City energy system lab Blender 5.2

Size solar, wind, batteries and gas for a whole city, then watch 8760 hours of weather test it.

Scenario

Your energy mix

Battery before gas Gas before battery (reserve)

Economics and weather

Discount rate

Gas price (per MWh of fuel)

Costs are illustrative round numbers (2025 US$): solar $950/kW, wind $1,500/kW, battery $210/kWh + $110/kW, gas peaker $850/kW, 38 % efficient.

Targets and auto-design

Renewable share at least

Loss-of-load at most (hours/year)

Year at a glance

Where the money goes

Energy by month

Bars show generation by source. Where a bar rises above the white demand line, the surplus is stored, exported or curtailed.

Every hour of the year

Columns are days (Jan to Dec), rows are hours (00 to 24). Teal means surplus, orange means shortfall covered by storage, gas or imports, red means load not served.

Independent numerical checks

How much battery is enough?

Sweep the battery size with everything else fixed and compare loss of load with the energy-balance limit that no battery can beat.

Largest battery in the sweep

Pure renewables test: no gas and no link

Left axis: energy not served (GWh/yr). Right axis: loss-of-load hours. Dashed: energy-balance floor.