In short, Time Travel does have some storage fees imposed for maintaining historical data.
The way that these fees are calculated is by each day (24 hours) from each time the data has changed. By maintaining only the necessary information to restore the roots from a table that has been updated or deleted, Snowflake lessens the amount of storage that is needed for historical data. Essentially, the only storage usage that is calculated is the percentage of the table that changed.
In order to manage the storage fees with Time Travel, Snowflake has two table types (Temporary and Transient) that don’t have the same storage fees as Permanent Tables.These two table types’ maximum additional fees are limited to one day.
As a result, the maximum additional fees incurred for Time Travel by these types of tables is limited to 1 day.