Modern market of solar modules offerssolar batteries of three basic types : silicone (single-crystal mono - Si and polycrystal poly - Si) and thin film type. Last type is not very popular for electricity production at industrial scales (despite the fact that thin film have some advantages, their productivity is considerable lower compared to silicon-based modules). So choice of solar panels is actually the choice between two most popular technologies of their production: monocristalline or polycrystalline silicone.
It is commonly believed that single-crystal solar panels have number of advantages above polycrystal (multi-crystal) panels, but their cost also differs significantly:
The last fact is, perhaps, most indisputable one: cost of mono-Si modules is really higher, than their poly – Si countertype, made on multi-crystal technology. But it is much more important to know which panels, single-crystal or polycrystal, have better price/productivity ratio. How many square meters of area could be saved, if we replace poly-Si panels in favor of mono-Si. To understand, which abovementioned statements about solar panels are true, and which are simply advertising tricks of equipment producers, design engineers of Rentechno company undertook their own theoretical study of the problem. To reveal relative efficiency of solar panels of different types and different producers (all of them belonged to Tier 1 class), modules of equal power capacity and production class were used.
Research was conducted on the base of photo-electric (solar) station with 10 MW power capacity, built in Kirovohrad oblast. All photo-electric modules were tested under equal conditions: oblique angle of panels to the ground was set to 33 degrees, 2,5 MW Siemens PVS 2520 network inverters were used. Comparison was made among solar panels, made by suppliers from Top-20 in world classification of equipment producers. Research results were confirmed by calculations with the use of special software. Obtained data are generalized in table below:
Explanations: "Performance Ratio PR, %" column specifies work efficiency (ratio of theoretically possible generation of electric power to actually generated amount) of a solar power-station. Because identical inverters were used in research study, so efficiency of a solar power station can be matched with efficiency of certain solar battery type.
Last column, named Variance, % shows differences between polycrystal and single-crystal panels. If value is negative, then a polycrystal panel demonstrated higher efficiency during tests.
As we can see from the table results, unambigiuous statement, that single-crystal modules are considerably more productive and more effective over polycrystal ones, is not quite right. Comparison of different types of solar modules gives different results for different producers. For example, JA Solar shows efficiency index of mono-Si panels 2% higher than at polycrystal. But Trina Solar (one of leading companies on the market) panels comparison gives opposite results: poly-Si panels appear to be 2,6% more productive than single-crystal counteritems. On average productivity and efficiency indexes of polycrystal and single-crystal modules have insignificant differences within 0,1-0,2%. That gives an opportunity to say, that efficiency of single-crystal solar panels is considerably overestimated, possibly in order to justify their higher cost. Relying on obtained data, it is also possible to make certain conclusions about area saving during installation of different types of solar panels.
It is now possible to proceed to the main question of price/quality (productivity) ratio. On the average market price of single-crystal based panels is 15% higher than polycrystal modules. Choice of certain solar panels type always require to compare modules efficiency and their price, with further comparison to panels of similar production class. If price difference does not exceed 2%, then it is better to choose single-crystal panels. Otherwise it is not necessary to overpay and the optimal solution is to purchase polycrystal panels for solar power-station.
Diagram shows comparison of annual amounts of electric power, generated with single-crystal and polycrystal batteries of different producers:
Diagram, named Performance Ratio PR, displays comparison of efficiency, analyzing generation of solar modules within one product line, but of different types (mono-Si and poly-Si) :
All calculations are conducted with specialized licensed software. To get detailed reports on conducted tests or make calculations for your specific type of solar panels (modules), please contact with Rentechno company. One of key advantages of cooperation with Рентехно is that we are not representatives of some single producer or trade mark at Ukrainian market. We pick up equipment due to optimal price/quality correlation, purpose of a photoelectric station, and also customer’s budget.
Actual information about TOP-5 of inverters manufacturing companies is available here.