This map traces every cost that ends up on a GB electricity bill, following the physical journey of electricity from where it is made to where it is used.
1.Generation
Electricity starts with generators — gas, wind, solar, nuclear, biomass and imports. Suppliers buy this output in the wholesale market, which is the single largest cost on most bills. Layered on top of generation are the policy and generation levies that fund the shift to low-carbon power: the Renewables Obligation, Contracts for Difference, the Feed-in Tariff legacy scheme, and the Nuclear Regulated Asset Base.
2.Transmission and the system operator
Electricity then moves across the high-voltage transmission grid, operated and balanced in real time by NESO, the National Energy System Operator. The cost of using and balancing this grid reaches bills through network and system charges — Transmission Network Use of System charges, Balancing Services Use of System charges, and the cost of energy physically lost as heat on the transmission wires.
3.Distribution
At Grid Supply Points the electricity steps down onto the regional distribution networks that carry it the last miles to homes and businesses. This adds Distribution Use of System charges, distribution losses, and a small cross-subsidy — Assistance for Areas with High Electricity Distribution Costs — that keeps charges affordable in the remote North of Scotland.
4.The supplier
Almost every cost above is collected by the retail supplier and passed through to the customer. The supplier also carries its own costs: buying wholesale energy ahead of time (hedging), settling imbalances, running the business, funding bad debt, and earning a modest margin.
5.Consumption
Finally the bill lands with the customer — a home, an SME, or an industrial site. Every bubble on this map is one component of what they pay.
Sitting above all of this is the regulatory and policy framework: the Department for Energy Security and Net Zero sets policy and law, and Ofgem regulates the market within it. They do not appear as a line on the bill, but they design and govern almost every cost shown here.