Top Solar Modules Listing – December 2023

Monthly TaiyangNews Update on Commercially Available High Efficiency Solar Modules
 Cell efficiency matters: For our monthly top module listing we have chosen a benchmark efficiency of 21.5%. The list of 51 commercial products shows that today PERC is not able to support module efficiencies beyond 21.7% – and high efficiency cell architectures are required beyond that level. (Source: TaiyangNews)
Cell efficiency matters: For our monthly top module listing we have chosen a benchmark efficiency of 21.5%. The list of 51 commercial products shows that today PERC is not able to support module efficiencies beyond 21.7% – and high efficiency cell architectures are required beyond that level. (Source: TaiyangNews)
Published on
  • TW Solar introduces powerful HJT module offering 715 W power reaching 23.0% efficiency, while Akcome's Ak iPower HJT module specs have been updated, increasing efficiency by over 0.1 percentage points to 22.37% efficiency with 695 W
  • Runergy and SolarSpace TOPCon module listings have been replaced with new and little higher efficiency modules, now offering 22.5% and 22.45%
  • TaiyangNews has launched an excellence badge scheme recognizing leading manufacturers of top solar modules for 2023

With this December 2023 edition of the TaiyangNews TOP SOLAR MODULES, we have finished exactly 2 years, which makes this our 24th monthly edition. Here, we reiterate that the motivation behind this effort was to create a simple overview for the technically most advanced module products. The key feature of this overview is that we only list commercially available products. As to why efficiency? It is the crucial module parameter that helps increase the energy output, reduces the land and roof area required for PV system installations, decreases costs and, last but not the least, also reduces the carbon footprint of a solar panel. In addition to publishing a monthly update, we have also published 2 reports analyzing the data for the year 2022 and H1-2023. As a further development of that project, TaiyangNews has now started an excellence badge scheme. Those module manufacturers that were featured in the top 10 of the Top Solar Modules list for at least 6 months of a calendar year are highlighted (see company logos of 13 companies below), and qualified to apply for the 2023 badge of excellence (see photo).

Of the 32 module manufacturers currently listed in the TOP SOLAR MODULES list, 13 companies managed to be in the top 10 for at least 6 months of the calendar year 2023.

During the Solar Solutions 2023 trade fair in Duesseldorf, Aiko, the current No. 1 in the ranking, was awarded the TaiyangNews TOP SOLAR MODULES 2023 badge of excellence (photo credit: Aiko)

Changes in December 2023

For our December edition, the list has changed slightly. The product count has increased by one to 55, while the number of companies remains at 32. TW Solar, while already represented in the PERC and TOPCon segments, has created ripples with its HJT product range that boast a high efficiency of 23% and a power output of 715 W. This module is the second product after Huasun's HJT module that has a power rating of over 700 W. There are also 4 companies that have upgraded their product offerings. Following the efficiency order, Astronergy's highest efficient TOPCon solar module comes with 22.65% efficiency, the highest of all TOPCon products listed here. In the same cell technology stream, Runergy and SolarSpace have also added new products with 22.55% and 22.45% efficiency, respectively. Akcome is yet another company that has updated its product offering, but in the HJT technology segment, with a top efficiency of 22.35%. While technically unchanged, LONGi Solar has now adopted a new naming strategy by adding an "X" before the numeric portion of its entire module series; for example, the Hi-MO 6 is now called Hi-MO X6.

These changes, however, have not affected the top layer of the Top Solar Modules listing. As in the previous edition, Aiko Solar, one of the leading Chinese cell manufacturers that has expanded into modules, again holds the top position with a groundbreaking commercial record efficiency of 24%. Aiko's AIKO-A620-MAH72Mw has a power rating of 620 W. Like its predecessor, the new record module product is also from its ABC module series that relies on back contact cell architecture. In May, we included LONGi Solar's Hi-MO6 module with an updated efficiency of 23.2%. As a result, LONGi has made the No. 2 position its own, which it shared with Maxeon before May 2023. Huasun, which has moved to 3rd place from 5th in September – when it released its 715 W module from its Himalaya G12 series, which uses HJT 2.0 technology and is aimed at utility-scale applications – has retained its position.

For details about the different modules, please check the Results & Changes section below, following the Background and Methodology chapters.

Background

Efficiency and output power are the 2 key characteristics of a solar module. While there are several means to improve module power such as employing larger cell sizes or integrating more cells into a module, it's the efficiency that truly speaks about the ability of the solar device to convert sunlight per area into power. That's why this list includes only the highest efficiency solar modules.

TaiyangNews has been covering the efficiency progress of solar modules through its annual reports on Advanced Module Technologies starting from 2017 and its annual conference as of 2020. Our latest Solar Module Innovations Report was published in August 2022 (download report here ) and our most recent annual conference on Solar Module Innovations took place on January 31, 2023 (access the presentations here). However, in the quickly changing solar sector, a lot happens over the course of a year. To keep our readers updated about the efficiency progress more frequently, TaiyangNews started publishing this monthly column on commercial TOP SOLAR MODULES at the beginning of 2022. TaiyangNews has also published 2 reports presenting the analysis of this monthly list – an annual overview analyzing the developments over the course of last year, (see TOP SOLAR MODULES 2022), and an extended analysis to June 2023 that was published and distributed during Intersolar Europe (see  TOP SOLAR MODULES H1-2023).

Methodology

Before going into the details, here is some background on the methodology and selection criteria: Module efficiencies have been improving considerably in recent years, more than 0.5% average per year. In order to make the list rewarding for technically advanced products, we set the minimum efficiency to feature in the list at 21.5%. We have listed only commercially available top modules from each cell technology stream of one module maker. For example, if a company is offering 2 different product streams based on PERC technology that have more than 21.5% efficiency, then only the product with the higher efficiency is considered for this list. But if a module maker is offering, for example, products based on PERC and TOPCon that have efficiencies of 21.5% or above, then both the products are listed here. Efficiency is the only criterion for ranking in the list (whenever available in the specs, we have used 2 digits after the comma for efficiencies, otherwise one). However, as we see more often products with the same efficiency, power determines the order in this case. And when both efficiency and power are the same, we list the manufacturers in alphabetical order.

The list does not distinguish between different module formats; all typical module sizes used in rooftop and ground-mounted solar system applications are included and treated equally as companies increasingly use larger modules also for rooftop applications.

A commercially available module is considered a product for which the complete data sheet is listed on the module producer's website. The efficiency and power data listed here is taken from the data sheet available on the respective company's website. This also means that any new product announcements without final technical data published are not included in the list as their module specs often differ considerably from the products that are finally available for purchase, and some products presented at trade fairs do not even see commercial light at all. Finally, we are only listing modules based on in-house produced cells of a respective module manufacturer, which means modules using externally sourced cells are not featured in the TOP SOLAR MODULES list. If module specs listed on the websites seem to have 'conspicuously' high efficiencies, we ask for certificates from third-party test institutes, among other information, before we include a product in the list.

Results & Changes

Meeting these criteria, according to our research (status: first week of December), a total of 55 products from 32 companies have made it to the current list – one product more compared to the last time, while the number of companies remain the same.

Aiko's ABC module series remains at the top with an efficiency of 24%, surpassing its own previous high of 23.6%. This change happened in the month of June. Aiko's ABC module product is rated with up to 620 W power coming from 144 M10 half cells. Aiko has not specified the exact cell architecture, but it's based on n-type wafers and characterized as ABC, which is also the designation of the module series and stands for All Back Contact. This ABC White Hole Series panels feature a grid-free front design for improved aesthetics and a uniform appearance. Their low temperature coefficient (0.29%/℃) minimizes power loss in hot climates. The module efficiency was certified by TÜV SÜD, and the product is also commercially available. Aiko has also provided a list of projects as proof where the module series has been used in commercial-scale installations.

The Hi-MO6 module from LONGi was updated in May – at 23.2% from 22.8%; it has remained unchanged in the No. 2 position. LONGi's product is based on its proprietary HPBC cell technology, which is essentially a back contact cell architecture. Apart from being top class in efficiency, the new Hi-MO6 module series is powerful too. It reaches up to 600 W in the highest power class. The 144 (6×24) half-cell panel is a single glass (3.2 mm) product with an anodized aluminum alloy frame, measuring 2,278 x 1,134 x 35 mm and a weight of 27.5 kg. The module with up to 23.2% efficiency also features a 25-year power warranty with <1.5% power degradation in the first year and an average of 0.40% from years 2 to 25.

Huasun's HJT module remains at the 3rd place, which is the most prominent change that happened in September. Until August, Huasun was listed with 22.53% efficiency with 700 W power. The Himalaya series module from Huasun is based on the G12 wafer size and a 132 half-cell configuration. The module has an efficiency of 23.02% and a power rating of 715 W, which was the highest among all listed products for a few months – a rank it now has to share with Tongwei; but the release of that product was also the first time that a module surpassed the 700 W benchmark. The module is also bifacial, which, along with its high power attribute, makes the product highly compatible to utility-scale applications. Huasun has been promoting this outstanding product for a few months but has provided production and shipment numbers only now, thus confirming commercial availably that has led to the inclusion of the product in our ranking (See Huasun's Director of Business Development Europe Christian Comes' presentation on Designing HJT Modules For Various Applications here).

A major change comes in the 4th place, with TW Solar entering the list directly with its HJT module. This module is listed for the first time. TW Solar featured TOPCon and shingled panels until last month. The newly listed module is built with 132 cells of the 210 mm format. It is designed with the company's THC products – an n-type HJT cell technology. The highest power rating for this bifacial module is 715 W, and an efficiency of 23.0%. Tongwei has also provided production details and a testing report for this panel. This module shares the 4th rank together with Maxeon's IBC module, called Maxeon 6. This module is built with 66 cells of the 166 mm format, and is designed with a white backsheet and a black frame structure. With 23% efficiency, 445 W power and n-type IBC cell technology, it comes with an outstanding performance warranty period of 40 years.

SPIC, which was ranked 5th previously, has now moved a step down to the 6th place. While the company had been promoting an efficiency of 22.3% till August, it made a remarkable change in September by improving the efficiency of its top product by 0.5% absolute. Its latest Andromeda 3.0 product series comes with a top efficiency of 22.8%. The company has also provided the shipment and production data, indicating the commercial availability of the product. The module features an elegant full black design combined with SPIC's TBC cell technology, which is an IBC concept adopted on TOPCon base cell architecture. The bifacial module, with a bifaciality of 70% and built with 120 half cells, has a power rating of 410 W. SPIC is offering a 30-year power warranty for this product.

The next change can be seen from Astronergy. The company's AstroN5, which was last updated in the September edition to 22.6%, has improved its efficiency again, by 0.05%. This puts it at par with Jinko Solar at the 7th place. The company promotes the product now with 22.65% efficiency that is produced and shipped in commercial quantities. The latest variant of the Astro N5 series, like the previous one, is also a bifacial panel built with 144 half-cut cells of the 182 mm wafer format and unaltered power rating of 585 W.

JinkoSolar shares the 7th rank with Astronergy with its Tiger Neo TOPCon module JKMN-72HL4-V that is offered with a power rating of 585 W. This module has a 132 half-cell configuration and an efficiency of 22.65%.

The best module from Jolywood, the early adopter of TOPCon technology whose products have not undergone any changes technically, stays at 9th. However, its former Niwa Light module was replaced with a bifacial product called Niwa Pro in August, which has the same specifications of 440 W power and 22.53% efficiency.

The next efficiency level of 22.5% is shared by as many as 8 companies ranked 10th. This group has grown by one more company – Runergy. Risen gets the first mention in the group, which is structured according to power first, and if equal, an alphabetical order is applied.

Risen Energy's Hyper-ion module, which was included in June, remains unchanged. This HJT module from Risen has an efficiency of 22.5%, corresponding to a very high rated power of 700 W. The product is built with 132 half cells, cut from the 210 mm original format, and is bifacial. It shares the 10th rank with 7 other products on the list.

Trina Solar's Vertex N series replaced the previous Vertex S+ in the September edition. While both the product groups have the same efficiency, the one featuring Vertex N has a high power of 700 W compared to 450 W for the former. Thus, the company's order among the products ranked 10th (22.5% efficiency) has gone up from the penultimate position to second. The TSM-NEG21C.20 is built with 210 mm wafers and 132 half cut cells. This bifacial module, using a 2 mm glass on both sides, reaches a bifaciality of 80 ± 5%.

DAS Solar's DAS-DH156NA is also listed on the 10th position. This n-type TOPCon solar module remained unchanged with 156 half cells and 630 W power.

JA Solar's TOPCon listing also saw a change in power ratings in the August edition. The JAM72D42 630/LB has a higher power of 630 W compared to the 530 W JAM72D40 580/GB product, but the efficiency has stayed the same at 22.5%, and thus ranked 10th. It is a bifacial double glass module with a bifaciality of 80 ±10% and is built with 144 half cells of the G12 size and 16 busbars. As to the physical characteristics, the module measures 2,465 x 1,134 x 35 mm and weighs 34.6 kg.

Canadian Solar's TopHiKu6 TOPCon model is yet another module that offers 22.5% efficiency. The module entered our list in June 2023, replacing a bifacial product, and has an efficiency that is 0.2% points higher. CS6W-560-580T has 144 half cells based on the 182 mm wafer format. Interestingly, one more product from Canadian Solar also shares the 10th rank. However, this HiHero series, based on HJT, is a smaller module built with 108 G12 wafers in a half-cell configuration, and thus a lower rated power of 440 W.

The new entrant to the 10th place, up from 21st place through a 0.1% absolute efficiency increase, is a module from Runergy. Runergy's TOPCon module, listed with 22.4% efficiency until November, has now improved to 22.5%. The company is another leading Chinese cell vendor that ventured into the module business recently (for background, watch our interview with Runergy CTO Yang Yang). The 2 product streams of Runergy, based on TOPCon and PERC cell technologies, were featured in our review for the first time in July. Runergy's HY-DH144N8 is built with 144 half-cells in the 182 mm wafer format. The bifacial module has a TOPCon cell architecture and a module efficiency of 22.5%.

TW Solar's TOPCon module, which joined the list in April 2023, has remained unchanged since then and is now at the 10th position. The product is designed with a TNC cell type, an anodized aluminum alloy frame and features a linear warranty of 30 years for power output. This product is also built with 144 half-cells of the G12 wafer format and has an efficiency of 22.5% and 580 W power.

DMEGC, that entered our listing in June, has not made any changes to its listed products. The company's TOPCon bifacial module featured here is designed with 144 half cells of the 182 mm wafer format that ultimately reaches an efficiency of 22.45% and a corresponding rated power output of 580 W. This earns it an 18th position, which it shares with products from 4 other companies listed below.

A product series called STAR Pro that was updated in August is representing EGingPV's TOPCon range in the list. The top module of the STAR Pro comes with a module efficiency of 22.45%. This bifacial module, built with 144 half-cells of the 182 mm wafer format, has a rated power of 580 W.

Qn-Solar, a Chinese solar cell and module manufacturer, entered our list in July 2023. Originally a project developer and EPC, the 2014 launched Shanghai-headquartered company also operates its own power plants, and has been strongly expanding into the manufacturing field recently to reach 69 GW cell and 39 GW module capacity in 2023, according to the company's website. It is promoting TOPCon modules with an efficiency of up to 22.45%, thus is one of the 5 products featured at the 18th position. Qn-Solar's listed bifacial TOPCon product has a rated power of 580 W and is built on the 182-wafer format with 144 half-cells. Qn-Solar is also promoting a PERC module that qualifies with an efficiency of 21.57%, which earns it an inclusion in our current listing at the 44th position. That module has an output power of 670 W.

SolarSpace also belongs to the category of leading cell manufacturers venturing into module making. The company, offering both PERC and TOPCon products, entered our rankings in July. This month, its Lumina II based TOPCon module is replaced with a high efficiency variant from 22.02% to 22.45% As a result, its ranking has moved 10 places to 18th, up from the 28th. The 580 W module is built with 144 half-cells based on the 182 mm wafer format and has an efficiency of 22.45%. Lumina I from SolarSpace is a PERC module with 21.57% efficiency and is one among 7 products sharing the 44th rank on the list.

URECO is a manufacturer formed after a merger of the 3 leading cell manufacturers of Taiwan – Neo Solar Power, Gintech and Solartec. The company has products on offer that are based on all 3 mainstream cell technologies – PERC, TOPCon and HJT. While PERC products were already part of our earlier listing, the modules based on the remaining 2 advanced cell technologies were included in our August edition. Named GLORY, the company's TOPCon series is represented through its FBF580B8D model with an efficiency of 22.45%, which means it shares the 18th place with the above mentioned 4 products from DMEGC, EGingPV, Qn-Solar and SolarSpace. The HJT module of the company, with a rated efficiency of 22.44%, misses the spot with a very narrow gap of 0.01%, putting it 3 ranks down to #23. Called GLORY HELLO, the module is built with 120 half-cells using the 210 mm wafer format and has a power rating of 635 W.

As a result of Runergy's product going up the ladder, Suntech's TOPCon module now stays alone at the 24th position with the same efficiency of 22.4%. This bifacial module is built with 182 mm sized 156 half-cells and has a power rating of 625 W. Another product from Suntech featuring since July 2023 has an efficiency of 21.7% and is among the top efficiency products in the PERC category, which is now in the 32nd place.

Akcome, which was 26th until recently with 22.22%, has now moved one step up to 25th place with an increase in efficiency to 22.37%. While the product branding has not changed, including the model name, the power and efficiency have been updated. The Ak ipower HJT module is built with 132 half-cells based on the 210 mm wafer size and reaches a rated power of 695 W. The dual-glass module achieves a bifaciality of up to 90%, resulting in a power generation gain of 7%-30% on the back side. Akcome also promotes a 560 W and 21.68% efficient bifacial PERC module built with 144 half-cells sliced from M10 cells. This PERC product shares the 38th rank with JinkoSolar's Tiger Pro PERC module that has the same efficiency.

Yingli Solar, one of the early adopters of cell architectures based on n-type wafers, finally found its way into our listing last month through its PANDA 3.0 PRO, a TOPCon module product. The cells used in this module are made from the in-house 5 GW cell production capacity for TOPCon, while the company has 20 GW capacity for modules including PERC and TOPCon. The listed module is built with 156 half cells. The bifacial module interconnected with MBB technology has an efficiency of 22.36% and a power output of 625W. This module is at the 26th position, while another module from Yingli ranks 44th in the PERC category.

Part of the vertically integrated GCL Group, which is a global leader in silicon production for the solar industry, GCL Integration (GCL-Si) is offering solar modules and battery storage products as well as full PV project solutions (for details on GCL Group, watch our interview with Group Chairman Gongshan Zhu). In the July edition, we included 2 module products from GCL-Si. The GCL GEMINI, representing the TOPCon range of the company, has an efficiency of 22.3% and a power output of 575 W. The bifacial n-type module is designed with 144 half-cut cells based on the 182 mm wafer format – and shares the 27th rank with REC.

REC's top HJT module offered commercially hasn't seen any change in 2023. The Singapore based manufacturer's Alpha Pure-R series HJT product is available with an unaltered efficiency of up to 22.3% and 430 W module power.

CECEP Solar Technology Zhenjiang is a Chinese cell and module producer founded in 2010 that operates around 4 GW of cell and 8 GW of module capacity, according to its website. CECEP's first-time featuring TOPCon product is a High Efficiency series bifacial solar module made with 144 half-cells based on M10 n-type wafers. The product is rated with an efficiency of 22.1% and a power output of 570 W. This module ranks 29th.

The remaining 26 products listed are below 22%, of which 2 are based on HJT while the bulk are PERC modules.

Jinergy's HJT module, which was updated in September 2023, now ranks 30th. Its efficiency of 21.85% is 0.17 percentage points higher than the previously listed product. Not just efficiency, the JNHM144-475 is a little larger module built with 144 cells, and it also has a higher power rating of 475 W. It is bifacial too, with bifaciality exceeding 85%.

As previously, Meyer Burger is offering its HJT product with the same efficiency of 21.8% and a power rating of 390 W, now listed at the 31st position.

There are several module series with efficiencies slightly exceeding 21.5% available today, as high efficiency cell architectures are not a must to reach that level, but in order to design products today beyond 21.7%, the cell technology is key.

As shown in our TOP SOLAR MODULES H1-2023 overview report, PERC in general was not able to support efficiencies above 21.6% until the end of last year. At the time, modules with efficiencies above 21.6% were generally employing cells based on high-efficiency cell architectures such as IBC, TOPCon or HJT.

Of late, however, we have observed an increase in the number of companies reaching module efficiencies up to 21.7% with PERC. Until November 2022, LONGi and Risen were in this group; Canadian Solar joined the list in January, TW Solar in February, DAS Solar in April, and Suntech joined the list of 21.7% efficient PERC modules in July – and all of them are ranked #32. Following the order of rated power, the third module of Canadian Solar in this list, the HiKu7, is based on the 132 half-cell configuration with 210 mm wafer size and a rated power of 675 W. Risen Energy's TITAN module is built with 132 half-cells of the 210 mm wafer format for a rated power of 675 W. DAS Solar's DAS-DH144PA module is based on a 144 cell and 182 mm wafer format. LONGi's Hi-MO 5m module is built with 144 cells of 182 mm cell size offering 560 W of power. Suntech's Ultra V module has a design of 144 half cells of the 182 mm wafer format and a rated power output of 560 W. TW Solar, which was listing a 21.5% efficiency product until February, has come up with a 21.7% product that reaches a power output of 430 W. Like its predecessor, this product is also based on shingled interconnection technology, stripping cells into 5 and a total of 61 cells are used to build this shingled module.

If rounded, the next 2 would also reach 21.7%, but the companies – Akcome and Jinko – chose not to do so in their spec sheets. JinkoSolar's Tiger Pro is a module with 21.68% efficiency based on a 144-cell configuration, resulting in a rated output of 560 W. Akcome has a bifacial product with the same number of cells, cell format and output of Jinko. Thus, the 2 products now share the 38th rank.

Of the remaining 16 PERC products, 4 reach 21.6% efficiency, one more than the previous month, holding the 39th position. 3 products from this group – from GCL-Si, Talesun and Trina Solar – have the same power rating of 670 W owing to the same cell count of 132 half-cells of the G12 size. JA Solar's DeepBlue 3.0, built with M10 sized 156 half-cells, has a lower power rating of 605 W. While listed lower, it is ranked the same at 40th.

The next 7 products rated with 21.57% efficiency share the 44th rank, of which 3 are from Qn-Solar, SolarSpace and URECO that all entered our list in July, while Jinergy, Seraphim and Yingli are the other 3. ZNShine's PERC module is a new member of this group. The company has a total capacity of 10 GW. The product also leverages bifacial capabilities, the half-cell design, and MBB technology. Similar to the other 6 products listed with 21.7% efficiency, this module also has the same rated power of 670 W. All these products are built with 132 half-cells of the 210 mm wafer format. EgingPV's PERC product is the lone beholder of the 51st rank with an efficiency of 21.56%, but the power rating of 670 W is the same as the products from the group above. The lowest efficiency of 21.5%, which is also the minimum criterion to be included in this list, is represented by 4 products at rank 52. These products are offered by Runergy, Q CELLS, Astronergy and CECEP sharing this position.

Summary

TaiyangNews' latest TOP SOLAR MODULES list as of December 2023 comprises of 55 products from 32 companies. Aiko Solar still leads with its ABC module of 24% efficiency, while LONGi Solar secures the second spot with its Hi-MO 6 module at 23.2%. Huasun's HJT module holds the third position with 23.02% efficiency and 715 W power. All these top 3 ranks remain unchanged over the previous edition.

The major change in the December version can be seen with the 4th place. While until November Maxeon 23% efficienct IBC module was ranked 4th alone, it now has to share this place with TW Solar, which has introduced an HJT module with the same efficiency but with much higher power of 715 W, which means it has caught up with module power leader Huasun. of Astronergy has improved the efficiency for its Astro N5 module by 0.05%, but that had now effect on its ranking – it is still on 7th position. The new TOPCon modules from Runergy and SolarSpace are featured with 22.5% and 22.45%, which earned them much better ranks – #10 and #18, respectively. Akcome's Ak iPower HJT module moved up one spot to position 25, as its efficiency improved to 22.37%.

Report: If you want to learn more about commercial module efficiencies of integrated module producers, please check our TOP SOLAR MODULES H1/2023 report. Here we have looked at the monthly columns for the last 18 months of this ranking – with a focus on H1/2023 – and analyzed the trends and developments for the different cell technologies (PERC; TOPCon, HJT, Back Contact) and listed companies (free download of TOP SOLAR MODULES H1/2023 report here).

PS: If you have spotted a solar module somewhere that meets our criteria and missing in this list, please do send us the website link with the product specs to top-modules@taiyangnews.info.

Disclaimer: TaiyangNews does not guarantee reliability, accuracy or completeness of this TOP SOLAR MODULES Listings content. TaiyangNews does not accept responsibility or liability for any errors in this work.

Related Stories

No stories found.
logo
TaiyangNews - All About Solar Power
taiyangnews.info