This proposal aims to sponsor a workshop that will explore new paradigms for stimulating innovation and creating industrial-academic partnerships in the field of photovoltaics. The participants will include experts and leaders in photovoltaics research and product development from universities, large companies, small firms and national laboratories. Through a combination of invited talks and breakout sessions, the participants will brainstorm the future technical emphasis in photovoltaics, build networks for potential partnerships and collaborations to accelerate technology transfer from academia to commercial market, and propose new strategies to foster future collaborations among universities, large companies, small firms and national laboratories.
Broader Impacts
The broader impact of this project will be the potential to serve as a catalyst for stimulating innovations in photovoltaics. Maintaining a leadership in solar industry not only will benefit the environment, but also create more jobs domestically. The major challenges that hinder the wide adoption of solar electricity are the high cost, low manufacturability and/or non-abundant sources of the raw materials. The ultimate solutions to these challenges depend on the continuous innovations in photovoltaics technologies. Research collaborations among universities, large companies, small firms and national laboratories are essential to ensure that US is on the leading edge in this area. This workshop emphasizes on the technology transfer to bring the advance technologies from research level into viable products, and eventually to commercial market, thus realizing societal benefit and economic impact.
Photovoltaics manufacturing has surpassed the 10 GW/yr production threshold and is poised to accelerate as electricity production by PV reaches parity with conventional electric power generation technologies later this decade. It is expected that various forms of crystalline silicon will dominate the market for the foreseeable future. Significant opportunities remain to improve 1st generation solar cells, mainly through continued reduction of material requirements as well as additional improvements in module efficiency. Thin film CdTe has established itself as a major player in the global marketplace. Pending further improvements in efficiency, CdTe’s market share could evolve to anywhere between 5 – 25%. After decades of being the leading thin film technology, the prospects of amorphous silicon making a major contribution to the utility sector appear constrained by high manufacturing costs and low efficiency. CIGS has gained a foothold in PV manufacturing at ~100 MW/year, and the demonstrated potential in efficiency provides reason for guarded optimism. Although encouraging progress has been made, DSC and OPV are still limited at present by low efficiency and stability. Unless glass can be replaced, costs will remain critically high. If materials availability becomes a constraint at TW/year manufacturing levels it will likely favor silicon-based technologies, though understudied systems like CZTS deserve attention as their potential remains unknown. Fundamental challenges remain in 1st and 2nd generation PV technology, and additional investments in these areas are expected to have the most immediate impact in meeting the challenge of sustainable electricity production. Cross-cutting areas for investment Five challenges and topics that cut across the boundaries between the PV technologies discussed above are discussed as areas that warrant additional research investment. I. Development of National User Facilities for Photovoltaic Manufacturing Research All PV technologies discussed here have matured to a point that future advances will require simultaneous optimization of the many components that constitute a complete solar cell. An innovative process or new material may have tremendous intrinsic properties, but its value cannot be accurately assessed or fully exploited until integrated into a complete device structure. This poses a major barrier for both small business and university researchers alike, who most often cannot maintain the infrastructure of a full solar line. An excellent model that one might follow is the National Nanotechnology Initiative (NNI), which involves multiple government agencies and has invested $14 billion USD over the past decade into building infrastructure to promote and facilitate research, development, and technology transfer related to nanotechnology. We advocate that a similar investment be made in photovoltaic manufacturing science, perhaps organized with facilities focused on individual process technologies. Such facilities would dramatically accelerate the rate at which innovation can be harnessed to meet the terawatt challenge. II. Advanced photon management The importance of this topic is self-evident as this phrase was used in conjunction with the discussion of nearly every technology. Typically, advances and improvements in efficiency involve materials that are applied externally to the cell, allowing them to be developed independently without impacting cell designs that are highly optimized. Specific topics within this area, in order of increasing complexity are as follows. 1) Antireflection Coatings. 2) Increasing the Path Length through the Absorber. 3) Optical field enhancement. 4) Downshifting. 5) Downconversion. Often 6) Upconversion. III> Can glass be replaced? This is a simple but critical question. A detailed analysis of thin film manufacturing suggested that under optimal conditions manufacturing costs could be reduced to about $40 -50/m2 through economies of scale. It is not realistic to expect costs to be any lower for any technology that requires the use of glass and a transparent conducting oxide. A low cost, light-weight alternative that provides the same level of transparency, protection, and thermal stability would be nothing short of revolutionary. A positive answer to this question is essential if technologies such as OPV and DSC are to become cost-competitive for principal power generation. IV. The science of manufacturing With champion efficiencies nominally plateauing, the continued reductions in cost/Wp observed during the past decade has been due almost exclusively to advances in manufacturing technology. Manufacturing and process development is often overlooked as empirical knob turning, but there are many fundamental issues that have not been addressed. Development of competitive manufacturing techniques requires sophisticated modeling to understand how to maintain uniformity with respect to both space and time. V. Reliability science An overlooked issue is that the economics of PV are predicated on sufficient lifetimes, with targets traditionally of 20-30 years. Changes that improve efficiency are only beneficial if they last. There are limited tools beyond standard lifetime testing that can be used with any confidence to predict reliability. New advances in diagnostic tools to characterize structural and electronic changes as a device/module ages as well as models that accurately describe and predict behavior would accelerate progress in these areas.
