In recent years, labor costs and land costs have kept increasing. The same thing happens even in countries like India, due to economic development and the scarcity of installable land. Looking at the bulk commodities such as Aluminum(mounting brackets) and cables used in the construction of solar power systems/solar power plants, you'll find they are also in a rising trend.
In such a large pattern, in order to continue to reduce the construction cost of photovoltaic solar systems, in addition to lowering the price of solar modules, the most effective way is to improve the efficiency. In some solar power systems, the area-related cost accounts for half of the total project cost, and the cost reduction effect brought by the future efficiency increase will be far greater than the result of merely reducing the solar panel price.
Area-related cost refers to the cost directly related to the square meters of the solar panels, during the construction of the solar power plants. For example, transportation, installation, cable, mounting, land, and operation & maintenance costs are all area-related costs. Selecting high-efficiency solar modules can not only reduce the area-related cost of the initial investment but also save maintenance costs such as cleaning, cable replacement, mounting replacement, etc.
Area-related cost is based on a single solar module. Different types of solar systems (grid-tied solar system, grid/hybrid solar system, off-grid solar system), various construction areas, and diverse labor costs can result in significant differences in area-related costs. However, we find that the area-related cost is often between $80/piece and $119/piece. That is to say, during the construction of a solar system, the cost of transportation, installation, cable, pile foundation and land for a 60-cell PV module is usually more than $80. Therefore, decreasing the associated cost per piece has become an urgent issue that needs to be solved, and it is also the economic rationality basis for high-efficiency solar modules at a higher price.
Due to various ways of encapsulation, wafer quality, and cells, the rated power output(Pmax) of solar modules can be of vast difference. Today, the Pmax of conventional 60-cell polycrystalline solar modules is 275W. By contrast, Pmax of high-efficiency mono PERC solar panels generally reached 310W+, even up to 325 watts.
Let's select a solar power plant with an area-related cost of $80. We can get the area-related cost per watt of a poly solar module(CL-275P6-60 Series) is 80 ÷ 275 = $0.291; the associated watt cost of a mono PERC solar module(CL-310M6-60 Series) is 80 ÷ 310 = $0.258. The price difference is 80 ÷ 275 – 80 ÷ 310 = $0.033. It shows that high-efficiency solar panels have a lower area-related cost, which is the fundamental source of the reasonable price difference.
However, the above simple calculation formula has a significant drawback, that is, it does not consider high-efficiency mono PERC solar panels have the power generation gain of about 3 %. Empirical data support the gain of power generation, and its theoretical reasons are relatively clear, mainly due to:
First, high-efficiency mono PERC modules have a better performance in low light conditions. They can better absorb low light. It means the solar power plant starts working earlier and stops later, which is equivalent to a good comrade who works early and sleeps late every day.
Second, monocrystalline PERC solar modules have a lower operating temperature. And because of their higher conversion efficiency, the energy dissipated in the form of heat is less during the operation. We all know that high temperature is not conducive to the power generation. A module's general temperature coefficient is 0.46%, which means that for every 1-degree increase in solar cell temperature, the power generation will be reduced by 0.46%. However, the temperature coefficient of Coulee Limited's high-efficiency mono PERC solar module is 0.36%, which means when the temperature is increased by 1 degree, the power generation is reduced by only 0.36%. So lower operating temperature is another compelling reason for increasing power generation. It leads to a price premium of about $0.01 per watt.
Now let's consider the half-cell technology. When the conventional full-cell solar modules are shaded or dust-covered, the power output may drop to zero, and the probability of hot spot effect is significantly increased; While when the half-cell technology is integrated, a solar module can retain at least half of the power generation. After considering the gain of this part, there is another premium of about $0.005.
If the operation and maintenance cost is taken into account, we will conclude a surprising conclusion. The lower the efficiency is, the larger the PV arrays are, which also leads to a higher cost of cleaning and replacement. So for a piece of 60-cell solar module, it is reasonable for PERC monocrystalline solar module 310W to sell $0.048 more than the 275W polycrystalline solar module!
Don't forget we only assumed that the area-related cost is $80 when it is raised to $119 due to the increase in labor costs and land costs in the future, definitely the premium space will be more significant. The strength of applying high-efficiency solar panels is revealed. We can judge that high efficiency is almost an inevitable choice for the future.