In 2001, Silanex cooperated with China Sunergy to apply its thermal conductive adhesive into the concentrator photovoltaic module by taking the advantages of high thermal conductivity and stable chemical to effectively enhance dissipation performance and service life.
The C-Sunergy company is a world leading manufacturers of high-efficiency solar photovoltaic cells components, headquartered in Nanjing, Jiangsu Province. It is established in 2004, both by the chairman Mr. Lu xiuting and Ph.D. Zhao jianhua, world-record holder of crystalline silicon solar cell conversion efficiency. In 2008, C-Sunergy appeared in the market of U.S. NASDAQ with stock code: CSUN
The first and second generation of solar energy technology is to conduct the photoelectric conversion by utilizing crystalline silicon and thin film battery, which has been widely applied. The future third technology is to use the optical element to gather the sun light for generating power. It is called concentrated solar technology.
Different from the traditional silicon and thin film, HCPV has the following significant obvious advantages
1. High conversion rate: compared with the traditional energy, concentrating photovoltaic energy conversion efficiency is reached to 30%, which has been equal to the first generation of nuclear power plants.
|System efficiency||Energy exchange efficiency|
|Thin film type||7%-9%|
|Crystalline silicon type||14-17%|
|The first nuclear power plant||30%|
2. Huge potential for cost reduction: compare with crystalline silicon and thin film solar technology, the construction costs of CPV is 3~4$/Wp, which has no advantage. But, following the expanding of production scale, battery efficiency and module improvement, costs would be dropped sharply.
3. Given the same generating capacity, CPV power plant covers a smaller area. Further, due to the angle change of tracking system, the shadow area alternation would not affect the ground ecology.
4. The process of CPV generation needs almost no water, only a small amount for cleaning the glass shell. It obviously has the water economy advantage.
Given the CPV solar power system principle is relatively simple, why in the world have not a few companies to make the stable and inexpensive power systems?
In principle, the higher concentrated ratio, the cheaper cost will be. But the concentrated way will appear following problems:
1. Put the monocrystalline silicon under high concentration
Although gallium arsenide can bear 1000 times light intensity, but it is very expensive and highly toxic. It is impossible to dramatically reduce manufacturing costs. It is also impossible to massively use due to the international environmental protection. The last option is monocrystalline silicon. The monocrystalline silicon normally only can bear 3~5 times light intensity. In the field of CPV，3~5 times of concentration almost can reduce no cost. In order to achieve 10 times concentration, we must use special monocrystalline silicon.
The temperature of ordinary silicon light panels would climb to 75 degrees above in summer noon; get blister under a period of time of 2 time’s strong sunlight, in 10 minutes under 5 time’s strong sunlight and in 5 minutes under 10 time’s strong sunlight. The solar cell will be getting oxidation after blistering and efficiency would be greatly reduced in a very short time. Also due to the uneven heating, cell cracking would frequently happen. The system like this is completely unusable. If we use aluminum or copper heat sink for natural cooling, it would be more expensive than silicon cell. If we use air cooling, it would cost a lot of electricity. Cooling fan has short service life and low reliability. The error checking and redundancy setting is a must if we want to achieve high reliability, which will increase the cost several times. If fan stops working in summer noon, the whole silicon photovoltaic panels may be burned completely. If we use water cooling, in addition to the cost of electric power, it’s not cheap either. More joint points and water pump lead to more failures. Water cooling is not much better than fan cooling. Although water cooling has higher efficiency, it is still impossible in solar energy due to its failure feature. Cooling ability directly determines reliability and suitability of the product. No matter how high the conversion efficiency is, without enough cooling ability will cause fast oxidation of chips, fast drops of conversion efficiency, product performance and even equipment damage.