No. When you’ve chosen a new deal, your new supplier will handle the switching process. They’ll contact you to let you know what date you’ll be transferred over, and they’ll contact you around the switching date to ask for a meter reading. They’ll pass this on to your old supplier so they can send you a final bill. You don’t need to contact your old supplier, as the new supplier will handle everything for you.
Wind and solar power are non-dispatchable. Such power is normally sold before any other bids, at a pre-determined rate for each supplier. Any excess is sold to another grid operator, or stored, using pumped-storage hydroelectricity, or in the worst case, curtailed. Curtailment could potentially significantly impact solar power’s economic and environmental benefits at greater PV penetration levels. Allocation is done by bidding.
Unlike with long-term plans, monthly, variable rate (no-contract) plans have no cancellation fees. You won’t have to pay a penalty if you decide to take your business elsewhere because you found a better deal. Plus, you won’t be left paying more than you should if the market rate for energy trends down. However, if the market prices rise, you’ll have to pay more than those who are in-contract.