Geographical Dependence of Open Hardware Optimization: Case Study of Solar Photovoltaic Racking

Abstract

Open-source technological development is well-known for rapid innovation and providing opportunities to reduce costs and thus increase accessibility for a wide range of products. This is done through distributed manufacturing, in which products are produced close to end users. There is anecdotal evidence that these opportunities are heavily geographically dependent, with some locations unable to acquire components to build open hardware at accessible prices because of trade restrictions, tariffs, taxes, or market availability. Supply chain disruptions during the COVID-19 pandemic exacerbated this and forced designers to pivot towards a la carte-style design frameworks for critical system components. To further develop this phenomenon, a case study of free and open-source solar photovoltaic (PV) racking systems is provided. Two similar open-source designs made from different materials are compared in terms of capital costs for their detailed bill of materials throughout ten locations in North, Central and South America. The differences in economic optimization showed that the costs of wood-based racks were superior in North America and in some South American countries, while metal was less costly in Central and South America. The results make it clear that open hardware designs would be best to allow for local optimization based on material availability in all designs.

Ballast-Supported Foundation Designs for Low-Cost Open-Source Solar Photovoltaic Racking

“…Furthermore, the final costs of these systems are subject to change based on the cost of lumber at the time of purchase and where the material is being purchased [76]. A sensitivity analysis is provided on both commodity wood pricing and location to provide a range of final costs and costs per W of each system.…”

“…In the extreme case, such as Cape Race, Newfoundland, where the wind load is more than double that of typical urban cities, this system becomes challenging. The applicability of these systems worldwide [76], much like in Canada, is dependent on the calculated wind load, and the individual's decision in deeming if the build is feasible based on the cost of rocks associated with this wind speed. As shown in the Appendices, the distance to the center of the modules, d, has a direct correlation to increasing the price.…”

“…Open-source wood-based PV racks provide substantial savings in Canada, but the benefit in building a system in other countries depends on the lumber availability in each region [76]. Previous work investigating the economics of racking in the Americas has shown that wood-based PV racking was economically advantageous in all of North America (Canada, U.S., and Mexico) as well as countries such as Argentina, however, in other South American countries, metal racking was advantageous [76]. Thus, it is very clear that this approach is highly dependent on the price differential of building materials in different countries.…”

“…other South American countries, metal racking was advantageous [76]. Thus, it is very clear that this approach is highly dependent on the price differential of building materials in different countries.…”

Solar photovoltaic wood racking mechanical design for trellis-based agrivoltaics

“…Wood has already been shown to be a cost-effective racking material for fixed tilt [20], variable tilt [27], vertical PV [28] and awning designs [86]. Previous work has shown that the economics of wood vs aluminum racks varies widely by geography [87], but it is superior in most of North America.…”