"In the event of a power cut, (SP Energy's) teams work around the clock to restore your electricity as quickly as possible. (They) appreciate for some customers this may be particularly distressing and that’s why (they) offer extra support to customers who feel they need (their) help." - which energy supplier you use is not relevant - SP Energy provide support for ALL energy customers.
You can join their Priority Services Register if you:
Are over the age of 60
Have a special communication need
Depend on electricity for home or medical care
Have a child under 5 years of age
Have chronic illness, or
you just feel you need a little extra help.
You can also register with them if you feel you need support for a short period of time e.g. if you're recovering from an operation, if you are pregnant, or if you are recently bereaved.
Being on their register won't necessarily mean they can restore your power more quickly, however they will try to proactively contact you if they know of a problem in your area.