Despite their allure, alternate energy systems have really not been able to displace conventional, non-sustainable, polluting or hazardous sources like coal, petroleum or nuclear. Reasons are cost and scalability. Take solar energy. It is estimated that several times the planet’s total energy need arrives from the sun but costs of gathering and effectively storing it are prohibitive.

Nanosolar Inc, in California, USA began with a checklist of seven stumbling blocks in the way of solar energy’s success and has in 5 years of work, been ticking them off as overcome. It is now ready for wide commercial sales.

What was the state of solar technology that Nanosolar has improved on? The first generation technology used bulky, brittle and expensive silicon wafers to convert solar radiation to electricity. Costs were so prohibitive that it never amounted to much more than proof of concept. The next generation thin-film cells used much lesser quantity of semi-conductor material but the fabrication method of vacuum deposition resulted in low yields and high costs. Fragility continued to be an issue. Neither approach was amenable to large scale production.

Nanosolar’s approach is to literally print solar cells on continuous rolls of flexible, inexpensive substrate. It begins with Copper Indium Gallium Diselenide [CIGS] , a semi conductor material proven in the thin-film cell. Particles of CIGS are dispersed in the ‘ink’ and because of the nano-scale they maintain the element-level ratio required for photo-voltaic action. At nano scale, photovoltaic semiconductor quantum physics occurs. The cells are able to abstract energy from a broader spectrum of solar radiation than in the earlier cells.

With this approach Nanosolar has achieved lower cost of semiconductor and substrate materials, nearly nil rejection rate of produce, continuous production with least human error and economies of scale. It’s a breakthrough in fabrication technology. Nanosolar is building a large production facility and mass sales will begin this year. It plans to make roofing panels with pre-installed solar cells. They will also sell flexible solar cell sheets. Because these cells are bendable one can conceivably unroll a carpet of cells on a desert and draw power from it.

You can evaluate the maturity of their business from the fact that Google’s legendary founders spotted it in 2002 and became angel investors. A senior executive from IBM joined them and Nanosolar has effortlessly raised $100 million to build a factory. It is targeting sales of $100 billion by 2020. Not inconceivable at all. Nanosolar