This was originally posed to me this summer as a group of Marvel's smartest heroes gathered together to discuss the latest of Tony Stark's inventions, a mega project which dwarfs those conceived by real people (I am looking at you Atlantropa):

The formula for the surface area of a hexagon (approximate) is this: 2.598076211t^2 where t is the length of the side. This makes them 41.6 square meters. It would appear that the sides are about 4 meters long based off of how tall the character likely are and how they appear next to the panels. Here is the formula for the surface area of a sphere 4 pi r^2. This would help to know where they are building the Dyson sphere. If it is at Pluto then 2% of that to be operational would be 8,763,182,503,410,888,000 square kilometers (thats almost 9 quintillion). Lets say it is a lot closer, just past Mars? Well that is a more reasonable 13,046,928,592,000,000 square kilometers (like I said more reasonable only 13 quadrillion). So in a square kilometer there are one million square meters (because one kilometer = one thousand meters, so to square both sides makes one million squares). Seeing as a panel is 41.6 square meters this means that 25,000 of them would make one million square meters, or about 24,000 of them. So then, in the first case that would mean 210,316,380,081,861,300,000,000 (210 sextillion) panels. The Mars one would need 313,126,286,208,000,000,000 (313 quintillion). I just pulled this number off of the internet and I think it is exaggerated but say there are 100,000 blades of grass per square meter. That makes for easy division though as there would be 100 trillion per square kilometer. In the first case of the Pluto Dyson Sphere and if one blade of grass represents one panel that would mean 210,316,380 square kilometers, which would mean hand planting that many blades of grass on over half of the planet Earth (and over half of planet Earth is covered by water, so essentially it would mean cover every piece of land on Earth with one blade of grass.