Hybrid Monocrystalline and Multicrystalline Solar Cells

Suntech Power developed an efficient hybrid solar cell than can reduce the cost of solar power by 10% to 20%. As I mention sometimes in articles, remember not to confuse percentage with percentage points. 20% cheaper is 20% of the cost subtracted from the current cost.

Suntech is a Chinese company and these cells are 70% monocrystalline silicon and multicrystalline silicon is the other semiconductor. The new hybrid silicon wafers are half the cost of traditional monocrytalline wafers manufactured using the traditional method. Solar cell wafers are only a fraction of the cost of solar panels, so the overall cost reduction for solar power is actually 10-20%.

The idea underlying the manufacturing process was patented more than 20 years ago but it was never commercially developed by the patent holders.

Monocrystalline silicon (c-Si) solar cells are the most efficient type of solar cells commonly used today, and multicrystalline solar cells which are made from molten silicon and cooled to harden, are less expensive than monocrystalline, but less efficient as well.

The production process of monocrystalline solar cells is extremely expensive due to the fact that an enormous amount of energy is required to manufacture them. A consequence of this is that it takes a long time for them to generate as much electricity as was used to manufacture the older monocrystalline type (15 years maximum, but it is not normally this long, modern solar cells average a couple to a few years).

The importance of this is mainly dependent on the source of energy used to manufacture them. If the energy source is coal, then it is a considerable problem, but if the energy source of nuclear, then it is not very important. Another factor to consider is the energy source that the solar cells would replace.

How much pollutant and CO2 emissions they ameliorate is also dependent on how “dirty” the source of energy they are replacing is. Coal is a good energy source to replace. If they are replacing nuclear power plants, however, then it doesn’t really help emissions. Multicrystalline solar cells are manufactured by a less energy-intensive process involving melting silicon and then cooling it.

Suntech CEO Stuart Wenham says that production can be scaled up quickly because it is compatible with existing wafer processing factory machinery and he also expects the photovoltaic (solar cell) industry to adopt similar manufacturing methods in the next two years.

h/t Technology Review

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3. Kyocera Sets New Solar Cell Efficiency Record

Image Caption via Technology Review; Credit: suntech-power.com