Net Zero, Electricity and the Changing Grid
A guide to what the dashboard's electricity data can tell us about the energy transition, and what it cannot.
Generation mix is not the same as total energy use
The generation mix shows the sources producing electricity during a given period, such as wind, solar, gas, nuclear and biomass. Great Britain also imports and exports electricity through interconnectors, and storage can shift electricity between periods. Imports are shown as transfers; the generation mix in the exporting country is not identified in these figures.
This dashboard covers the electricity system. It does not show all energy consumed for transport, heating or industrial processes, much of which may still come directly from fuels rather than electricity. The mix also changes through the day as weather, demand, plant availability and network constraints change.
How electrification may change the mix
As vehicles, building heating and some industrial processes switch to electricity, electricity demand is expected to grow. The amount and timing of that growth depend on technology, policy, efficiency and how flexibly new demand can be scheduled.
More wind and solar can reduce fossil-fuel generation when their output is available, but their output varies with weather and time of day. A reliable, lower-carbon system therefore also needs a diverse mix of resources: firm low-carbon generation, storage, interconnectors, flexible demand and enough transmission and distribution capacity. Gas generation may continue to help balance the system during periods when low-carbon output is insufficient; its future role depends on the pace of investment and the wider energy transition.
More diverse supply can reduce exposure to any one fuel or import route, but it does not remove all price volatility or guarantee lower bills. Weather, outages, fuel markets, network constraints and the cost of new infrastructure can all affect system costs.
Marginal pricing and possible market changes
In the wholesale electricity market, the price for a settlement period is generally influenced by the most expensive generation needed to meet demand at that time. This is called marginal pricing. It helps coordinate supply and demand, but when gas is the marginal generator, movements in gas prices can influence the wholesale price paid across the market, including for electricity generated by other sources.
Market reforms are debated, including changes to how prices reflect location and network constraints, and greater use of long-term contracts. These options involve trade-offs for investment, reliability, consumers and system operation. The wholesale price shown on this dashboard is a market reading; it is not a measure of the marginal-pricing system's share of a household bill.
Changing the pricing mechanism would not automatically produce household savings. Any claimed saving needs to be assessed against the full costs of generation, balancing, networks, storage, backup and transition, as well as how costs and benefits are passed through to consumers.
Household bills: estimates need context
Wholesale energy costs and policy-related costs are only parts of a household electricity bill; bills also include network charges, operating costs, taxes and supplier costs. Estimates that assign a share of bills to policy costs or wholesale energy can vary by year, tariff, customer usage and accounting method. The percentage of a bill attributed to wholesale energy is not the same as the amount that could be saved by replacing marginal pricing.
For that reason, any figures such as an estimated 8–15% for policy-related costs or roughly one-third for wholesale energy should be treated as dated estimates, not fixed or universal shares. This dashboard does not calculate household bills or forecast savings from market reform.
Grid connections and the build-out
New generation and storage need suitable grid connections, and the connections queue has been a major delivery challenge. Government and regulators have announced changes intended to prioritise viable projects and speed up network delivery. These are plans and reforms in progress; their implementation and effect on individual project timelines will depend on delivery.
Read more about the announced Great British Grid and connections measures in Great British Grid, connections and bills. The announcement describes the intended benefits, but does not quantify guaranteed household bill savings.
What to look for in the dashboard
- Compare the wind, solar, gas and other generation series across different periods to see how the observed mix changes.
- Use the carbon-intensity readings as an indicator of emissions associated with electricity, not as a direct measure of household bills or all energy use.
- Check the reading timestamps: source feeds update at different times, and recent readings may be incomplete or delayed.
- Remember that half-hourly observations describe the system at those times; they are not long-term forecasts of the future generation mix.