An example of what you build on lpspec. A capacity-expansion planner: the model is 69 lines of YAML, the job that solves and archives it 380 lines of Python, this site 1225 lines of Markdown and SQL over the parquet the job wrote, and the notebook 342 lines. All of it is in the source; nothing else is behind it.

Capacity-expansion pathway

One model, four scenarios, each solved one investment period at a time with the fleet carried forward. Every number on this page is a query over the parquet that lpspec archived, run by DuckDB in your browser.

Annualised cost per period

Click a period to select it below.

CO₂ emitted per period, t

Standing capacity, MW —

Built in the period, MW —

Selected period: .

What the cost is made of

Annualised cost of building, and of running, per technology and period. One column per scenario.

Emissions against the cap

Bars are what each period emitted; the step line is the cap it was given. A cap far above any fleet's emissions is left off the chart.

What builds, compared with

Capacity built per period, in MW, minus .

Every solve