In Chapter Five of Animal Farm, Snowball surveys the farmland and develops an idea to build a windmill. When he announces this idea to the others, his dreams for this project become clear. He talks about this "fantastic" machine, for example, and says that it can do their work for them while they "graze in fields" all day. In fact, after looking over the plans, Snowball declares that the windmill can reduce the animals' working week from six days to three. This is a significant reduction which makes his plans for the windmill very popular on the farm.
In addition to its labour-saving abilities, Snowball wants to use the windmill to generate electricity. This will enable the introduction of more labour-saving devices, like the plough, as well as the ability to provide heating and lighting to individual stalls in the barn.
It is this dream, however, which brings Snowball into conflict with Napoleon and which ultimately brings about his expulsion from the farm.