When a newly established English vineyard began receiving its first electricity bills, the finance team noticed something alarming. The daily standing charge alone was costing hundreds of pounds, even before significant electricity usage was factored in.
Although the supplier confirmed the charges matched the signed contract, the scale of the fixed cost raised serious concerns. What followed uncovered a technical classification error that had embedded a six-figure annual overcharge into the agreement.
The contract pricing later proved to contain an annual structural overcharge of approximately £143k/yr
The Client Situation
An English vineyard and wine producer had recently connected a new electricity supply for its winery operations. Shortly after energisation, the business found:
With no prior experience of high-voltage commercial energy supplies, the Finance Director had no reliable comparison point but the numbers didn’t feel right.
The business wondered whether occasional high-demand periods (such as harvest or bottling) might require higher infrastructure capacity, potentially justifying the cost.
Why We Suspected a Technical Error
In commercial energy, unusually high standing charges often point to one of several technical issues:
Because this was a brand-new supply, the risk of setup errors was significantly higher.
Errors like this are far more common than most businesses realise, particularly with new commercial connections where suppliers rely on initial setup requests rather than the final installed infrastructure.
As such, we verified the site’s official technical supply record directly with the Distribution Network Operator (DNO), UK Power Networks.
The Critical Discovery
UK Power Networks confirmed:
However, EDF created the contract:
EDF later acknowledged the HV classification originated from the original new-connection request.
Why Voltage Classification Matters So Much
Voltage level is one of the biggest drivers of fixed electricity costs. High Voltage supplies:
Low Voltage commercial sites operate using standard distribution networks and should pay dramatically lower fixed costs.
Because the winery had been billed as HV, the standing charge was massively inflated.
The Financial Impact
Original standing charge: 43,217p/day (~£432/day)
Correct LV standing charge: 4,101p per day (~£41/day)
This meant the contract contained an annual structural overcharge of approximately £143k per year (£142,775 to be precise).
Between June 2024 and March 2025 alone, the business had already overpaid £109k
Supplier Resolution
Once the DNO confirmation was presented, EDF accepted that the supply had been misclassified.
They initiated an internal replacement-contract process to:
On 30 July 2025, EDF confirmed: “A refund of £109,421.60 has been processed…”
The client confirmed receipt of the refund.
Key Lessons for Businesses
This case highlights risks that commercial energy customers may be unaware of.
Final Outcome
✔ Voltage classification corrected
✔ Standing charge reduced by roughly 90%
✔ Over £109k refunded
✔ Future overcharge of £143k/yr eliminated
Final Thought
Most businesses focus heavily on negotiating cheaper unit rates when reviewing energy contracts.
But as this case shows, sometimes the biggest financial risk lies not in the price per kWh but in whether the technical supply data behind the contract is correct at all.
For any business operating a new commercial connection, unusually high standing charges, or unfamiliar infrastructure classifications, a technical supply audit can uncover errors that would otherwise remain hidden for years.
