In the five-year, multi-million dollar program, BP (London) and Caltech (Pasadena, Calif.) will explore a concept based on growing silicon by creating arrays of nanorods, as opposed to the more convention method of casting ingots and cutting wafers.

Nanorods are small cylinders of silicon said to be 100 times smaller than a human hair. A solar cell based on an array of nanorods will be able to absorb light along the length of the rods by collecting the electricity generated by sunlight more efficiently than a conventional solar cell, according to claims made by BP and Caltech.

The program will also investigate uses of nanotechnology to create designer solar cell materials — such as nanorods and nanowires — in order to change the conventional paradigm for solar cell materials.

It will also investigate approaches to create silicon-based single junction and compound semiconductor multi-junction nanorod solar cells by using vapor deposition synthesis methods.

The effort faces some major challenges. "Nanorod technology offers enormous promise; however, like any new technology, challenges remain to make it commercially viable at scale," said Lee Edwards, BP Solar's president, in a statement.

BP Solar is part of BP, one of the world's leading energy companies. BP Solar is a global company with over 2,200 employees focused on developing solar cells.

The unit has four major manufacturing plants, which are located in Spain, Australia, India and the United States. With more than 90-megawatts (MW) of solar-cell fab capacity right now, the company aims to more than double its current production to 200-MW by the end of 2006.

In April, Santander and BP Solar announced what the organizations claimed was the largest solar power project in Europe. The agreement reached between the two companies will allow for the construction of up to 278 photovoltaic solar power installations in Spain with total capacity of 18-to-25-MW. The construction of the plants was supposed to begin in May 2006 and is expected to conclude in December 2007.

Not long ago, solar energy was considered a niche market. Now, solar-cell vendors are scrambling to expand their capacities to meet huge demand from homes and businesses worldwide. Companies that have recently announced new and massive solar-cell production plants include Energy Conversion Devices, Evergreen Solar, Sharp, SunPower and Suntech.

Last week a startup originally funded by Google Inc. announced a $100 million financing package and set plans to build what the company claims as the world's largest solar-cell manufacturing facility in California.

Presently in pilot production in its Palo Alto, Calif.-based facility, the solar-cell startup, Nanosolar, has started ordering volume production equipment for use in a factory said to have a total annual cell output of 430-MW once fully built out, or approximately 200 million cells per year.

Indeed, solar is here today, but the technology is at about three times the cost of conventionally generated electricity However, thanks to advances in conventional and thin-film technologies, some believe that the cost of solar will be on par with that of conventional electricity within 10 years.