Where can I get alot of Wind Shard?

[Sida]

Apart from the obvious answer, Market Board, you could send miner or botanist retainer gather them. The better their gathering stat is, the larger amount they will haul, so even if the shards are level 1 gather for them, leveling them and then kitting them with better gear helps to get larger hauls.

My miner/botanist retainers are roughly on level 30 and their gathering stat is currently in about 150 and they bring 60 shards in 40 minutes. The time decreases from the initial 1 hour when the level difference between your retainer level and the level of the item they gather grows.