Introduction

Nosy.jl is a composable, component-based energy system modelling and optimisation toolkit developed at the OECD Nuclear Energy Agency. It provides a Julia workflow for describing energy and commodities networks with LP and MILP formulations, solving them through JuMP-compatible optimisers, and inspecting the resulting costs, capacities, flows, prices and other characteristics.

The central idea is composition. A component starts with a compact model archetype, such as a dispatchable source, profile source, converter, storage unit, sink, demand, or line. Behaviors then refine that archetype with capacities, costs, ramping, unit commitment, yearly sums, reserve provision, or joint flows. This keeps the model vocabulary small while still covering a wide range of technologies.

Key capabilities

• Build systems using composable components at any level of detail.
• Model electricity, hydrogen, fuels, commodities, and CO2.
• Stay solver-agnostic through JuMP.
• Query flows and built-in metrics for capacity, cost, reserve, price etc.

Higher-level modelling with Posy2.jl

Posy2.jl builds on Nosy with standard technology constructors, input-data workflows, multi-zone power system modelling, and energy-system reporting. Posy2 components remain ordinary Nosy components, so studies can still be extended directly with Nosy's compositional API. See the Posy2.jl manual.

Licence

Nosy is available under the MIT licence.