The wholesale electricity (power generation) cost only makes up about 20% of the total cost to supply electricity to residential customers. The remaining 80% of the cost to supply includes network costs (building and maintaining poles and wires), capacity costs (maintaining enough generators to meet peak demand) and other costs such as those associated with renewable schemes and retail. These costs contribute to the reliability of the grid, so that power is available whenever you need it.
When we purchase electricity from our customers we don’t receive any of the other services such as network, capacity and retail services that are needed to supply electricity to another home. Therefore, the DEBS is closer to the wholesale electricity cost rather than the total electricity supply cost. In some towns this wholesale cost is very high, and therefore higher buyback rates apply.