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Solar modules Top-10

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How to choose a solar panel and to understand ratings of photovoltaic modules’ producers?

The world market of sales for solar panels increased more than double in the last few years. And taking into account analycal forecasts, demand on photo-electric solar modules will stably grow in the near future. Combination of increased demand with spead and development of the technologies of solar batteries manufacturing resulted in plenty of producers at the market nowadays, and their number increases constantly. It is quite difficult task for a non-expert, who is not acquainted with realities of this market, to find a way around in such variety of brands and models, to make correct choices here, to buy only quality and reliable solar panels. That’s why Rentechno company, relying on the long-term experience of production and sales of equipment for solar power-stations, offers some advices, how to make correct choice of good solar panels.

Cost of production of the photo-electric modules decreased by several times during last few years. One of reasons for such considerable cost decrease is transfer of production capacities from USA and countries of Europe to the Asian countries, where workers’ wages and other productive expenses are considerably less. It resulted in that nowadays all basic European and American market players manufacture almost all their products in countries of South-Eastern Asia.  China undoubtfully occupies the first place on volumes production of solar panels. Most panels with "made in Europe" label, were actually produced in Asia, only under European requirements.  Similar panels produced in China by large and reliable apeak-integrated producers, are made with very similar quality as those “european” panels. Japan competes China, but authentic japan-made products, similar to American and European, substantially lose in cost competition with producers from Celestial Empire. That’s why Chinese products make the major part of Ukrainian solar panels market.

Solar panels are the most important and most expensive component of any solar power-station (SPS), their correct choice mostly determines efficiency, reliability and longevity of SPS functioning. There are several basic factors, which enable correct choice of quality solar panels. For example, amount of produced panels; it is better to choose solar batteries of that producer, who can provide no less than 500 МW of productive capacity.

But however the main parameter is the class of panels’ quality. There is world-known classification that divides producers of solar modules into three levels : Tier 1 (highest level of quality), Tier 2 (second class) and Tier 3 (lower class). If we compare cost of those panels, then difference between Tier 1 and Tier 3 panels can make up to 20%. We will try to understand, how such considerable payup is formed and is it really reasonable to overpay for some extra quality. Let’s consider in more detailed way, what features each quality class present.


Tier 1 solar batteries

Manufacturing companies on solar batteries market, ranked as Tier 1 level, are top brands with excellent market reputation, and their products are famous for excellent quality.  Only 2% of the world market of photo-electric modules are Tier 1-class products. There are several factors, describing exactly this class of solar modules :


Manufacturing companies, ready to make solar panels of Tier 1 quality class, have their own vertically integrated production facilities.  In other words, a Tier 1 manufacturer does not simply make assembling works of solar panels, using component parts and materials (made by other producers) for this purpose, but also has its own complete cycle of panels production, beginning from growing of silicon sheets/making of photo-electric elements and ending with final assembling works on photo-electric modules. Hard quality control is performed on all production stages.

High degree of automation of all production stages is proper for making processes of Tier 1-class panels, thus human factor influence is reduced to minimum. Solar panelproducers constantly work on perfection of every technological operation, considering operational indefectibility as the basic factor for high quality of manufactured products.

  There is an important marker, what a company, whose products are ranked as Tier 1 quality level, usually works more than 5 years at the global market of solar technologies. Last 5 years solar energy industry experiences real boom, the great number of solar panel producers appeared at the market during this time, presenting thousands of names and brands. Many of these newcomers were not able to survive the hard competition and ceased to exist. So that exactly 5 years is the model term for this hi-tech industry. If a company works 5 years or more, this proves that it was able to organize correctly production processes for solar panels and elements, to get up and running production sales and client support service; that the company is oriented towards long-term business. The longer a company works at the market, the higher probability is that it will accomplish all warranty obligations declared. Tier 1-class manufacturing companies usually make warranty obligations on their products (solar modules and panels) for a term of 10-15 years or even more.

Tier 1-class producers of solar panels invest considerable amounts of money in research and devlopment works (R&D), they have their own patents and constantly implement new innovative approaches and solutions into organization of production and technological processes.

Therefore products of Tier 1 top-brands are actual hi-tech standards with very high reliability and quality assurances. If we compare Tier 1 ratings for last few years, then it is possible to mention that leading positions remain almost unchangeable, they are occupied by same companies every year. Their high-quality products can be strongly recommended for construction of solar stations. Talking about Ukrainian realities, then nowadays most popular solar panels  are produced by JA Solar, Jinko, Trina, Yingli, Hanwha Q Cells and other top brands.   

Q12017 Tier 1 solar panels rating:


Рейтинг Q12017 солнечных панелей Tier 1


Tier 2 solar panels

Tier 2 class producers of solar batteries make some kind of " the golden mean" between the highest Tier 1 class and lower Tier 3 companies. Today Tier 2 solar panels take about 8-9% of global market of solar batteries. Let’s consider key features that are indicative for Tier 2 producers:

  • A Tier 2 class production process of solar panels is automated, although processes automation is not such dominant element, as in Tier 1-class production.
  • Manufacturing companies invest in conducting of research and developments (R&D), but their volumes and quality of research works are considerably less than Tier 1 can provide. However, Tier 2 producers actively implement their own developments for optimization of current products and for launch of production with new types and standards of solar modules.
  • Trade marks of Tier 2 segment in most cases work from 2 to 5 years at the market of equipment for solar power-stations (sunny panels). They have both scientific and productive potential, that could help to rise their class and transgress to Tier 1 category, but they lack for facilities and experience to make the quality jump.


Tier 3 solar panels

It is the most mass segment of photoelectric modules, that has the most lower class of quality. Tier 3-class panels occupy about 90% of all global market of solar batteries. We will mention several factors,  that are distinctive for this class of quality:

  • Tier 3 compaies only make assembling of solar panels, using components and photoelectric modiles made by other companies for this purpose.
  • Productive processes have insufficient level of automation, in a great deal these processes depend on the human factor of manual labour. For this reason solar panels even from one batch can substantially differ in quality of assembling.
  • Companies of Tier 3 level mostly do not engage in conducting of some research activity, using borrowed (in many cases illegally) technologies and developments.
  • Parameters, declared by a Tier 3-class producer in supporting documentation, does not always correspond to real production specifications.
  • Modern market is oversaturated by solar panels of this class.
  • Puchasing a solar panel of Tier 3 class is a kind of lottery, in fact in most cases such acquisition can be compared to well-known “to buy a pig in a poke”. It is possible to purchase solar batteries of good quality, sometimes medium quality can happen, but in most cases it will be not very reliable and productive solar panel.


Price and quality of solar panels: how to compare?

To make right choice with preferred quality of solar panels, it is necessary to specify several parameters before making a purchase. It is not critical, which type of solar panels you will choose: polycrystal or single-crystal. Not so much technology of a panel-making itself is important, but the price per 1 W of its power capacity.  Associated terms, on which you can purchase one or another model of solar battery, are no less important.  Specifications that are necessary to check before you buy a solar panel:

  1. Warranty. More precisely speaking, when purchasing a solar panel, a customer gets two types of warranty: warranty of producer and warranty of elaboration. Nowadays almost all models of solar batteries have warranty of elaboration on photo-electric modules during 25 years. During this specified time productivity of a solar panel will make at least 80% from initial parameters, in other words, generation decline will make 20% or less for 25 years of panel exploitation. It is some kind of industry standard, but future effectiveness of a panel in, for example, 10-year term is much more important.

    Tier 1-class producers of solar panels guarantee that during first year of solar panels exploitation generation losses will be no more than 0,8%, so after 10 years of exploitation power capacity of a panel will decrease no more than 8-10%. Equipment producers of Tier 3 level do not make warranty for proportional decline of generation power, in real terms it can result in that during first or second year of exploitation power can at once fall down to 10%. So time of recoupment of such station will sharply increase for a year or two. If we examine this question from multipurpose perspective, then savings on acquisition of equipment will lead to substantial generation losses in future, and monetary equivalents of these losses will be much more than "saved" purchase costs. Other important factor is warranty given directly by a producer. Foremost, solar panels must be imported in a country legally, with an official representative (the optimal choice) or with a dealer, who presents a manufacturing company.

    A retailer company provides warranty on solar panels only for 1 year, further responsibility falls on a producer company. If you will buy solar batteries of a Tier 1-class brand, whose manufactiring company already works more than 5 years at the market, then it is possible to be sure that warranty obligations will be properly fulfilled during 10 years. And warranty obligations of a company from Tier 3 segment can be considered as quite "conditional", in fact majority of them are fly-by-nighter companies, that develop their activity very quickly, but also disappear in a quite rapid manner. Therefore it is not very wise choice to rely on that they will fulfill the promised warranty obligations to the full extent.


  2. Permissible error of nominal power. This parameter shows, how much real power value can deviate from passport data declared by a producer. For example, power of a solar panel mentioned by a producer is 250 W, and possible power deviation lies within +/- 5% limits. In real conditions it means that actual power of a panel varies within 237,5 - 262,5 W limits. Panels of Tier 1 quality, as real experience shows, have minimum deviation from values in engineering certificates, and this error is always directed to client-positive side. A Tier 1 panel with 250 W nominal power will make not less than 250 W of actual output power. When buing solar panels, you must always require the certificate of testing.


  3. Eefficiency factor of photocells is a parameter that indicates, what amount of solar energy getting on a panel will further transformed into electric current. If we compare polycrystal and single-crystal solar panels, then EF difference , as a general rule, is not very large. Much more important is power capacity costs per 1 W, both types of panels are approximately equal by this parameter, although cost of single-crystal panels is a bit higher. For this very reason EF a panel is not so important, a value higher than 14% is quite acceptable result, although solar panels of Tier 1 class can have efficiency factor up to 19-20,5%. EF value has significant importance, when area for solar panels placing is limited, for example, as most widespread case, for a roof-based power-station. In this case due to the choice of panels with high EF it is possible to decrease area size, required for installation.


  4. Temperature coefficient (also called thermal factor) is another important operational parameter of a solar battery. It's all about some pecularities of photocells functioning, they need much sunlight, but  can't stand high temperatures. When heat falls and solar panels strongly overheated, reduction of produced electric power begins, with considerable enough decrease of generation power. Temperature coefficient specifies, how much generated power will fall down after temperature increases by 1 degree. For modules of good quality thermal factor is -0,4% per 1°C, such values are normative for Tier 1 and Tier 2 class panels. Tier 3 class solar batteries can have temperature coefficient about -0,5% per 1°C. It is necessary to take into account, that testing of these parameters is performed at 25°C, and during summer time own temperature of a solar battery can rise up to 60-70°C. Thus, when temperature of a panel increases by 20 °C, power losses will make about 10%. If a station operates on a green tariff, such power decline will convert into considerable losses of sale volumes of electric power.

Taking advantage of our advices, you will be able to choose by yourself quality solar panels that will provide effective and stable work of solar power-stations. If you have any doubts or you want to have 100-percent quality assurance, then make your request to verified experts in the domain of solar energy, contact with Rentechno managers.


Appendixes. Former ratings of photo-electric modules producers


Рейтинг Tier 1 производителей солнечных модулей


Bloomberg New Energy Finance (BNEF) is frequently requested by clients for a list of 'major' or 'bankable' suppliers - in common industry parlance, tier 1 suppliers - for use in manufacturing forecasts, preliminary competitor analysis, and other internal comparisons. It is very common for industry players to refer to 'tier 1' players, but these terms are seldom defined or described, which is unhelpful for firms outside the solar industry trying to get a basic overview.

BNEF strongly recommend that module purchasers and banks do not use this list as a measure of quality, but instead consult a technical due diligence firm such as Edif ERA (formerly OST Energy), Sgurr Energy, DNV GL, Black & Veatch, TUV, E3, STS Certified, Clean Energy Associates, Solarbuyer, Enertis or Leidos Engineering. These would usually consider what factory the module comes from, as well as the brand, and give an informed opinion on whether the modules will perform as expected.

'Bankability' - whether projects using the solar products are likely to be offered non-recourse debt financing by banks - is the key criterion for tiering. Banks, and their technical due diligence providers, are extremely unwilling to disclose their whitelists of acceptable products. Bloomberg New Energy Finance therefore bases its criteria in what deals have been closed in the past, as tracked by our database -17,000 photovoltaic financings worldwide as of February 2017.

BNEF only tiers manufacturers which actually own production facilities and sell under their own brands. Companies which outsource production under brand names are not tiered. BNEF does not publish a tier 2 or 3 list.

Tier 1 module manufacturers are those which have provided own-brand, own-manufacture products to six different projects, which have been financed non-recourse by six different (non-development) banks, in the past two years. These 1.5MW+ deals must be tracked by our database, ie the project location (sufficiently to identify the project uniquely), capacity, developer, bank and module maker must be in the public domain. One exception is manufacturers which have filed for bankruptcy or a form of insolvency protection, or experienced a major default on bond payments; these are removed from the tier 1 list until further notice.

Construction of industrial solar power plants
Equipment for solar power plants
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