Can I initiate Find my iPhone from a windows PC?

There’s no magic available here that will solve this.

Not with a discharged device.

No Apple devices support receiving remote power and recharging at the distances involved here. Qi needs close contact.

You’re going to have to look for your iPhone the old-fashioned way. Manually.

Having gone through this with some other folks, order a lime green or fluorescent orange case. Something more visible. And maybe consider a Bluetooth tracker, though—again, having gone through similar before—the tracker itself is another thing that can (seemingly will?) get lost.

You can access it by logging into your account at https://icloud.com/find

However, as has already been noted, if the battery in your phone is dead, it won't do you much good.

Any internet connection that can open the iCloud.com web page.

If it doesn't have power it can't be remotely located.