Reshoring silicon photovoltaics manufacturing contributes to decarbonization and climate change mitigation
Abstract The globalized supply chain for crystalline silicon (c-Si) photovoltaic (PV) panels is increasingly fragile, as the now-mundane freight crisis and other geopolitical risks threaten to postpone major PV projects. Here, we study and report the results of climate change implications of reshoring solar panel manufacturing as a robust and resilient strategy to reduce reliance on foreign PV panel supplies. We project that if the U.S. could fully bring c-Si PV panel manufacturing back home by 2035, the estimated greenhouse gas emissions and energy consumption would be 30% and 13% lower, respectively, than having relied on global imports in 2020, as solar power emerges as a major renewable energy source. If the reshored manufacturing target is achieved by 2050, the climate change and energy impacts would be further reduced by 33% and 17%, compared to the 2020 level. The reshored manufacturing demonstrates significant progress in domestic competitiveness and toward decarbonization goals, and the positive reductions in climate change impacts align with the climate target. Introduction At the 2021 United Nations Climate Change Conference (COP 26) held in the U.K., attending countries agreed to sustain the goal of limiting global temperature rises to 1.5 degrees and to finalize the unfinished elements of the Paris Agreement 1 , 2 , 3 , 4 . The U.S. is ramping up its actions to create a carbon-free power sector by 2035 and to achieve “net-zero” greenhouse gas (GHG) emissions by 2050 5 . Facilitating this degree of climate change mitigation will require the accelerated deployment of fundamentally clean technologies, including sustainable solar photovoltaic (PV) technology, which marks the cleanest and cheapest form of electricity 6 . The growth of solar power has increased exponentially from small-scale applications to one of the mainstream sources of electricity, growing by more than 20% per year over the past six years 7 , 8 . The U.S. installed 14.9 GW AC (19.2 GW DC ) of PV in 2020, with PV accounting for approximately 40% of new electricity generation, up from just 4% in 2010 9 , 10 . By 2035, solar power is projected to support 40% of U.S. electricity demand, a tenfold increase over the solar output in 2021 11 . By 2050, solar could be nearly half of the electricity supply 11 . Solar power usage in the U.S. is also expected to reach 1067 TWh, 720% above the 130 TWh usage in 2020 8 . Following these projections, the market supply of PV technologies will be driven by energy policy goals and the aggressive pace of PV market demand. The energy policy goals and the soaring PV panel demand impose a great supply challenge for the PV industry to catch up with the growing needs in the coming decades. Most U.S. PV installations relied on the use of imported panels, mainly coming from Asia 12 . Safeguard tariffs were placed onto imported silicon solar modules and applied for four years starting from 2018, with the duties declining 5% each subsequent year to arrive at 15% in the fourth year 6 , as part of a trend of trade protectionism regarding PV manufacturing. Around 96% of the world’s PV production comes from crystalline silicon (c-Si), which includes single-crystalline silicon (sc-Si), ribbon silicon (r-Si), and multi-crystalline silicon (mc-Si), representing the most widely used semiconducting materials 11 , 13 , 14 . While U.S. dependence on imported c-Si PV modules is non-negligible, the market favorability for PV imports is declining, as revealed by a decreasing fraction of imported PV panels despite a decrease in the tariff on imported silicon solar cells in recent years 11 , 12 . Both supply instability and temporary trade restrictions due to geopolitical issues are the reasons behind the shift away of manufacturing from foreign supplies 15 . The effects of supply chain restructuring continue to propagate throughout the PV industry, as the overreliance on global trade structure emphasizes disruptions that jeopardize all countries involved 11 , 16 . While various countries locked their borders and international freighting took a nosedive in recent years due to the pandemic 17 , the demand for solar panels remains high due to elevated renewable electricity demand. Significant challenges have emerged in solar panel supply chains that face increasing risk from relying on external imports, which respond sensitively to any freight crisis or other potential disruptions 16 . Manufacturers want to move away from offshoring due to supply chain woes, geopolitical instability, freight cost, and many other considerations 18 . The production of solar panels […]
