Please follow the steps below to get Google Photo Album URL from picasaweb.
Suppose You have Google photo albums saved in Google photos. Now Go to https://picasaweb.google.com/ , If you are logged in in google, then you will also automatically login to Picasaweb otherwise you have to login to Picasaweb with your google account.
After login into picasaweb, your google photos and photo albums will automatically display as thumbnails (See Image -1). Click on any photo album to get its URL. After opening the album you will find the photos of the album on the left site and you will find your profile and album details on the right side. On the right side you can define the album, wheather it is is private or public. This is called visibility on web. You have to make it Public. (See Image -2).
Now get the link. Open an album on picasaweb, make sure it is Publicly visible. Left side of the album you will find the photos of the album and at the right side you will find the album details. In the album details ther is a term Called "RSS". Right Click on RSS and copy the Link Address. This link is the google album Link using Picasaweb. See Image -3