CEO interview: Innovations in solar technology; PERC the new PV benchmark

Looking at the new technologies featured in this special publication, what do you think it says about the market?

First of all what is noteworthy about this development is that finally manufacturers are willing to invest into upgrades of their production equipment at the production-scale level. So while the new technologies behind the products being showcased at the Intersolar Europe trade fair have already been available over the last one to two years, their usage was mainly confined to pilot lines and evaluation purposes. This year, we begin to see the shift that the industry is deploying these technologies across a significant portion of their production volumes.

What has triggered companies to move forward and roll out these new technologies on a broader scale?

There are a number of reasons why we see this happening now: increased capacity utilizations have meant new capacities had to be brought online. These new production lines are obviously equipped with state-of-the-art production tools that are required to manufacture these higher efficient cells and modules. To a certain extent, the trade disputes between Europe and China, and the U.S. and China, respectively, also had a role to play. In reaction to the imposed import duties or minimum price requirements, a number of Chinese manufacturers decided to set up new production capacities outside China.

Furthermore, an important aspect that aided these investment decisions was the improved profitability many manufacturers were able to achieve over the past two years. Without this improvement, many companies could not have afforded the investments in new or upgraded production lines. And finally, the manufacturers had thoroughly evaluated these new technologies and came to the conclusion that the benefits clearly justified the necessary investments.

Why do you stress this latter aspect, hasn’t this always been the case in the industry?

As long as new production lines could easily be financed, manufacturers were willing to adopt and experiment with new production technologies at a much earlier stage. Yet the industry had to realize that in a number of cases these innovations didn’t achieve the benefits expected. If you look three to four years back, the selective emitter technology was considered an important improvement and it was believed all new cell lines would adopt this technology. With the improvements achieved in the meantime, with the conventional homogenous emitter technology, the relative advantage of the selective emitter technology is so small that this technology is becoming less and less important in the market.

How do you judge the level of innovation at the cell and module manufacturing stage in the new module types showcased in our publication?

The majority of the increased power output that the new modules exhibit is achieved at the cell level. There are two or three examples of modules that also sport innovations at the module level, which I find very interesting (see: #9 in the array technologies guide), but the major boost in terms of increased power-ratings of the modules, comes from advances in the cell technology. Examples are the wide spread adoption of PERC technologies, or new wiring concepts that yield an incremental energy output boost.

PERC is also unavoidable when looking at new module concepts on the market. What do make of PERC technology rollout at present?

Larger manufacturers are rolling out PERC across the entire production (see: #36 in the array technologies guide), but I would assume that this year the percentage of PERC cells will still only reach around 10% to 15% of all cells being produced. So PERC is not the standard yet, but it is being deployed rather quickly meaning that over the next two years this will be the new benchmark technology and 60-cell modules will have 270W to 285W and above for multicrystalline modules. Monocrystalline modules using advanced PERC cells will result in modules with up to 320W.

Looking at new cell lines, though, PERC must have extremely high penetration?

Absolutely. I doubt that any manufacturer investing into new lines would do that without some kind of advanced cell technology. I assume that up to 90% of all new cell lines include this type of technology or other high efficiency cell concepts.

You mentioned new cell interconnection technologies. It appears that the move to three, four or five busbars is also becoming much more common. Do you think it too will become something like the new standard?

I don’t see any reason why the trend to higher numbers of busbars shouldn’t spread out. There was one patent issue regarding three busbar cells, but I am not aware that there is a patent issue with four or five busbar cells.

From a physics point of view, you could actually ask why this technology took so long to hit the market. This technology actually could have been applied already quite some time ago.

Was it that manufacturers simply weren’t willing to invest even the rather limited sums required to make such technological adaptions, because they were selling at losses?

Besides struggling economically, the cell manufacturers also had to be convinced that the pastes and the screen printing technology were suited for these modifications. The module assembly lines also had to be equipped with new stringers when changing from standard cells to cells with four or even five busbars (see: #45 in the array technologies guide). So the benefit in higher power output had to be significant enough to justify this investment.

One of the technologies featured is a bifacial module, with SolarWorld presenting its first commercial bifacial module at Intersolar (see: #50). What do make of the prospects for bifacial technology?

To me bifacial modules are more a byproduct of going to glass-glass modules. There is a good argument for going to glass-glass modules (again), because of the higher long term stability of the module. So if you aim for more than 20 years of durability, then going to glass-glass is not a bad idea. If you have a glass sheet on the back, then going to bifacial can make sense, although it depends on where the module is being installed. The benefit of a bifacial module depends on the level of ambient light and back reflectance that impinges on the rear side of the module.

You have to bear in mind that bifaciality comes at a price. So I’m not entirely sure whether bifacial modules will become such a commonplace technology, because I would believe that for many installations, the extra price you have to pay for processing the rear side is not necessarily recuperated, if you don’t have special situations where there is enough light being reflected to the backside of the module.

A lot of the technologies featured in the guide tend to be high-end, high efficiency modules, but of course that is not the bulk of the market. Is the high efficiency module market one that is important for manufacturers to be involved in?

It’s really important for manufacturers to be active in the high efficiency field. The price curve this whole industry is aspiring to was mainly driven by reducing the costs on a per-unit basis over the past three to five years. This was mainly achieved by negotiating lower material prices and to a certain extent by minimizing the material consumption (i.e. reducing the silver content in the pastes, using thinner wafers, etc.). Everybody in the value chain had to sacrifice their margins in order to come up with the cost reductions imposed by the market, but for two years now there were no further margins that could be sacrificed. So the next step for lowering solar’s LCOE really had to come from increasing the power output-per-area of the module, which means getting a more efficient cell into the module. These cost reductions are therefore technology driven. We don’t expect that module prices have bottomed out, on a per-Watt price.

Yet technological advances obviously take more time than simply negotiating with a supplier about the price for the input material. Technologies have to mature sufficiently so that they are fit for broad market adoption. High efficient cells and modules are crucial even for large power plants and not only in space-limited situations. BoS savings through higher output out of the same number of modules are important levers to further reduce solar’s LCOE.

Looking across the modules featured, were there any standouts?

I would like to highlight that in some of the modules there is not just one or two innovations, but in fact a number of innovations combined into one product (see: #9, #31 & #32 in the array technologies guide). I believe it is a good sign to see that technological advances are gaining more traction in the market.

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