**4.3. The economic potential of OPV technology**

One concern regarding the OPV technology is that how cheap the electricity generated by this renewable technology can be. More anxiety appears after the business failures of endeavors in the OPV market [147,148]. As a matter of fact, in the past years only a number of companies (Solarmer Energy Inc., Ossila, DyeSol, Heliatek, G24 Power, Eight19, Mitsubishi, Plextronics, Sharp Solar, Solaronix, SolarPrint, etc.) have ventured into the OPV technology related business, and are struggling to survive in the market. A number of articles have addressed the

**Figure 10.** Top: A plot of the power conversion efficiency versus the active area. Bottom: The PCE values obtained ver‐ sus the publication year. [30] Copyright Elsevier 2013.

economic potential of OPV technology to estimate the cost of the OPV electricity [4, 27-29, 149-150]. One key factor that dominates the cost is definitely the power conversion efficiency. Figure 10 shows the PCE values of the reported OPV devices vs. the area (top) and the year (bottom) by Krebs et al.[30] It is found that most of the highly promising efficiency data are only achievable with a device area < 1 cm2 . Furthermore, even though there are promising efficiency data (~7-10%) of some hero polymers, the majority of the research work exhibits a power conversion efficiency of less than 3%. As the area of the solar cell device increases, the efficiency is expected to be lower. With the current efficiency number for large scale OPV modules (< 3.5%), the applicability as mainstream power generation technology is rather dim. Some potential market and niche products for OPV technology include portable, low weight charger for electronics, PV covered uniforms, backpacks and tents for military usage and OPV integrated windows and walls. One intriguing idea about OPV usage is to serve as top cell in a tandem device with an inorganic bottom cell [151]. The tandem cell design strategy for all organic based materials has been proven efficient to improve the power conversion efficiency [22,24]. Key to the success of this tandem organic/inorganic strategy is the development of OPV modules with comparable lifetimes so that the technology can be used in a time of 5-10 years range. Another aspect is the energy pay-back time. For crystalline silicone PV technology, the energy pay-back time is estimated to be 4.12-2.38 year while for OPV it is about 2.02 to 0.79 year [28]. An even more optimistic estimation of the energy pay-back time of OPV technology is only 1 day [4]. As currently all promising data about OPV technology come from research labs and theoretical work, it is still difficult to conclude on the future and fate of OPV tech‐ nology. Efficiency and stability are two major obstacles, but may also become opportunities for new business players.
