Category Power for the World

Polarization

We had no idea what the problem was. I put together a team to focus intently on the issue. It was scary indeed. $150 million invested and perhaps it was all going to crash down around us. After working around the clock for several months, we had identified the cause of the problem, and found a solution. Very high efficiency cells are susceptible to a phenomenon we discovered, which we named polariza­tion. It had heretofore not been observed because it only occurs when modules are installed in a large system that generates high voltages. The incredible thing was that it only occurred when our high efficiency modules are operating at positive voltages compared to earth, and not when negative...

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Becoming a Manufacturer

Now we had to figure out how to transfer our one-sun cell design into high vol­ume manufacturing. The cells would have to be made at low cost and with high manufacturing yield. Cypress helped here by installing our pilot production line in an existing Cypress factory in Round Rock, Texas. We worked closely with experienced manufacturing personnel. The idea was to quickly inoculate our team with a manufacturing mentality, and train them in the latest in manufacturing methodology. Many of our engineers moved to Texas temporarily to participate in this project, making big sacrifices in order that we succeed. By the spring of 2003 we had cells from the pilot line that met our requirement of 20% conversion effi­ciency. SunPower announced its new high efficiency PV module in May of 2003...

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Goodbye Concentrators

We also planned to install a large, 20 kW concentrating dish on the Cypress campus as a test of our concentrator concept. There emerged a problem, however. The dish would require a large set back covered with only gravel to guard against fire caused by reflected light in the event that the dish was not pointed at the sun.

That was a problem in that the dish was to be in the parking lot. The dish was also rather large, in fact as tall as the three-story Cypress headquarters building. It would be a visible landmark for much of northern San Jose, California. This is to be compared to the non-concentrating system on the already roof that provided 15 times the power, and was invisible from the ground...

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Cypress

TJ immediately grasped the proposition — getting into the power generation business turning sunlight into electricity with silicon solar cells. Cypress was, after all, a maker of silicon chips and understood that material very well. He instinctively knew that PV was going to be a big business, and that silicon was the path to success. He liked the concentrator idea too. Cypress had been forged into a very lean and capable manufacturer by 25 years of competition in the brutal computer chip business. He quickly sized up the PV industry and realized that the manufacturing sophistication of the existing companies was quite limited. TJ felt that by combining our cell technology with Cypress’ manufacturing knowhow, we could be a winner...

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A New Plan

We knew that the Helios project was just that, a project that would soon end. Then where would we be? Our existing investors had become tired of SunPower. Armed with our low cost, high efficiency cell idea we decided to once again look for new investors. We put together a business plan that encompassed all of our products — optical detectors, concentrator cells, and one-sun cells — and began talking to venture capitalists and investment bankers.

Concentrators were included in the plan because we had kept a small con­centrator cell business going, mainly providing cells for the big parabolic dish concentrators that Solar Systems, Inc., in Australia was building. We also had worked on a large R&D grant from the National Institute of Standards...

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Project Mercury

Since NASA was interested in making lots of solar powered airplanes, they asked us what we could do to decrease the cost.[153] It seemed $6 million for each airplane’s cells was too much. We had gained valuable experience in making so many high efficiency solar cells for Helios, and so the engineering team launched a project into how we might use that experience to decrease manufacturing cost. This proj­ect, which was headed up by one of our engineers, Dr. Bill Mulligan, was named

Project Mercury. It was a very successful project, exceeding our wildest expecta­tions.

We had hoped to decrease the price from $200 per watt to $60 per watt...

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Airplanes

SunPower’s next PV breakthrough came from NASA. NASA was developing a solar powered airplane. Their vision was for a solar powered "eternal aircraft" that could stay up for extended periods doing things like monitoring atmospheric pollution. For the concept to work, they needed the highest possible efficiency, SunPower’s specialty. NASA knew about us from the publicity surrounding the

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Figure 4. NASA’s solar powered airplane over Hawaii.

Honda Dream, and we began making cells for their airplane, Helios. Fortunately, Helios was much bigger than a car, and needed lots of cells. In fact its wingspan was the same as a Boeing 747’s. Over the period 1997 to 2000, SunPower made 60000 high efficiency cells for NASA...

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The PV Business Takes Off

Meanwhile, SunPower was being left behind in the PV business. The concentrator market had not materialized, but the conventional solar module business had. Early on, most PV modules were used to power remote needs such as telecommu­nication towers on mountaintops, now a new market began to emerge. This was residential and commercial roof mounted systems that were connected to the power grid. This proved to be PV’s next killer application. The market began growing quite rapidly after Japan instituted an incentive program for residential roofs. At that time, the leading PV companies were all owned by major oil compa­nies. Rumor had it that they were losing money on PV, but then they had lots of money to spare...

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