Look up SSE SET acronym and find out about the things which are important to Sse. This is on the website. Do your research, learn about the company and the different things they provide apart from gas and electric. You might be given a list of things to place in order of importance. Make sure you listen and show you are great at working as a team and as an individual. It's also important to prove you are good with meeting/beating targets.
Answered - Accounts Payable Administrator (Former Employee) - Motherwell, North Lanarkshire
Definitely read there home page and the blog from the CEO
Answered - Customer manager/advisor (Former Employee) - Perth, Perth and Kinross