Flexible photovoltaic (PV) modules are thin and light - and what they lack in efficiency is being offset against constraints inherent in conventional crystalline PV modules. Suppliers of second generation, flexible, thinfilm modules and emerging organic solar cells are targeting the opportunities.

Thin-film PV technology has been undermined in recent months by crystalline silicon PV. China's investment in PV manufacturing has driven down the prices of silicon PV modules.

This, coupled with generous government subsidy schemes around the world, means the market for PV is 80% crystalline silicon. The trend has countered much of the impetus that was previously driving the thin-film PV industry. Cell efficiencies are much lower and modules themselves are more expensive than crystalline silicon.

The result is that the solar industry is re-evaluating alternative PV technologies. New technologies cannot compete on cost alone. As we are seeing with OLED lighting, the differentiating factors of a new technology have to be demonstrated to those markets that will value them.

A substantial proportion of the BIPV rooftop market cannot be met by mainstream, rigid and glass-encased PV modules, because many roofs are not able to support their load.

In 2012 US-headquartered Dow Chemical will start supplying roofing tiles - or shingles as they are called in the US - incorporating Global Solar's flexible PV technology.

The solar shingles can be fixed onto roofs like conventional shingles and easily connected to turn the roof into a solar array. These products are not new, but previous PV tiles, using amorphous silicon laminates, have had limited success, partly because efficiencies were too low.

Commercial buildings, particularly industrial sheds, are ideal. The metal elements used to construct the walls and roofs can be laminated with PV films or coatings in the factory. The approach is potentially more cost-effective than buying and installing the PV module separately.

Other OPV companies are also exploring BIPV. Heliatek, in Dresden, Germany, says its modules will go into production in a roll-to-roll process on low-cost foils by mid-2012.

This article appears in full in Volume 4, issue 3 of +Plastic Electronics magazine. To read this article, along with more high-value, exclusive content, subscribe to +Plastic Electronics magazine.