The math means a lot because the Silver State South project would be built at one of the narrowest points of the Ivanpah Valley, which serves as an important habitat linkage for the threatened desert tortoise. A bigger solar facility equates to a narrower (or non-existent) habitat linkage. A weak or non-existent habitat linkage means this species may lose genetic diversity and resilience needed to face continuing threats to its recovery, including disease, habitat loss, and climate change.
Although the draft supplemental EIS does not consider a 250 megawatt alternative, I figured I would play with the footprint of the 350MW alternative on Google Earth to see what a notional 250MW layout might look like, and how much desert wildlands could be saved. I calculated the number of acres per megawatt by dividing the total acreage for the BLM's preferred layout -- including the permanent and "temporary" disturbance for the drainage basins -- by 350 MW. That leaves us with roughly 9.26 acres per megawatt, including drainage basins. So a 250 MW alternative could be about 2,317 acres -- possibly a bit more, or a bit less depending on how an altered layout changes the drainage basin requirement. But shaving that acreage off of the eastern edge, which obstructs the habitat linkage, could give us nearly a mile wide corridor. That is double the corridor allowed by the proposed 350MW alternative.