Most Efficient Solar Panels 2025

TO Under Stand Most Efficient Solar Panels 2020 we must understand of Solar panel efficiency is a measure of the amount of solar energy (irradiation) which falls on a panel surface and is converted into electricity. Due to many recent advances in solar cell technology, the average panel conversion efficiency has increased from 15% to 20%. This large jump in efficiency resulted in the average power of a standard size solar panel to increase from 400w to 700w

As explained below, panel efficiency is determined by two main factors; the photovoltaic (PV) cell efficiency, based on the cell design and silicon type, and the total panel efficiency, based on the cell layout, configuration and panel size.

Cell Efficiency

The cell efficiency is determined by the cell structure and base silicon material used which generally either P-type or N-type. Cell efficiency is calculated by what is known as the fill factor (FF) which is the maximum conversion efficiency of a PV cell at the optimum voltage and current.

The cell design plays a significant role in panel efficiency. Key characteristics include silicon type, wafer size, number of busbars and finger layout. The higher-cost IBC cells are currently the most efficient (20-22%), due to the high purity N-type silicon cell base and no losses from busbar/finger shading. However, recent mono PERC cells and the latest heterojunction (HJT) cells have achieved efficiency levels well above 20%.Left closeup of a P-type mono 5 busbar cell from a Trina Honey M plus 310W panel . Right: closeup of a more efficient N-type 12 multi busbar cell from a LG Neon 2 335W panel. 

Panel Efficiency

Total Panel efficiency is measured under standard test conditions (STC), based on a cell temperature of 25°C, solar irradiance of 1000W/m2 and Air Mass of 1.5. The efficiency value is calculated by the output power rating divided by the total panel area. Efficiency can be further influenced by several factors including, cell efficiency, the distance between the cells, and the interconnection of the cells.

Surprisingly, even the colour of the panel protective backsheet can affect efficiency. A black backsheet might look more aesthetically pleasing, but it absorbs more heat and increases cell temperature, which in turn slightly reduces total conversion efficiency.

Top 5 Most Efficient Solar Panel Manufacturers

Here are the top 5 most efficient solar panel manufacturers available in 2019. In general the most efficient panels use premium grade N-type IBC silicon cells manufactured by SunPower and LG, however these panels also come at a premium price. Besides REC which also use N-type silicon cells, most other manufacturers use the lower cost P-type monocrystalline PERC cells in either a standard 60 cell or half-cut 120 cell format.

1. Canadian
2. LONGi
3. Trina
4. Jinko
5. JA

NOTE:

Note the efficiency value listed on the panel specification sheet as quoted by the panel manufacturer should be the solar panel efficiency, not the cell efficiency which will be higher.

Why Efficiency Matters

The term efficiency is thrown around a lot but a slightly more efficient panel doesn’t always equate to a better quality panel. Many people consider efficiency to be the most important criteria when selecting a solar panel but what matters most is the manufacturing quality which is related to real world performance, reliability, manufacturers service, and warranty conditions. Read more about selecting the best quality solar panels here.

Solar panel efficiency does generally give a good indication of longer term performance especially as many high efficiency panels use higher grade silicon cells with improved temperature coefficient, performance and lower degradation over time. Some manufacturers such as LG and SunPower even offer warranties with 88% or more retained power output after 25 years of use.

Area Vs Efficiency

Efficiency does make a big difference in the amount of roof area required. Higher efficiency panels generate more energy per square meter and thus require less overall area. This is perfect when roof space is limited and can also allow larger capacity systems to be fitted to any roof. For example 12 x high efficiency 360W solar panels such as those from LG or SunPower with a 21.2% conversion efficiency will provide up to 1100W (1.1kW) more total solar capacity than the same number and size 270W panels with a lower 16.5% efficiency.

• 12 x 270W panels at 16.5% efficiency = 3,200 W

• 12 x 360W panels at 21.2% efficiency = 4,300 W

Real World Efficiency

In real world use the panel operating efficiency is dependent on a number of external factors listed below which can add up to greatly reduce both panel and overall system performance:

Factor which effect solar panel efficiency and performance

• Cell temperature

• Shading

• Panel orientation

• Location (latitude)

• Time of year

• Dust and dirt

The Power Temperature Coefficient

The power output of a solar panel rated in Watts (W) is performed at standard test conditions (STC) and measured at a cell temperature of 25°C. However in real world use cell temperature generally rises well above 25°C depending on the ambient air temperature, time of day and amount of solar irradiance (solar energy – W/m2).

Generally the cell temperature is 25-35°C higher than ambient air temperature which equates to approximately 8-14% reduction in total power output depending on the type of solar cell and its temperature coefficient.

The rising cell temperature reduces power output by a specific amount for every degree above 25°C. This is known as the power temperature coefficient which is measured in % / °C. Monocrystalline cells have an average temperature coefficient (or loss) of -0.38% /°C while polycrystalline cells are slightly higher at -0.41% /°C. Monocrystalline IBC cells have a much better (lower) temperature coefficient of around -0.30% /°C while by far the best performing cells at high temperatures are the HJC cells which are as low as -0.26% /°C.Power output vs Temperature chart shows reduced efficiency at higher cell temperatures – Image credit LG.

Temperature coefficient comparison

Power temperature coefficient is measured in % per °C – Lower is more efficient

• Polycrystalline cells – 0.4 to 0.43 % /°C

• nocrystalline cells – 0.37 to 0.40 % /°C

• Monocrystalline IBC cells – 0.29 to 0.31 % /°C

• Monocrystalline HJC cells – 0.26 to 0.27 % /°C

Generally cell temperature is 25-35°C higher than the ambient air temperature which equates to approximately 8-14% reduction in power output. Note cell temperature can raise to 80°C or even higher when mounted on a dark coloured rooftop during very hot, windless days.

Efficiency of different solar PV cell types

• Polycrystalline – 15 to 18%

• Monocrystalline – 16.5 to 19%

• Polycrystalline PERC – 17 to 19.5%

• Monocrystalline PERC – 17.5 to 20

• %

• Monocrystallin

• e N-type – 19.5 to 20.5%

• Monocrystalline N-type HJC – 19 to 21.7%

• Monocrystalline N-type IBC – 20 to 22.6%

• Cost Vs Efficiency