Photovoltaic Technology based on Earth Abundant Materials - PVTEAM

To meet teraWatt photovoltaic (PV) capacity targets for 2050, solar modules will require:
1. Low manufacturing costs and carbon footprint as well as short energy payback time
2. To be incorporated into building-integrated systems
3. To be based on low-cost abundant elements
Current thin-film PV technologies based on copper indium gallium diselenide (CIGS) and cadmium telluride (CdTe) have already demonstrated their potential to deliver on the first two requirements. These technologies are currently manufactured at the GW scale, with approximately 10% of the PV market worldwide. However, low abundance, high costs and high toxicity of key elements (In, Ga and Cd) present in active layers are set to severely limit the expansion of this technology in the next decades. Consequently, material substitution and the development of scalable (non-vacuum) processing technologies represent an extraordinary opportunity for the UK to grab an important share of the global photovoltaic market.

The aim of PVTEAM is to lay the foundations of sustainable thin-film PV technology based on Earth abundant materials and scalable manufacturing processes. This will be achieved by developing processes and production technologies for materials and material systems to a level they can be taken up by manufacturing industries. This programme covers material specifications and performance, integration into cells and mini-modules as well as developing the technologies required for scale up. PVTEAM will specify a carefully selected range of binary, ternary and quaternary chalcogenides and oxides as substitutes to proven commercial materials. Using a multi-level screening approach, we will incorporate the best performing candidates into industrial processes based on "substrate" and "superstrate" configurations.

The consortium involves five universities with state-of-the-art infrastructure for material development and characterisation as well as for device fabrication, testing and integration into PV modules. Material processing will be based on facilities available at the Sustainable Product Engineering Centre (SPECIFIC), which will be in charge of designing scale-up strategies and preparing techno-economic assessment. The PVTEAM industrial partners, Tata Steel, Pilkington NSG and Johnson Matthey, have a worldwide footprint on materials for the construction, coating and chemical industries. The consortium also includes SMEs, M-Solve and Semimetrics, which will provide means for the exploitation of new PVTEAM technologies in module fabrication and metrology.

1. Building UK Photovoltaic Capacity
The long-term aim of PVTEAM is to lay the foundations of sustainable thin-film PV technology based on Earth abundant materials and scalable solution processing. Our workprogramme perfectly aligns with the principal target of SPECIFIC IKC, i.e. 'Buildings as Power-stations'. The PVTEAM vision focuses on the accelerated development of scalable printed thin-film PV devices on flexible metal substrates. Building integration of PV offers a number of advantages over the application of conventional roofing panels particularly when deployed in large buildings such as supermarkets. To illustrate the potential, Tata in the UK manufacture 100 million m2 per annum of building and roofing material for such buildings with an average supermarket having a roof area of up to 20,000 m2 equivalent to 2MWp. A 10% conversion of Tata capacity to PV products by 2020 has the capacity to deliver 1GWp per annum equating to an annual 6MT CO2 saving by 2025.

2. Wealth Creation and Employment
The partnership of academic institutions in PVTEAM with the main industrial partners via SPECIFIC IKC is key to ensure impact to the UK PV manufacturing industry. One of the tools for delivering such impact is the PV Accelerator pilot line based in the Shotton Steel works in North Wales, comprising a team of over 30 scientists and engineers supported by Tata. Implementation of thin-film PV technology at this scale requires:
a) Substitution of costly and toxic elements such as In, Ga, Te and Cd present in conventional thin-film PV
b) Scalable solution processing of active layers.
These two aspects lie at the heart of the PVTEAM vision. There is clearly a tremendous export potential for such technology given its environmental attractiveness and the global reach of a manufacturer like Tata.

Direct job creation in automated manufacturing is likely to be around 120 full time staff per manufacturing line with associated technical and research support in industry adding around 30 more. This number is only a small fraction of the total job creation involving suppliers and customers. As a guide to the impact, existing coil coating lines support six additional jobs per manufacturing line worker, so that a 4 million square metre production line would support around 1000 UK supply chain jobs.

3. Removing barriers to industrial exploitation and developing the value chain
By implementing stringent reliability tests and fully accredited measurements, the technology developed by PVTEAM is expected to conform to standards of reliability for the PV industry. This will enable to identify and remove non-technical barriers which could hinder the scale-up and exploitation of modules based on Earth abundant materials. These crucial issues in the path to scale-up will be part of the generic approach to material substitution in PV technologies to be developed by PVTEAM.

On the supply side, PVTEAM partners Johnson Matthey, M-Solve and Semimetrics will be uniquely positioned for exploiting developments on precursors for active layers, module integration (interconnects) and in-line metrology/testing of semiconductor materials, respectively.

4. People
PVTEAM has developed a holistic view towards sustainable PV which is set to deliver highly skilled scientists and engineers. In addition to the five PDRA directly supported by the EPSRC within the framework of this project, at least five PhD and EngD students will be joining the consortium from the various academic partners. The strategic partnerships with two Centres for Doctoral Training (Bristol Centre for Functional Nanomaterials and Bath Centre for Sustainable Chemical Technologies) as well as the Centre for Engineering Doctorate at Swansea will allow disseminating the PVTEAM activities to future research leaders and technologists.