In addition to unit charge and standing charge, you will notice over charges such as FiTs (feed-in-tariffs) CCL (climate change Levy) and Renewables Obligation (RO) on your bill. These additional charges are Levies and taxes relating to the environment and social obligations. a half hourly meter will also have additional operating (MOP) charges and other costs associated with the network and supplier operating costs. These apply to all contracts (even 100% renewable), sometimes they are factored in to the unit rates, other times they are listed separately – it’s worth checking which applies, as it may appear you have a great deal when you could do better if the additional charges are calculated separately to your unit rate.