Solar Production Shifts Into High Gear

Solar automation in a nutshell
• Cell soldering, module conveyance is manual in plants up to about 25 MW.
• Full automation becomes practical in plants above 50 MW.
• Solar wafer thickness is unlikely to go much below 160 microns.

Resources:
Next Big Challenge for PV Makers:
Wafer Handling, Machine Design,
7/8/08, tinyurl.com/5ndanc

National Renewable Energy Lab
solar research home page,
www.nrel.gov/solar/

Rockwell Automation,
rockwellautomation.com

Spire Corp., Solar Operations,
spirecorp.com/spire-solar/index.php

The German solar maker Q-Cells AG has an interesting product. It is a multicrystalline solar cell roughly 7 in. square purported to convert about 14% of incident sunlight into electricity. This makes the device among the most efficient in its class.

You might think Q-Cells is happy with this state of affairs. You’d be wrong. The firm figures its costs are too high and says it aims to slash them by 50% within two years. In that regard it is pursuing avenues that include increasing the efficiency of its production and figuring out ways to make its processes more standard.

Q-Cells’ worries about manufacturing costs mirror those of other photovoltaics producers. Though the PV market is booming, the technology is not cost competitive with electricity generated by fossil fuels. Government incentives level the economics, but PV makers view these as unreliable. So to both get their costs down and meet mushrooming demand, they are automating production and trying to get their manufacturing operations into the 21st century.

“In some ways, their processes are not completely optimized,” says U.S. National Renewable Energy Lab Principal Project Leader Richard Mitchell. Mitchell coordinated a manufacturing R&D project credited with significant reductions in the production cost of PV modules. “Solar production processes are refined enough to make high-quality salable products but they will continue to be optimized over the next decade to get higher yields and lower costs. It is an evolution similar to what large manufacturers like automakers go through.”

Turmoil in PV manufacturing has brought a need for integrators experienced in automation. “PV makers have been in a rush to scale up production because they have presold the inventory of every plant they can build,” says Rockwell Automation Industry Solutions Manager for Solar and Semiconductor Bates Marshall. Rockwell has developed automation equipment for several main-stream thin-film PV suppliers. “PV thin-film people are focused on speed of integration, ramping up production, and expanding to support factories globally,” he says. “This contrasts with the semiconductor industry where there is still a great deal of invention going on in control systems because of a perception that more benefits can be had by inventing automation technologies.”

One factor complicating automation efforts in PV is that “In thin-film, manufacturing processes of different suppliers are completely unique. That’s why there are so many of them,” explains Marshall.

There is more commonality in crystalline production processes and today, they are more mature than thin-film lines. “The layout of different PV module assembly lines would look a lot like the ones we sell,” says Spire Corp. Sales and Marketing Vice President Mark Willingham. Spire manufactures equipment for making PV modules as well as turnkey PV-module production lines. It says about 90% of all PV manufacturers have pieces of its equipment in place.