Panasonic developed area of more than
practical level of crystalline silicon solar cell unit to achieve a 24.7% of
the world's highest cell conversion efficiency, 0.5 percentage points higher
than the Sun Power Corporation in the United States in 2010 reached 24.2%. The
crystalline silicon solar battery cell has a theoretical efficiency of 29%, but
in the practical level, 25 to 26% has been the limit. Matsushita said,
"The outcome of clear more than 25% of the problems need to be
overcome", plans to further challenge the limits.
Reached 24.7% conversion efficiency of the hetero structure made of the amorphous silicon layer is formed the HIT grid connected inverter is a monocrystalline silicon wafer on both sides. The amorphous silicon layer can reduce the crystal defect of the silicon wafer surface, inhibit recombination losses, and therefore easy to raise the voltage. However, affected by the amorphous silicon layer, a transparent conductive film, and the surface electrode, a part of the sunlight is blocked, it is difficult to increase the current value.
Matsushita by reducing optical losses and carrier recombination loss, the cell conversion efficiency of 24.7% (a). Compared with the Sun Power unit, the short circuit current density was slightly lower (b). Panasonic has been trying to improve the conversion efficiency of the photovoltaic inverter the thickness of only 98μm HIT solar cell unit conversion efficiency up to 23.7% in 2011, increased to 23.9% in 2012. The company's by improving the aspect ratio of the electrodes as well as the inhibition of the light absorption of the transparent conductive film, the short circuit current density by 2012 38.9mA/cm2 successfully raise to 39.5mA/cm2. This made a great contribution to the unit conversion efficiency increased by 0.8 percentage points in one fell swoop.
Sun Power back contact structure, since the surface has no electrodes and therefore easy to increase the current value. The company has developed short-circuit current density of the unit in 2010 40.46mA/cm2. Panasonic this close with current density, and confidently said, "This shows the current value there is room for improvement". Panasonic While the conversion efficiency of the R & D level than Sun Power, but in terms of the amount of product is far from lagging behind the Sun the Power. The the Panasonic production unit conversion efficiency of 21.6%, and the Sun Power has reached 24.2% conversion efficiency in production unit.
According to reports, the new irrigation system unit designed and built by the Solar Energy Research Institute of Yunnan Normal University, started in early December 2012, mentioning the amount of water per day to more than 80 cubic meters, years to mention more than 10 thousand cubic meters of water, effectively solve the water problems of the local people .
In recent years, Yunnan has suffered continuous drought in parts of agricultural irrigation has been greatly affected, and the use of clean solar energy of the system, a significant reduction in the pump station power consumption, reduce electricity costs, reduce the burden on the local people, and the construction is relatively simple, the better to meet the demand for remote mountainous areas in Yunnan drought.