Green New Deal... While the outline that was made available is very light on details there are a number of references that are sighted in the outline. The key one for costs and capability for energy generation and the grid is the Stanford paper by Jacobson, et. al. At 107 pages with probably 20 of that as math, it will take some time to read in detail. One thing that pops to mind quickly in the paper is that the authors only took the foundation area of wind turbines as land use, so they show a very small amount of land used or wind turbines. The second thing that pops out is that they used absolutely the best possible solar capacity factor - not the US average, or even a state by state. The third thing that is clear is they are working to an average power production for the whole year and not taking into account seasonal or regional differences. I suspect I will end up taking several weekend days to go through it in detail, but based on just those few factors, I would guess (and it is only a guess) that the report understates the impact in both cost and land use for 100% renewables system.