The first thing we need to explain is what is the "soft cost" of photovoltaic systems, which can be explained by the following formula:
Soft cost = total cost - hardware (module, inverter, structural and electrical BOS) cost
Specifically, soft costs include costs such as land, labor, taxation, administration, and profits. From the figure below, it can be seen that the hardware cost of photovoltaic systems in the United States has significantly decreased over the past 7 years, and correspondingly, the proportion of "soft costs" has gradually increased.
Taking public utility level (large ground) photovoltaics as an example, in 2010, soft costs accounted for only 32% of the total cost, while in 2017, soft costs accounted for 41% of the total cost. In 2017, the soft cost of commercial facility photovoltaic systems accounted for 59%, while the soft cost of household photovoltaic systems reached a higher proportion of 68%.