system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: In England all energy providers provide energy from the same grid, how comes they are all able to sell the exact same product at differing prices? And why is there competition between them?
gpt
They basically just keep track of how much energy they provided to the communal grid, and how much their customers drew from the communal grid.  They can produce it at a certain price, and prove their customers drew that power out the other side, so it doesn't really matter where the specific electrons came from as long as they provided enough for their customers' use.  Make sense?