After the 531 New Deal, the focus of the photovoltaic industry is the process of “parity on the Internet” and the decline in system costs. In the past 10 years, the cost of photovoltaic modules and photovoltaic systems has dropped from 30 yuan/W and 50 yuan/W to the current 1.8 yuan/W and 4.5 yuan/W, both of which have fallen by more than 90%. The chart below shows the price changes of components and inverters for the last 8 years.
图: The price trend of PV modules and inverters in 2011~2018
Someone can't help but ask, in the case of rising costs such as steel and cable, how much space will the PV system cost have in the future?
At the current level of 4.5 yuan / W, the absolute value of the cost of photovoltaic system declines little space, but there is still a certain amount of room for decline; at the same time, in the future, photovoltaics must achieve parity online, more depends on technological progress to achieve a significant increase in power generation hours Therefore, the cost of electricity is reduced.
I. The space for PV module cost reduction
PV manufacturing is a very fast technology industry. An advanced technology and advanced equipment may become backward production capacity after three years; the old production line will be replaced by a new production line with better quality products and a sharp drop in prices. In the near term, the cost of PV modules in the future will mainly come from three aspects:
1. The cost of silicon materials will drop
As the equipment and energy prices of domestic silicon materials companies continue to decrease, the level of automation will be greatly improved, and the production will be carried out at different stages. The cost of silicon materials varies widely. In the future, with the advancement of technology, there is still a certain room for decline in the price of silicon materials.
2, the thinning of the cutting technology
From 2017 to 2018, the entire industry completed the technical transformation and upgrading of mortar cutting to diamond cutting. As the diamond wire becomes thinner, flaking becomes a trend. In 2016, the thickness of mainstream silicon wafers is still more than 200μm. At present, 180μm is the mainstream, and 160μm and even 150μm are also beginning to appear in the market. Wafer flaking directly causes an increase in the amount of wafers per unit of silicon, resulting in a decrease in the price of the wafer.
3, the high conversion efficiency brings about the reduction of
In the push of the leader, new technologies in the battery chip, component packaging, endless, PERC, SE, MBB, half-chip, tile, double-sided, etc., components The conversion efficiency has increased dramatically! This will inevitably lower the packaging cost of PV modules.
In summary, based on the most advanced technology level of each link, there is still a certain room for decline in the price of components in the future.
二, PV system cost reduction space
In addition to the photovoltaic module's own cost, thanks to the improvement of the design level, the application of high-efficiency components, the cost of photovoltaic system also showed a significant decline.
1. Optimizing system design will become the main direction of cost reduction
In recent years, the design level of photovoltaic power plants has been greatly improved. The obvious design technology improvements include:
1) The increase of the size of a single power generation unit
Early PV power plants were designed according to the scale of a single power generation unit of 1MWp. In the last two years, the single power generation unit has been increased to a scale of 1.25 MWp; in some scenarios where the 1500V system is applied, the scale is increased to 2.5 MWp. The increase in the size of a single power generation unit reduces the amount of engineering to a certain extent, thereby reducing the cost of the project.
2) Over-design is gradually being widely used
Early PV modules: The inverter's capacity ratio is designed according to 1:1, causing the inverter to be fully loaded for most of the time, with low utilization.
At present, many projects have adopted the design concept of over-matching in the design, at least 1.1 in the I and II resource areas, and even in the III IV area to 1.2 or more, improving the utilization rate of the AC system such as the inverter and the box change; Thereby achieving the goal of reducing the cost of a single tile.
3) Optimum design of array spacing and dip angle
Compared with traditional manual calculations, intelligent design software is widely used. Therefore, the use of various cables and steel materials is more accurately calculated, reducing the amount of redundancy, thereby saving the cost of the auxiliary materials.
At the same time, in the case of increasing land cost ratio, unlike the traditional design concept of optimal dip angle, the current design of power station design adopts the design concept of “optimal economic spacing and inclination”,
Over-design: At least 1.2 in the I II resource area and at least 1.4 in the IIIIV area, maximizing land and cable costs.
2, high-efficiency components drive down the cost of BOS
The same scale of photovoltaic power plants, using high-efficiency components compared with the use of inefficient components, except for components, inverters, transformers and other devices calculated by capacity (including The amount of the combiner box, AC and DC cable, bracket, foundation, bridge, monitoring and communication, etc. is the same; the amount of construction (road, cable trench excavation, etc.) is the same.
If the cost of equipment and construction costs other than components, inverters, and transformers is called BOS cost, the higher the efficiency of the components, the lower the cost of the single-watt BOS; and, due to the land components (roof rental) The higher the cost and the more difficult the construction, the higher the cost of BOS, so the advantage of using efficient components is more obvious.
三, Decrease in the cost of photovoltaic power
As mentioned above, the current cost price of photovoltaic system is already very low, and the absolute cost of the space is not large; but to achieve parity online, it is necessary to reduce the cost of electricity. The figure below shows the calculation formula for the cost of electricity.
中,
I0 : Initial investment of the project, VR: residual value of fixed assets, An: operating cost of the nth year,
Dn: depreciation of the nth year, Pn: interest of the nth year, Yn: n years of power generation
With the advancement of technology, the potential for power generation hours of power stations is very large, which can greatly reduce the cost of electricity.
1. Increased system efficiency
The efficiency of the early PV power plant system was around 78%.
Thanks to many factors such as design optimization, construction quality and equipment quality improvement, high-efficiency component application to reduce line loss, etc., new power plants can basically achieve system efficiency of more than 81%; equivalent to more than 3.8% power generation. That is, the cost of electricity is reduced by 3.8% or more.
2, tracking technology application
Compared with the traditional fixed type, in different locations, the use of fixed adjustable, flat single-axis tracking can increase the power generation by 5%, 10% to 15%. Moreover, the current fixed-adjustable, flat single-axis tracking technology is very mature. The power generation capacity is increased by 10%, and the electricity cost can be reduced by about 11%.
Therefore, using advanced installation methods, you can increase the amount of power generation and reduce the cost of electricity. Among the third batch of front-runners, a large number of projects have adopted fixed-adjustable, flat-axis tracking technology.
3, double-sided component application
Under different working conditions, the back side of the double-sided component can achieve 10~20% of the front power generation, which is equivalent to increasing the overall conversion efficiency of the component by 10~20%. Since both components and inverters are currently used, the ratio of capacitance is 1.1 or more. The application of double-sided components can improve the utilization of AC systems such as inverters, while significantly reducing the cost of BOS.
In summary, thanks to the system efficiency improvement, tracking technology and the application of double-sided components, under different working conditions, the new power station can increase the power generation by about 20% compared with the early power station, so that the project can be powered. The cost is reduced by about 20%.
四, Conclusion
Through the above analysis, we can see that
Due to the improvement of the technical level of the upstream manufacturing links, there is still a certain room for the future of components.
By optimizing the design of the PV power plant and using high-efficiency components, the cost of BOS can be reduced.
Thanks to the system efficiency improvement, tracking technology and the application of double-sided components, under different working conditions, the new power station can increase the power generation by about 20% compared with the earlier power station, thus reducing the electricity cost of the project.