Color Signs For Maturity

The International Technology Roadmap for Photovoltaic (ITRPV) is adding new colors to its 2016 study. The latest version of the well-known PV report that annually tracks the development of PV technology and equipment has been adapted to a color code to indicate the maturity of technologies, at least wherever it is applicable. The first version of the 7th ITRPV edition, which is published by the PV Chapter of the German Engineering Federation (VDMA), was released in March 2016, then updated in the summer, while the lastest update has been introduced today by one of the lead authors, Markus Fischer from Hanwha Q Cells, at the Asian PV conference PVSEC-26 in Singapore.

The change in update version is that ITRPV is now indicating the status of the technology in four different colors as follows.

• Grey – Industrial solution exists, and is being optimized in production
• Yellow – Industrial solution is known but not yet in mass production
• Red – Interim solution is known, but too expensive or not suitable for production
• Purple – Industrial solution is not known

For example, regarding wafer thickness reduction, the earlier version indicated that 180 µm is still the preferred thickness of wafers used in mass production, mainly to keep breakages rates low. It is assumed that the thickness of multi wafers will slowly approach a minimum value of 150 µm within the next years. On the other hand monocrystalline wafer thickness would take a faster track in reducing the thickness first to 160 µm and then further down to 140 µm by 2026. So the part on time scale of the x-axis for mono wafers down to the thickness of 160 µm is marked grey, indicating an industrial solution exists. For a mono wafer thickness from 150 µm to 140 µm the x-axis (2022-2026) is marked yellow, implying that an industrial solution is known but not yet in mass production.

It’s the same system for future module technologies with regard to changing wafers. While industrial solutions module processing solutions exist for using wafers down to 150 µm (grey until 2019), the available technologies are not yet suitable for mass production of thinner wafers (red).

However, using a color code for indicating maturity of production technologies and processes is not a new idea. ITRPV has been doing this from the beginning, the only exception was this year’s 7th edition. The update brings it back on to the track. Nevertheless, it is worth taking note of the topics that have been adapted to the color regime.

Apart from trends on wafer thickness reduction, 7 other topics are now adapted to the color code:

• Reduction in silver consumption per cell
• Trends in increasing silicon ingot weight
• Forecast for improvement in throughput of crystal growth equipment
• Expected development in throughput of cell production tools
• Anticipated reduction in recombination currents
• Expected increase of emitter sheet resistance
• Predicted finger width reduction and improvements in alignment accuracy of screen printers

Except for adding new information about maturity, ITRPV has not changed any of its forecasts. All prediction remained the same. A forecast update will come with the 8th edition, which is scheduled for publishing in March 2017.
The updated 7th ITRP edition can be downloaded here