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Wholesale Energy Cost
Key takeaways
Wholesale energy cost is what suppliers pay to buy electricity or gas before selling it on to customers.
Ofgem describes wholesale purchasing costs as the largest component of a customer bill.
Wholesale prices move often, which is why fixed contracts and flexible/index-linked contracts behave very differently.
What is the wholesale energy cost?
Wholesale energy costs are the costs suppliers incur when buying gas or electricity in the wholesale market to supply customers.
Ofgem’s wholesale market indicators explain that suppliers typically buy energy using wholesale forward contracts, and that wholesale prices can vary significantly.
NESO also summarises wholesale markets as the buying and selling of electricity between generators and suppliers.
How suppliers buy energy (simple version)
Most suppliers don’t buy everything “on the day”.
They typically buy in different timeframes to manage risk, for example:
- Forward purchasing (locking in prices ahead of time)
- Day-ahead / near-term buying (fine-tuning volumes)
- Balancing (real-time adjustments to match supply and demand)
The exact approach varies, but the purpose is the same: reduce the risk of being exposed to sudden price spikes.
Why wholesale cost matters for your quote
Wholesale cost strongly influences:
- your unit rate
- the supplier’s risk premium (what they add for uncertainty)
- whether “fixed” pricing looks attractive vs flexible pricing
As a rough rule:
- Fixed rate contracts give budget stability (supplier takes more price risk).
- Flexible / index-linked arrangements can track markets more closely (you take more price risk).
