Paving Module is coming
The so-called Paving technology refers to: on the basis of the traditional module manufacturing process, by changing the stringer, the triangle ribbon is used and the cell spacing is greatly reduced. As a result, the packing density of cells is comparable to the shingled solar module. In addition, the paving technology has the advantages of higher yield and no problem from patent limit, compared with the shingled module. With the technology, the efficiency of the module out of the perc cells of 22.1% efficiency can break through 20.2%, which is higher than shingled module. Further more the CTM of paving module even break through 100%.
（Comparison of 5BB half-cut paving module and normal module）
Judgement of a module manufacturing technology
How to judge whether a module manufacturing is better is dependent on two points. One is efficiency of the manufactured module. The other one is cost of the manufacturing. How to judge whether a component packaging technology is excellent Firstly, for the judgment the efficiency calculation of a module should be introduced.
Therefore, with the fixed cells and module size, the bigger value Area ratio has, the higher efficiency the module has.
CTM is an acronym of Cell To Module, which is the ratio of the efficiency of used cells and the manufactured module. For example, the power of 60 pieces of cells before packaged into a module is 335 W. The power of the manufactured module is 325 W. Then CTM=325÷335×100%＝97%.
Since the transmittance of photovoltaic glass is less than 100%, the EVA film and the ribbon will also block or dissipate the light, CTM value normally is always <100%. We call the lost part "packaging loss".
In the term of efficiency of module, the core points of judgement of manufacturing technology are Area Ratio and CTM
To area ratio, Paving module uses two types of ribbon to greatly reduce the gap between cells in a module. It reaches the maximum limit of Area ratio, providing an important geometrical factor for the module to reach a higher efficiency.
1、In paving module, the half-cut cells are used (more gaps in the traditional module), taking full advantage of paving technology. The test efficiency of cell is tested according to the whole size. The half-cut cell has a resistance reduced by half. According to the formula P=IR²，the power loss becomes only a quarter of the original. This part increases the total power of the 60-cell module by 5~6W, which increases the CTM by 2%.
2、 The power loss by the covering area of busbars on a cell is recovered by the triangular ribbon technology. When the power of a cell is tested, the power loss caused by the busbars is ignored by default. When paving module is tested, the light that is blocked by busbars is reflected by triangle ribbon to effective place on the cell.So triangle ribbon technology retrieves the power loss caused by busbars to further increase the CTM value.
Paving module VS Shingled module
Paving module and Shingled module both are the module with the high density of cells layout. Both are the potential mainstream module in the future market.
Here a comparison was made between paving module and shingled module.
(This comparison is based on the cells with same efficiency of 22%)
From the comparison, it is found that the paving technique using a 22% efficient battery can succeed to manufacture a module with efficiency of 20.07%, while the shingled module efficiency based on the cells of 22% efficiency has an efficiency of only 19.6%. The lower utilization of the area of cells in shingled module causes a lower CTM that causes the module efficiency lower than the paving module, although the shingled module has higher area ratio of cell. 95% CTM means when 100 pieces of cells are used, only 95 pieces play a role to generate power, and 5 pieces are similar to waste.
According to the result of research and test, for the high requirement of high efficiency of module in market and saving of the resource, as well as a right development of module production, SUNRISE plans to produce a new series of product with paving technology, which has higher efficiency and higher solar utilization.