Keeping Pace with Cost Reduction as Module Prices Continue to Decline
by Alessandro Fujisaka, Silicon Genesis, San Jose, CA USA
Published: August 12, 2010
The solar industry is expected to continue enjoying strong growth but based on declining prices. Over the past year, a combination of the global recession, breakdown of the financial markets, and Spain's cut in incentives contributed to the weak demand in the photovoltaic industry, increasing the inventory and pushing down the module ASP by ~50% from 3Q08.
These lower module prices demand companies to revamp their production techniques to keep pace with the price erosion and ASP will again be the most important driver for the industry in 2010. Falling silicon prices have helped lower the crystalline silicon cell cost, but the wafer substrate remains the major contributor to the overall cost. Silicon Genesis has developed an approach to cleave wafers or foils down to 20μm using less than 2g/wafer with no kerf loss providing the technical and financial ability to keep up with the manufacturing cost pressure. The approach is an evolutionary step to thinner wafers – in the 150μm to 100μm range – serving the market for the next 3-5 years, as well as a disruptive step enabling ultra-thin wafers below 100μm, and down to 20μm foils with a longer market impact, perhaps for the next 3-15 years.
c-Si module cost analysis
Crystalline silicon module ASPs have dropped significantly with the reduced poly cost has dropped to as low as $1.60/Wp at “best practice.” Advances in wafering have also contributed to lower manufacturing costs. By analyzing the c-Si Solar PV module ASP and cost dynamics , with current poly cost in Q2’10 at $58/kg, and more efficient usage of silicon at 6.5g/Wp, the silicon material cost still contributes $0.38/Wp. The module cost can help forecast the module ASP, especially as the industry adopts more normal price and cost down curves. With the silicon price expected to be <$50/kg by the end of 2010, the price is predicted to fall to $1.42/Wp exiting 2010. The total module cost, margin and ASP are represented in Fig. 1.
|Figure 1. c-Si solar PV module ASP and cost dynamics.|
Wafering cost reduction
In the wafering segment, the primary strategy is to minimize the costs by cutting thinner wafers at high yields while reducing the silicon lost during processing. Silicon Genesis’ kerf-free technology is a process that will virtually eliminate all waste when cutting materials needed to implement solar technology.
By comparison, in Fig. 1, the potential module ASP achieved using the new technology, at 150μm and 50μm, respectively, with the same gross margin points, can be seen. With today’s silicon cost at $58/kg, the reduced manufacturing cost could lead to a 36% reduction in module ASP. The Deutsche Bank analysis published in February 2010 indicates that at the low cost of silicon, the forecasted module ASP could reach $1.10/Wp. Using the same analysis, if adding the potential using kerf-free wafers, it could achieve a module ASP of $0.75/Wp comparable to some thin-film technologies. With this c-Si module cost and consequently price at these low levels, the focus shifts again to conversion efficiency and downstream. The improved conversion efficiency using crystalline silicon leads to lower and simpler balance of systems.
The BOS costs will become an increasingly larger portion of the total solar PV system cost. The reason is that a portion of the BOS costs are area-related and not efficiency-related. The potential cost reduction on area-related is much less substantial than the time used to install/build a PV system, which is heavily related to area usage. The result is that the efficiency (electrical conversion per area used) becomes the predominant cost of electricity production. About 5-7% cost reduction is achieved per point of CE improvement . The BOS cost savings with CE is illustrated in Fig. 2.
Figure 2. BOS cost savings with CE. SOURCE: Solar Vision Consulting
Kerf-free technology enables crystalline silicon to achieve thin-film technology costs while keeping the high conversion efficiency. The high CE gives lower BOS costs, lower area related costs (land costs, grading, etc.), reduced shipping costs, and reduced balance of plant (BOP), i.e., plant operation and maintenance.
Mono-crystalline wafers, which have the highest probability of achieving above 17%-18% average, will become a more competitive choice moving forward.
Another aspect of the new technology is the wafer quality that results from the precise ion beam implant technique. The process reduces or eliminates micro-cracks, which is one of the main causes of breakage in the cell; micro cracks also lead to broken wafers. Current cell production lines incorporate equipment for testing micro-cracks, which adds cost and complexity; with no full assurance of defect capture. Therefore, cell yield could potentially be improved with the new kerf-free material. The characterization of these ultra-thin wafers have demonstrated the enhanced properties inherent to this process and outlined in Table 1.
The cost/Watt advantages achieved by the new process will allow crystalline silicon to better withstand the competitive market pressures of other emerging technologies and will provide the basis for taking leadership positions in the PV industry as a result of lower manufacturing costs, higher material quality and greater conversion efficiencies.
Thin-film module prices are expected to experience a more moderate decline than c-Si module prices. Although the gap will narrow, the thin-film module cost and ASP will not be effectively challenged by c-Si modules unless a more aggressive approach is taken. Despite the silicon cost reductions, most of the c-Si module manufacturers will suffer margin compression as they compete with thin-film. High efficiency and lower costs are realized by the SiGen PolyMax technology, thereby offering a competitive and sustainable approach to challenge and surpass thin-film modules on cost and price.