In Animal Farm, what idea did Snowball have to improve conditions on the farm?

Snowball's major idea for improving the conditions on Animal Farm is to build a windmill.  He proposes this idea in Chapter V.

Snowball argues that building a windmill will improve the lives of all the animals.  He says that with the windmill they will no longer have to work any more than 3 days per week.  He says that the windmill will generate electricity that will allow the animals to have warm stalls.

Napoleon is totally opposed to the idea of having a windmill.  When Snowball speaks in favor of the idea, Napoleon has him chased from the farm.