Half-Cell Solar Panels
The solar industry is constantly being disrupted by innovations in solar panel technologies as manufacturers push back the envelope on efficiency and performance of their panels. Like bifacial panels, half-cell, half-size or half-cut solar modules are one of the new and innovative trends in the solar industry that is fast becoming the mainstream. It is estimated that in 2028, conventional full-cell modules (60/72 cells) will have its market share drop to about 35%. The International Technology Roadmap of Photovoltaic (ITRPV) predicts that the market share of half-cell panels will increase from 5% in 2018 to about 40% in 2028.
Traditional full-cell panels are made with 60/72 cells on the entire panel. In a half-cell or half-cut module, the number of cells on the entire panel is doubled into 120 or 144 cells per panel. The panel is however the same size as a full-cell panel but with double the number of cells. The goal of the new technology is to lower the resistance of the panel and increase the efficiency of the panel without necessarily increasing its size.
Since each cell is half size, the cell produces half the current at the same voltage, which means reducing cell shading, losses and increasing efficiency. The lower current also translates to lower cell temperatures which in turn reduces the potential formation and severity of hot spots due to localised shading, dirt or cell damage. In addition, the shorter wire distance to the centre of the panel from the top and bottom further boosts efficiency and can increase power output of a similar sized panel by up to 20W.
Manufacturers of high-powered panels, that is panels that are rated from beyond the 360W that is the optimum for most panels, to panels with power ratings up to 600W, now exclusively depend on half-cut technology. Until at least 2019, the highest rated panels were 360W. Many manufacturers are moving over to half-cut cells especially in their offering of high-power panels.
REC Solar is a half-cell technology pioneer. It first introduced the design in 2014. Ever since, REC has pushed the boundaries with half-cell designs in polycrystalline modules. REC’s half-cell PERC polycrystalline modules have reached 300W, and can compete with full-cell modules in the more efficient monocrystalline class. It has been so impressed by the advantages of half-cells that it is transitioning all its manufacturing lines to the new technology.
Trina Solar now offers an extra-large 210mm square cells in a 1/3-cut cells. LG, Q-cells, Canadian Solar, LONGi Solar, JA Solar, Risen, Phono, Yingli, Panasonic, Suntech and most other manufacturers now offer half-cut cells. JinkoSolar, Risen Energy, SunPower and JA Solar now all offer half-cut high-powered panels with capacities above 500W.
Why Consider Half-Cut Cells?
The most important benefit of half-cut cells is that high-powered panels (that is panels from 450W and above) can now be installed without any concerns for space. This makes them a great option for large-scale installations.
Half-cut panels are more tolerant of shading on any part of the cell. Shading causes a cell’s voltage to drop to its half value. In a half-cut cell, during partial shading, because the cells are connected to act as individual cells, the voltage is maintained and current loss is reduced by 50%, meaning better performance regardless of shading.
Half-cut cells perform excellently in low light situations. This is due to the increased number of cells that receives more sunlight.
Half-cut cell technology is more durable for long-life performance. Most manufacturers offer up to 25 years warranty on their half-cells panel offerings.
Half-cell technology is less susceptible to micro-cracking over longs periods of time due to the smaller size of the solar cells. The mechanical stress on the entire panel is lessened which reduces the opportunity for micro-cracks to develop.
Half-cells performs better in high-heat conditions
Half-cell modules are less susceptible to panel malfunctions.
Half-cell modules come with a split junction box that reduces cell heating and eliminates the possibility of hot spots, a major cause of panel failure.
By delivering more power per square meter, fewer panels are required to generate the same output. This means quicker installation times and fewer components such as clamps and racks—all of which reduces the overall costs. It also means lesser space.