JINKO MAXIM INTEGRATED SOLAR PANELS – A LOOK AT HOW THEY WORK
You can see the Jinko Solar Maxim Integrated Solar Panels we offer for sale here:
- Jinko 305W Cheetah Monocrystalline PERC MAXIM Cell Optimised Solar Panel
- Jinko 315W Cheetah Monocrystalline PERC MAXIM Cell Optimised Solar Panel
Jinko MX cell string level optimised solar panels for systems that need optimisation, but not module level monitoring. Maxim has developed a single-chip integrated circuit (IC) that replaces the traditional bypass diode providing better module reliability and the function of a DC Optimiser on each cell string within the module. The Jinko MX with embedded Maxim optimisers, combined with Solis, Growatt or HUAWEI o ers an exceedingly cost competitive, and from an optimisation point of view, superior solution for maximum energy yield in all situations.
Conventional solar systems are limited in performance by the series connectivity of solar panels, forcing the string current to equal that of the least illuminated or weakest cells. The Maxim solar cell optimiser works by boosting the current of the weak cells to match those of the stronger, eliminating the corresponding performance penalty of the conventional system. The solar cell optimiser’s MPPT function works alongside the inverter MPPT (with the inverter acting as the master in a master/slave scenario), to ensure that the system output is optimal under any environmental conditions. The Jinko MX modules include three Maxim solar cell optimisers, which replace the three diodes found in a conventional module junction box.
Independent data collected by the US National Renewable Energy Lab (NREL) shows modules equipped with Maxim’s cell-string optimisers outperform standard modules by more than 40% in certain shading conditions compared to conventional non-optimised modules. This is significantly better than even module level optimised solutions.
The benefits of module level optimisation solutions from manufacturers like SolarEdge, Tigo and Enphase are now well known and these solutions are universally used for systems with even modest amounts of shading as their bene ts over the economic lifetime of the system outweigh their initial higher capital cost. The Jinko MX with cell string level optimisation has 3 – 6 times the number of individually managed regions compared to the existing solutions and so offers significantly higher improvements in yield.
There are many advantages of using the Jinko MX – Maxim optimised modules compared to standard module, or individual module level optimisers like SolarEdge or Tigo.
The key advantage of the Maxim modules is that each module cell string is optimised so that a partially shaded module will be less impacted than with a module level optimiser, e.g. SolarEdge or Tigo.
This is especially important with multiple rows of modules, e.g. a at roof mounting system. With conventional modules and a string inverter you can restrict the output from the entire array and even with module level optimisers like the SolarEdge or Tigo an entire row of modules, but with Maxim you typically only restrict one sixth of each module’s energy. This enables a greater yield and/or a greater energy density.
Another other key benefit of the use of the new Maxim II chip in the Jinko MX modules which have a limited Voc is that it enables strings of about 15% longer to be designed than with similar rated conventional modules. When using Jinko MX modules the Voc is limited to a maximum of 35.0V for 60 cell modules, compared to typically 39V for 60 cell modules, which increase with lowering temperatures. This can significantly reduce the BOS costs and enable larger arrays to be designed with specific inverters.
Only one string length is possible per MPPT of an inverter with conventional solar panels, so having individually optimised modules means greater design flexibility. E.g. with the Jinko MX solar panels a design can have different string lengths into the same inverter MPPT depending on the roof requirements, e.g. some 20 panels, others 21 panels. With non-optimised modules all strings into one MPPT must be the same length. Due to the maximum input current restrictions of some inverters this string length mismatch may not be possible or be limited and it is not recommended to have string lengths vary by more than 20% in all cases.
Making installations possible on multi-facetted roofs with different pitch angles. Solar Panels mounted on an east facing roof will produce much lower current than those mounted on the west roof face. An array of standard solar panels into a single MPPT would output power based on the lower current value, whereas optimised modules could use both current values to their maximum and therefore fully utilise the modules with higher current. Designs with aneast-west orientation can generate 3% – 5% extra yield with optimised cell strings.
Solar PV modules of the same rating from the same production line do not possess identical current–voltage characteristics, this is called module mismatch. A series circuit works at the lowest current in the string, so with standard modules the string is limited in current to the worst performing modules. With optimised cell strings each cell strings can perform to its maximum irrespective of manufacturing differences in other strings.
A shaded Solar Panel produces significantly lower current, and the current of the whole string will drop down to the value of the affected module. With conventional solar panels, the entire array current can drop if even only a single module is shaded but with optimised cell strings each cell string will perform to its maximum depending on the irradiance on it (just 50% shading on one cell can activate a bypass diode).
Solar Panels degrade at different rates over time and the output will always be limited by the poorest performing module in a string. The impact of this is di cult to predict, and impossible to measure on day one, but with optimised cell strings each cell string will always perform to its maximum, irrespective of the degradation of any other module.
Soiling can drastically a ect the performance of individual solar panels and more so in low rainfall areas. On average there is a daily e ciency reduction of 0.2% in days without rainfall in dry weather. Annual losses caused by this trend due to soiling ranges from 1.5% to 6.2% depending on the location of the Solar PV plant. The Jinko MX performs especially well with soiled modules compared to conventional modules due to its cell string level MPPT.
Solar Panels produce less energy the hotter they operate at, typically they reduce in output
by about 4% for every 10 degrees increase in temperature. Modules on di erent sections
of roof, and even di erent regions within a module, will reach di erent temperatures due to the amount of ventilation and exposure to even light winds. With optimised cell strings each cell string will perform to its maximum based on the temperature of the cells in that string.
Because the Maxim module does not utilize diodes to manage solar power production, a cell- string will not be bypassed even if fully shaded. (The diffused light will still generate some energy.) And, because all available energy is being harvested, a shaded cell is not in reverse bias, thus eliminating the cause of hot spots and removing a common cause of long-term cell stress. Should environmental conditions still result in a cracked or otherwise degraded cell,this cell will only a ect the performance of its local cell-string, without further a ecting the module or array.
The Jinko MX Solar Panels are installed exactly like standard panels with no extra optimisation hardware or cabling needed so you get all the advantages of optimised modules with none of the additional installation time and costs of a SolarEdge or Tigo. No specialised training is needed over and above that for installing standard modules. An important element of initial Solar PV plant cost is related to installation time. Traditional optimiser systems increase hardware, installation steps and system con guration requirements, thus raising costs—substantially so in larger systems. By incorporating modules enabled with solar cell optimisers, a system designer can maximize harvest without raising installation costs.
A typical conventional Solar PV system will be limited in size to avoid object and row-to-row shading. But PV modules enabled by Maxim will continue to generate maximum energy from shaded cell strings, enabling both a higher density and a larger system to be installed in the same roof space.
With many commercial roof-top applications, especially in European countries, the requirement is to maximise the total energy production from the available roof space.
The ground coverage ratio (GCR) is the ratio of module area to total area and is typically limited to 55 – 60% with conventional modules. Using Maxim modules this can be increased to 70 – 75% enabling 10 – 20% more energy to be cost- effectively generated from the same roof space.
The cost advantages are less with larger systems using the SolarEdge 17, 27.6 or 82.4kW inverters or Tigo with dual optimisers, but the shading, soling and mismatch advantages are larger. Compared to a SolarEdge or Tigo dual optimiser solution you get 6 times the number of individual MPPT regions with the Maxim solution.
Source: Segen
