Recent work found that renewable energy could supply 80% of electricity demand in the contiguous United States in 2050 at the hourly level. This paper explores some of the implications of achieving such high levels of renewable electricity for supply chains and the environment in scenarios with renewable supply up to such levels. Expanding the renewable electricity supply at this scale by 2050 implies annual capacity additions of roughly 20 gigawatts per year (GW/year) over the next decade, rising to roughly 40 GW/year from 2040 to 2050. Given total 2012 renewable electricity capacity additions of slightly more than 16 GW, this suggests moderate growth of the related supply chains, averaging overall roughly 4% annual growth to 2040. Transitioning to high renewable electricity supply would lead to significant reductions in greenhouse gas emissions and water use, with only modest land-use implications. While renewable energy expansion implies moderate growth of the renewable electricity supply chains, no insurmountable long-term constraints to renewable electricity technology manufacturing capacity or materials supply are identified.