Photovoltaics Module and System Electrical Connections (CABLE)

f. Photovoltaics Module and System Electrical Connections (CABLE) This subtopic solicits proposals for innovative technologies and approaches that improve the quality and performance of photovoltaic (PV) electrical connections at the cell, module, or system level while reducing their cost. Metal conductors extract the charges that light generates in solar cells so they can flow to the rest of the solar array. These electrical conductors include the metal contacts on the solar cell, wiring, and connectors. This subtopic seeks proposals for the application of new conductive materials and related technologies to advance the state of the art in two areas: cell and module metal contacts and interconnects and PV system electrical connections. Applicants must clearly indicate which of the two areas of interest being proposed. 1. Cell and module metal contacts and interconnects There are strict requirements for making high-performance contacts and interconnects. Improvements in contacts are needed to increase the conductivity and durability while reducing their total cost of processing and raising the overall module performance. Applying the contact to the solar cell must: (1) not introduce too many recombination centers at the interface of the metal and the absorber material, because it would reduce the power output, (2) form an energetically favorable path at the interface for charges to move from the absorber material to the metal, and (3) be conductive enough to carry charges out of the cell without appreciable loss due to series resistance or shadowing. These technical requirements must all be met while maintaining low cost, reliability, durability over decades, and compatibility with the packaging materials and existing manufacturing processes. Meeting these requirements through the application of new materials has the potential to meet these requirements. A third of cell fabrication costs are attributed to metal contacts. Metal contact and interconnect costs are between 10% and 30% of the total module cost owing to the materials and processing costs. Applications to this area should propose the development of new cell and module metallization materials and processes. Applicants are expected to include objectives and milestones targeting a recombination current density (Jo) of the metallization contact of less than 10 fA/cm2, contact shading < 3% of active area, a cell fill factor of greater than 80%, and improved durability under chemical, thermal, and mechanical stresses that a module will experience in the field. The total cost for the metal contact materials and manufacturing step should be less than half of current costs, and projects must show that final mini-module test structures have better energy yield than a comparable baseline that uses state-of-the-art technology. 2. PV system electrical connections Innovations in wire management and cable attachment present an opportunity to extend system durability well beyond the traditional 25-30-year PV plant life. EERE's goal is to extend the operational life of PV systems to 50 years. Critical interfaces and conductors must be capable of maintaining low-resistance electrical pathways despite thermal cycling, moisture ingress, mechanical loading, and other environmental challenges. At the utility scale, designs that increase the mechanical robustness of cabling interfaces, such as the attachment point to a tracker or designs that increase the installation speed of a PV plant, may result in lower levelized cost of electricity (LCOE) through lower operation and maintenance (O&M) and capital expenditures (CapEx) costs. Applications in this area must demonstrate improved durability under accelerated life testing commensurate with a 50-year system lifetime with equivalent or improved electrical conductivity. Novel solutions for integrated wire management, such as cabling embedded in module framing or racking, may improve resistance to animal and environmental damage, thus avoiding expensive repair and replacement costs over the life of the system. The goal of this subtopic is to double the durability of PV systems or residential cabling and cabling attachments while reducing both installation time and bill-of-materials cost by 10%. Applicants must demonstrate the improvement by relevant component-level testing, using state-of-the-art, commercially available products for comparison. Please refer to Topic 16 (SETO) for other opportunities related to solar energy technologies other than module and system electrical connections. Questions Contact: solar.sbir@ee.doe.gov