You will be billed every quarter for all the gas and electricity you have used in the business.
Until you have been trading for a few months you will not know exactly how much energy the business will use. Your energy supplier may be able to give you some guidance, based on the size of your premises and the nature of any equipment you will be using (for example, photocopiers). You can adjust the figures once you have been in the premises for a few months.
It's worth shopping around the different energy companies to get the best deal for your business, particularly if you're going to be a heavy energy user.
You're quite likely to have fairly large premises, such as a warehouse. Buildings like this are often draughty and poorly insulated, so you'll want to make sure your heating bills aren't excessive. Think about which bits of your premises need to be heated and which don't. Think too about lighting - choosing an energy-efficient option can save you a considerable amount of money over time.