the amount of production.

Common misconceptions about monocrystalline vs polycrystalline

• "Polycrystalline is more durable." Durability is determined not by crystal structure but by glass, frame, lamination and manufacturing quality. Read mechanical load values from the datasheet; for example, for the TT605-144TN10 a wind load of 2400 Pa and a snow load of 5400 Pa are stated.
• "Monocrystalline loses much more in the heat." The temperature coefficient depends on the cell technology. In new-generation n-type monocrystalline panels the value is lower than in PERC.
• "The efficiency difference is not felt on a roof." If roof area is restricted, the efficiency difference translates directly into installable capacity. As installed capacity rises, annual production rises too; for Antalya city centre the PVGIS figure is 1,656 kWh/kWp.
• "If the price is low, polycrystalline is a bargain." Panel price is only one item of total cost; there are also installation, rail, cable, inverter and labour.

The way to read the monocrystalline vs polycrystalline difference correctly is to seek answers to these questions in the datasheet and a written quotation. You can find the other factors that affect efficiency in our solar panel efficiency article.

Checklist when comparing quotations

1. Are the panel's exact model code and current datasheet included in the quotation?
2. Is the cell technology (PERC, TOPCon, etc.) stated?
3. Are module efficiency and power temperature coefficient written down?
4. Are the product and performance warranties stated separately?
5. Is the manufacturing date within the last five years?
6. Has the roof area needed for the same installed capacity been calculated?

For a capacity and area calculation specific to your roof you can try the solar energy calculation tool, and for a free site survey you can reach the Solar Nexo team through our contact page.

Conclusion

The monocrystalline vs polycrystalline difference runs from crystal structure to efficiency, roof area and warranty. For a new Antalya project in 2026, a monocrystalline panel is in most cases the right and in practice the only sensible choice. Even so, the word "monocrystalline" does not guarantee quality; compare cell technology, efficiency, temperature coefficient, warranty and manufacturing date in writing.

#Technology#Monocrystalline#Polycrystalline#Panel Efficiency#Panel Selection#Roof Area