Introduction

Posy2.jl is a country- and regional-level power system capacity expansion and dispatch model developed at the OECD Nuclear Energy Agency. It builds on Nosy.jl and provides a higher-level Julia workflow for constructing power and multi-carrier energy system studies from standard technology assumptions and hourly time series.

Posy2 components remain ordinary Nosy components. The component builders assemble model archetypes, behaviours, costs, capacities, emissions, storage relations, and connections, while Nosy supplies the shared simulation, optimisation, and querying machinery. A study can therefore use the Posy2 workflow and still be extended directly with Nosy.

Capabilities

• Assemble pre-conceived demand, generation, storage, conversion, and interconnection components.
• Load technology assumptions and hourly profiles from input data, or set them from Julia.
• Run multi-zone capacity expansion and dispatch with price-based or node-based interconnections and optional DC optimal power flow (DCOPF).
• Cover power-system features such as unit commitment, demand response, electric vehicles, hydrogen, and CO2.
• Inspect costs, capacities, balances, and prices, then export standard post-processing tables to a workbook.

Start with Getting Started for a simple example. Modelling Concepts explains how Posy2 maps study assumptions to Nosy objects, and Examples develops complete systems one feature at a time.

Licence

Posy2 is available under the MIT licence.