User
The User model corresponds to a utility login. If your user has multiple utility logins, say a PG&E login and an SCE login, they must go through the Connect flow multiple times. Each of these utility logins will be associated with a Pelm User.
Account
The Account model corresponds to an account under a utility login. There is typically a one-to-one mapping of Account to property. If a user has a residential home, a rental home, and a vacation home, these would correspond to three different Pelm Account objects.
Interval data is associated with an Account.
Common scenarios
Bob owns three houses in the Bay Area. PG&E serves gas and electricity for each of his houses. Bob would need to go through the Connect flow once. One Pelm User will be created for Bob and it will be associated with three Account objects.
Alice lives in Southern California. SCE provides her electricity and SoCal Gas provides her gas. Alice would need to go through the Connect flow twice. Two different Pelm User objects will be created for Alice. One will be associated with an SCE Account object and the other will be associated with a SoCal Gas Account object.