Print-Assisted Photovoltaic Assembly (PAPA)

This proposal describes the development of an innovative method for the fabrication of thin-film photovoltaic panels. Print-Assisted Photovoltaic Assembly, or PAPA, uses advanced additive electronics manufacturing to print flexible paneling components around commercial off- the-shelf (COTS) solar cells. This builds a fully functional solar panel via an automated process. Currently, both state of the art (SOA) and advanced concept (e.g. thin-film) space solar panels are manufactured via the compilation of piece parts by hand. In contrast, PAPA automates a majority of this labor intensive process. The advantages are twofold: (i) Near Term: solar panel cost reduction and (ii) Long Term: capability for in-space solar array manufacturing. We propose through this CIF to develop the advantageous PAPA process. P.I. John Carr has an extensive background in photovoltaics and thin-film solar panels. He is joined by Co.I. Furman Thompson who has an extensive background in advanced manufacturing and additive electronics. Together, the investigators will fabricate thin-film solar panel assemblies using an additive print process and verify them to TRL4. Working prototypes which define the PAPA manufacturing process and a licensable patent are expected as end products.

PAPA is an innovative approach towards the advanced manufacturing of thin-film solar panels for small satellites and beyond. The use of thin-film based solar arrays for space applications has long been recognized as an advantageous power generation option. Thinner materials yield a mass savings, equating to lighter launch loads, larger arrays, and/or more payload allocation. Further, their mechanical flexibility lends itself well to stowage and deployment schemes, allowing for a vast improvement to both specific power (W/kg) as well as stowed power density (W/m3). A key application of thin-film space solar arrays is in the small satellite community. Their need for higher power generation coupled with the extreme mass and volume restrictions of the small satellite bus is driving the need for these lower mass, lower stowed volume, larger-scale deployed arrays. Beyond small spacecraft, the conformal nature of these flexible arrays enables them to be embedded in novel applications. For example, an inflatable habitat could have thin-film solar assemblies embedded in the outer walls, generating power without sacrificing volume, mass, or stowage and deployment schemes. These arrays could also be embedded into advanced spacesuits, providing trickle and emergency power to astronauts on surface missions. Extending further, thin-film arrays have the unique advantage of a direct path to a key goal of in-space manufacturing. This enables in-situ mission fabrication of these power generators, a highly advantageous tool for future space flight and habitation. To better manufacture these thin-film arrays and push towards the ultimate end goal of in- space thin-film solar panel manufacturing, PAPA is proposed herein.

PAPA uses additive manufacturing to fabricate flexible paneling components around COTS solar cells, automating the solar cell to solar panel process and taking the first steps towards a fully printed manufacturing process. Traditional SOA and advanced concept (e.g. thin-film) space solar arrays are currently manufactured by hand, compiling piece parts into an assembly. In contrast, PAPA replaces the labor process with an automated print. The advantages of this are twofold:

1. Short Term: Panel cost reduction for near term users. There is a community goal to bring the recurring cost of solar arrays – especially small satellite solar arrays – from >$1,000/Watt to <$400/Watt. Labor to assemble the solar cells into a panel is, itself, estimated to be between ~$250 and $450/Watt, let alone the solar cell, materials, and deployment mechanism costs. PAPA can reduce paneling labor costs of thin-film arrays to ~$25-$45/Watt while integrating COTS solar cells, better enabling the community to meet the <$400/Watt target. This cost reduction is highly desirable for NASA and other small satellite integrators.
2. Long Term: Capability for in-space solar array manufacturing. PAPA is the first step towards an entirely printed solar array and integrated power system. By adding a printed solar cell to the PAPA process, 100% automation of the assembly can be achieved. This would create the lowest mass, lowest volume, and lowest cost space solar panel to date. More importantly, this would enable in-space manufacturing of thin-film solar panels from raw materials and give NASA a highly advantageous tool for future capabilities to explore, work, and live in space. For example, surface habitation missions could print extra power sources on demand to incorporate additional mission scope, extend mission life, or replace a damaged panel.

Compared to by hand manufacturing, PAPA inverts the structure and replaces cell covering, cell interconnect, electrical routing, substrate bonding, and electrical grouting with an automated print process. This equates to ~80% of the labor process being replaced with additive manufacturing and the 10x reduction to the labor cost cited above. Only the cell laydown process remains via hand. However, this is a distinct advantage and intentional feature of the PAPA invention as it allows the process to work with COTS solar cells. And as cell advancements are made in the community, PAPA can continue to be used to panel them. 

The technical approach to develop PAPA and the expected final products can be found in the ‘Research and Development Plan’ section below. Opportunity after PAPA CIF: Looking forward towards the long term goal of in-space manufacturing, once the PAPA process is developed using COTS cells, NASA can move forward to pursue fully printed paneling. These panels may even be coupled with other additively manufactured power system components, such as thin film batteries, ultra capacitors, ribbon cabling and the like. Creating an integrated power system which can be manufactured in space – greatly altering our ability to explore, work, and live in space.

This is early/mid-stage (TRL 1) — the most realistic path in is NASA SBIR/STTR, which funds small businesses and research institutions to develop technology aligned with NASA's needs (equity-free, phased funding). Check whether a current SBIR/STTR solicitation topic overlaps with this project's technology area, or contact the project directly (above) to ask.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.