UK Grid Sim — Can you match supply and demand on the UK grid? Real demand and generation data June 2024 to June 2025

{{ supply_GWh*0.001 | toFixed(1) }} TWh Supply
{{ demand_GWh*0.001 | toFixed(1) }} TWh Demand
{{ balance.unmet*0.001 | toFixed(1) }} TWh Gas demand
{{ balance.after_store1*100 | toFixed(1) }}% Zero Carbon
{{ balance.surplus*0.001 | toFixed(1) }} TWh ({{ 100*balance.surplus/supply_GWh | toFixed(1) }}%) Curtailment
{{ supply_GWh/demand_GWh | toFixed(2) }}× Oversupply
£{{ total_cost_per_mwh | toFixed(1) }} Total £/MWh
{{ balance.after_store2*100 | toFixed(2) }}% Met (w/ LDES)
Power view (GW)
Demand breakdown
Source Households
(million)
kWh/HH SPF TWh/yr
🏠 Standard grid
🌡️ Heat pumps
{{ heatpump.demand_GWh*0.001 | toFixed(1) }}
🚗 EVs
{{ ev.demand_GWh*0.001 | toFixed(1) }}
Total demand {{ demand_GWh*0.001 | toFixed(1) }}
Supply and Cost breakdown
Source % demand TWh/yr Capacity CF LCOE £/MWh Contribution
☀️ Solar
%
{{ solar_GWh*0.001 | toFixed(1) }} {{ solar_GWp | toFixed(1) }} GW @{{ 10 | toFixed(1) }}% +{{ solar_cost / demand_GWh | toFixed(0) }}
💨 Wind
%
{{ wind_GWh*0.001 | toFixed(1) }} {{ wind_GWp | toFixed(1) }} GW @{{ wind_cap_factor | toFixed(1) }}% +{{ wind_cost / demand_GWh | toFixed(0) }}
⚛️ Nuclear
%
{{ nuclear_GWh*0.001 | toFixed(1) }} {{ nuclear_GWp | toFixed(1) }} GW @{{ nuclear_cap_factor | toFixed(1) }}% +{{ nuclear_cost / demand_GWh | toFixed(0) }}
🔋 Storage {{ store1_discharge_GWh / demand_GWh * 100 | toFixed(1) }}% {{ store1_discharge_GWh*0.001 | toFixed(1) }}
GWh
@{{ store1.cycles | toFixed(1) }} cycles +{{ store1_cost / demand_GWh | toFixed(0) }}
🔥 Gas Backup {{ backup.demand_GWh / demand_GWh * 100 | toFixed(1) }}% {{ backup.demand_GWh*0.001 | toFixed(1) }} {{ backup.capacity | toFixed(1) }} GW @{{ backup.CF*100 | toFixed(2) }}% +{{ backup_cost / demand_GWh | toFixed(0) }}
Energy cost£{{ energy_cost_per_mwh | toFixed(1) }}/MWh
Grid cost£{{ grid_cost_per_mwh | toFixed(1) }}/MWh

Total cost£{{ total_cost_per_mwh | toFixed(1) }}/MWh
{{ csv_output }}
🔋 Battery storage
GWh
%
GW

Optimal dispatch holds charge for the deficits that actually set the gas backup fleet size (reducing backup capacity below), instead of emptying into the first shallow deficit. Set weight to 0 for energy-only optimisation.

£/kWh
£/MWh

The LCOS (levelised cost of storage) is calculated with the same discounted-cashflow method as the generator LCOEs: the capital cost per kWh of capacity above (default £245/kWh, based on the 600 MWh Kilmarnock South project at £147m), 1 year pre-development + 2 years construction, 20 year operating life, 8.9% hurdle rate and £3/MWh variable O&M. The capital cost is spread over the energy the battery actually discharges in the simulation, so the £/MWh falls the more cycles per year the dispatch achieves. Battery cost contribution to the system cost = annual discharged energy × LCOS, shown in the Supply and Cost breakdown.

🌊 Long duration energy store (LDES)
GWh
%
%
GW
GW

E.g. Hydrogen, e-Methanol, e-Methane. This technology does not yet exist at scale.