The rise in solar panel prices after tariffs meant that companies that had stockpiled panels couldn't always offload them. And it contributed to many of the already-purchased solar panels languishing in storage. Building a solar farm generally takes three to four years, and plenty of hurdles can arise along the way. “Some of the developers might not find the proper land to install panels and some of them might not be approved to connect to the power grid,” Chang says. Many solar farms that had been planned were never built, leaving the unused panels stuck in the warehouses.