Why Choose Half-Cell for TOPCon?

Photovoltaic Cells

Solar modules operate with photovoltaic cells as their basic fundamental constituent. The manufacturing sector produces two principal types of photovoltaic cells named full-cell and half-cell.

① Full-Cell

Each full-cell photovoltaic cell contains only one silicon wafer without any partition. The basic manufacturing process keeps the final price affordable.

② Half-Cell

The photovoltaic cell production process consists of slicing one crystalline silicon wafer into two pieces followed by electrical connection of the segments.

Half-Cell Technology

Photovoltaic cell production through Half-cell technology requires the division of normal photovoltaic cells into two parts. The product features 120 or 144 separate half-cells compared to traditional modules with 60 or 72 cells but they preserve the typical module design parameters.

Standard photovoltaic cells experience laser-cutting perpendicular to their main grid lines before both halves receive series connection for welding.

Each half-cell module receives the same encapsulation treatment as standard modules through the combination of tempered glass EVA and backsheet. Each solar cell in normal solar modules connected in a series arrangement produces 0.5-0.6V before power transmission while standard modules typically contain 60 cells. Cell series connection increases the voltage output which leads to a 30-35V operating voltage in a 60-cell module. Standard module connections between half-cells result in half the current output while increasing voltage output to double the original value without affecting resistance levels (as illustrated below).

Standard output consistency for half-cell modules occurs through series-parallel arrangements that join two parallel modules to form effective smaller units.

The opened circuit voltage of half-cells matches the full-cell's voltage value according to the shown diagram. A doubling of half-cell count will lead to each section of the module containing exactly the number of cells present in a traditional full-cell module. The total voltage outcome after part connection remains unchanged because it equals the voltage level of each single section of the cell.

Each half-cell module functions at half the rate of regular cells because they have a reduced size by one half. When implemented with parallel two half modules, the output current closely maintains its equivalent level compared to standard full-cell modules.

Each part in parallel configuration has half the resistance value of an entire full-cell module because the resistance of a half-cell segment equals half the full-cell resistance. The resistance values of two parallel parts reduce to a quarter of the total full-cell resistance because each section holds one half of the total resistance value.

Advantages of Half-Cell Design

i) Lower Packaging Losses

A reduction in internal current and line resistance produces smaller power dissipation through the system. The output power and energy generation improves because power loss reduces directly with current and the reduced current with quartered resistance produces four times less power loss in half-cell modules.

b. Lowering internal losses causes both the module and junction box to experience reduced operating temperatures. Under outdoor exposure half-cell modules maintain a temperature 1.6 degrees Celsius below conventional full-cell modules thus leading to better photovoltaic conversion efficiency.

c. When two halves are not connected in parallel yet they operate as a single solar panel by linking all half-cells then current declines by half while resistance stays the same thus power usage reduces by quarter.

ii) Reduced Shading Tolerance and Hotspot Risk

Every half-cell solar module design demonstrates enhanced performance against shading conditions when compared with typical solar panel modules.

b. Each half-cell module contains double the amount of cell strings at six strings that results in a total six-string panel design. A small shaded portion (for example tree leaves or bird droppings) across the module will cause the failure of only one string. Thanks to the red-highlighted bypass diode design the failure caused by shading will not affect other cell strings which keeps shading impacts at bay.

Each half-cell module contains six independent cell strings which integrate three bypass diodes to have improved shading tolerance throughout the device. A shaded section of any solar module does not affect the functioning of the unshaded portion.

iii) Lower Current Reduces Hotspot Temperature

a. The distribution of internal current is more consistent in half-cell modules which enhances their system performance and lifespan as well as their ability to handle shading conditions.

b. Hotspots develop at specific cells within strings which forces those cells to become operational hotspots in the electrical circuit. Such intensity of heat related to this hotspot area could potentially destroy the module components. The distribution of hotspot heat among double the traditional number of strings within half-cell modules leads to reduced hotspot temperature. The temperature at the hotspot reaches a reduced level of half thus decreasing damage to the module module structure. The life extension of the module results from these temperature-resistant measures which fight against hotspot damage effectively.

iv) Reduced Shading Tolerance Decreases Power Loss

a. Several PV modules get linked in single strings which merge into parallel connections within the photovoltaic array. Current flows sequentially through each module in the series string.

b. A module failure from shading affects every module in its series string when standard module designs are used. The bypass diodes in half-cell module designs prevent power loss from affecting the entire module shielding it from shaded conditions. Instead power loss occurs only within the shaded segment. The built-in diodes direct electrical current to flow through portions of the module that remain unshaded thus blocking current from reaching shaded areas. Shading effects on the module performance become less prominent because of this design.

Since 2018 PowerSourcing has built its reputation as an industry-leading vendor of dependable photovoltaic solutions to supply reliable efficient renewable energy products. We maintain offices and warehouses worldwide to work with significant installers and industry partners offering end-to-end supply chain assistance delivered through specific support networks. PowerSourcing reinforces its commitment to support green energy initiatives in global markets beyond present development stages. We offer ongoing business support to clients who need access to our latest photovoltaic goods together with updated rate data. Contact our team at present.