ENERGY · HOW ENERGY MARKETS WORK UK
How Energy Markets Actually Work
A detailed guide to how UK gas and electricity markets operate, from generation and wholesale trading to suppliers, networks and regulation.
Quick summary
- Energy is traded in wholesale markets before reaching suppliers
- Gas often sets electricity prices in the UK
- Suppliers hedge energy months or years ahead
- Network costs are regulated and form part of your bill
- Global events heavily influence UK prices
- Ofgem regulates suppliers and the Energy Price Cap
For information only
When energy prices rise, headlines often say “wholesale prices increased” or “gas markets surged.” But what does that actually mean? Behind every unit of electricity or gas supplied to your home is a layered system involving: • Power stations and gas producers • International commodity markets • Traders and risk managers • Transmission and distribution networks • Energy suppliers • Regulators Your bill reflects the combined cost of all of these components. Understanding how the energy market works helps explain: • Why gas prices affect electricity bills • Why suppliers failed in 2021–22 • Why the Energy Price Cap exists • Why prices can rise even if renewable generation increases • Why fixed tariffs sometimes disappear This guide explains the full system in clear, practical terms. This is general information about UK energy markets and regulation. It is not investment or financial advice.
The Energy Supply Chain — From Source to Socket
Energy reaches your home through several stages:
1. Generation or extraction
2. Wholesale trading
3. Transmission and distribution
4. Retail supply and billing
Electricity generation sources include:
- Natural gas
- Wind
- Solar
- Nuclear
- Hydro
- Biomass
Gas is:
- Extracted domestically (North Sea)
- Imported via pipelines (e.g., Norway)
- Delivered as liquefied natural gas (LNG) via ships
Once produced, energy is traded in wholesale markets before being delivered via regulated networks to suppliers, who then bill households.
Your bill reflects all these layers.
Why Gas Prices Influence Electricity Prices
One of the most misunderstood aspects of UK energy pricing is the “marginal pricing” system.
Electricity is generated from multiple sources simultaneously. The price of electricity in wholesale markets is typically set by the most expensive generator needed to meet demand at that time — often gas-fired power stations.
This means:
- Even if wind or nuclear produce cheaper electricity
- If gas is needed to meet total demand
- Gas sets the clearing price
During periods of high gas prices (such as 2021–22), electricity wholesale prices rise sharply — even if renewable output is high.
This is not because electricity “is made from gas,” but because gas often sets the marginal price in the market structure.
Wholesale Energy Markets Explained
Suppliers do not buy energy daily at spot prices for all customer usage. Instead, they use hedging strategies.
Wholesale markets include:
- Day-ahead markets
- Forward markets (months ahead)
- Futures contracts (years ahead)
Suppliers typically:
- Buy energy in advance
- Lock in prices
- Spread purchasing over time
This reduces exposure to price spikes — but only if done prudently.
In 2021–22, many smaller suppliers had not hedged sufficiently. When wholesale gas prices surged, they could not absorb the costs and collapsed.
Why Supplier Failures Happened in 2021–22
More than 30 UK suppliers failed during the energy crisis.
Key causes included:
- Inadequate hedging
- Rapid expansion without capital buffers
- Underpricing tariffs
- High exposure to wholesale spot markets
When gas prices rose dramatically due to global supply shocks, these suppliers:
- Faced energy purchasing costs above what customers were paying
- Could not pass costs on quickly due to the Energy Price Cap
- Became insolvent
Customers were transferred under Ofgem’s Supplier of Last Resort (SoLR) process.
This episode exposed structural weaknesses in supplier risk management.
Network Costs — The Invisible Infrastructure
After energy is generated, it must travel through:
- High-voltage transmission networks
- Local distribution networks
- Gas pipelines
These networks are natural monopolies and are regulated by Ofgem.
Network charges fund:
- Maintenance
- Infrastructure upgrades
- Grid balancing
- Smart grid technology
- Reinforcement for renewables
These charges form a portion of every household bill and are not directly linked to wholesale market volatility.
The Role of Energy Suppliers
Suppliers are the retail-facing companies.
They:
- Buy energy in wholesale markets
- Manage risk
- Bill customers
- Provide customer service
- Comply with regulatory obligations
They do not generate most energy themselves (with some exceptions).
Suppliers make margin between:
- Wholesale procurement cost
- Network and policy charges
- Operating costs
- Retail price charged to customers
Margins in domestic supply are often relatively thin under price cap regulation.
The Energy Price Cap
The Energy Price Cap is set by Ofgem and limits the maximum unit rate and standing charge suppliers can charge customers on standard variable tariffs.
It is:
- Updated quarterly
- Based on estimated wholesale costs
- Inclusive of network and policy charges
- Not a cap on total bill
If wholesale prices rise sharply, the cap increases. If they fall, it decreases.
It is designed to prevent excessive pricing — not eliminate volatility.
Global Factors That Influence UK Energy Prices
The UK is not isolated.
Gas prices depend on:
- Global LNG demand
- European storage levels
- Geopolitical conflict
- Weather
- Supply disruptions
For example:
- Reduced Russian gas flows into Europe in 2022
- Increased Asian LNG demand
- Limited UK storage capacity
All contributed to price spikes.
Even though the UK produces some gas domestically, it is priced at international market rates.
Renewable Growth — Why Prices Still Fluctuate
Renewable generation has increased significantly in the UK.
However:
- Renewables do not eliminate need for flexible generation
- Gas is still used to balance the grid
- Storage infrastructure is limited
- Market pricing still follows marginal system
Until grid-scale storage and flexible demand expand significantly, wholesale electricity pricing remains influenced by gas.
How This Affects Households
For households, this complex system translates into:
- Unit rates per kWh
- Standing charges
- Fixed vs variable tariff decisions
Understanding market structure helps explain:
- Why fixed deals disappear during volatility
- Why green tariffs still track wholesale movements
- Why price cap rises follow global events
It also explains why supplier financial stability matters.
Key takeaways
- Energy markets are layered and global
- Gas frequently sets electricity prices
- Suppliers hedge in advance to manage risk
- Network costs are regulated and stable
- Global events directly affect UK bills
- The price cap moderates but does not eliminate volatility
Why does gas price affect electricity price?
Because gas often sets the marginal price in the wholesale electricity market.
Do suppliers make large profits when prices rise?
Not necessarily. Retail margins are regulated and often thin under the price cap.
Why did suppliers fail in 2021–22?
Many had inadequate hedging and could not absorb rapid wholesale price increases.
Will renewables stop price volatility?
Over time, greater renewable penetration and storage may reduce volatility, but current pricing systems still link electricity to gas markets.
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