A collection of open-source libraries and research frameworks designed to support energy system modeling, planning, analysis and optimization of long-term energy transition scenarios. It includes model generators, data processing tools, and visualization libraries that facilitate the development of energy system models and scenarios opmimized energy transition pathways.

multimod
The multimod R package is an effort to bridge alternative mathematical modeling frameworks and languages, particularly those used in energy system modeling. It defines a domain-specific language (DSL) for representing mathematical programming models in a unified, abstract format. multimod currently supports partial parsing of models written in GAMS (General Algebraic Modeling System), and is being extended to JuMP (Julia), Pyomo (Python), and GMPL (GNU Math Programming Language). Parsed models in multimod format can be rendered to LaTeX or other modeling languages. The package is designed to facilitate the exchange of mathematical models across different languages and solver frameworks, with the goal of simplifying the development of complex optimization models in energy systems and beyond.

energyRt
energy system modeling R-toolbox (/ˈɛnərdʒi ɑrt/) is a Macro-energy system modeling framework in R. This package offers a high-level interface that simplifies the development and application of complex energy system models. The package has served as the foundation for, and has been shaped by, the development of several large-scale electricity and energy system models, including USENSYS, IDEEA, and CEPRO (see below). It is currently underway a major overhaul to integrate with multimod concept and provide a more flexible and powerful modeling framework.

timescales
Nested timeframes and calendars for optimization and simulation models. A Calendar is a nested partition of a model year — a flat table of weighted leaf timeslices plus the ordered timeframes that produced them — and a single verb, recast_calendar(), moves data between temporal resolutions in either direction with conserved totals. Calendars can be filtered to partial-year samples that solve natively downstream. Developed alongside geoscales; the R implementation is the current focus, with a C++ core and Python bindings in development.

geoscales
Nested regions and spatial hierarchies for optimization and simulation models. The spatial companion to timescales. A Geoscale is a nested spatial partition — weighted leaf regions ("atoms") plus the ordered geoframes that group them. Aggregation and disaggregation are one operation, always routed through the atom layer, so geoframes that cross-cut one another — a grid zone straddling two states, say — need no special handling. The package ships no map data: it integrates with rnaturalearth and other sources through a pluggable provider interface, and records which source and boundary convention a hierarchy was built from.

merra2ools An R package and dataset for evaluating the potential output of variable energy resources (VER) — specifically wind and solar — globally, using over 40 years of hourly MERRA-2 reanalysis data. The dataset was assembled, and the package initially developed, to support the authors' internal and collaborative energy modeling studies, and is made available for public use. Further development will be guided by the needs of related research projects and contributions from the broader community.

energypal Color palettes and styling tools for energy-related data visualization. The goal of the project is to assemble a curated collection of color palettes tailored for energy-related visualizations, ready to use with ggplot2 and other plotting frameworks. The palettes are inspired by (and occasionally pirated from) publicly available visualizations used in major energy modeling projects and reports, with the goal of returning them to the public domain and promoting clarity and visual appeal in energy system research and communication.

• globalwindatlas
  Tools for accessing and processing high-resolution wind resource data from the Global Wind Atlas. The pakage also ranges areas by wind potential with estimation of potential installed capacity and annual energy production. The data can be used to refine estimates of wind energy potential in specific regions before feeding into energy system models.

• nrel.dev.api
  R functions for querying National Renewable Energy Laboratory (NREL) developer APIs, fetching and processing renewable energy datasets. NREL provides a range of of APIs for accessing houlry and sub-hourly solar and wind resource data which can complement other datasets, such as MERRA-2, and provide more localized information on renewable energy potential. Beyond fetching data, the package also includes the geographic scope of available datasets globally by collections (see datasets article on the package website).

• CEPRO
  China Electric Power Sector Province-level Model a reproduction of CEPRO model, originally developed for China Energy Modeling Forum project #2 (CEMF-02) to evaluate energy transition options for China’s electric power sector by the mid-century. The version CEPRO2.0 is planned after rafactoring of the energyRt package is completed. It will be based on the original model structure, but with an improved with finer resolution of renewable energy.

reneuro
European Energy System Model. An open, extensible model of the European energy system in energyRt, whose data, assumptions and processing steps are all inspectable. The current stage is calibration and testing: reproducing the core of the open PyPSA-Eur model and building out the workflow around it — reading networks, converting them to energyRt objects, sampling in space and time, solving, and checking results against PyPSA's own. Reproducing an existing model first gives a reference answer to diverge from deliberately. Planned extensions: alternative datasets, a review of the processing algorithms that turn raw data into model parameters, additional sectors, and links to other models. First release scheduled for August 28, 2026.

usensys.org
United States Energy System Optimization Model USENSYS is a linear programming optimization model for the United States energy system. It belongs to a class of models known as Macro Energy Models, also called Reference Energy System Models or Capacity Expansion Models (particularly in the context of the electric power sector). USENSYS optimizes the long-term development of the energy system considering alternative technological options, available resources, and policy options. Its primary objective is to determine the cost-optimal capacity expansion of technological chains while accounting for the current state of the system, resource- and policy-constraints.

IDEEA
Indian Zero Carbon Energy Pathways (IDEEA) is a collaborative open energy modeling initiative to develop tools and scenarios of India’s energy transition. The project aims evaluation a broad set of scenarios with high penetration of variable renewables and identify a set of most cost-efficient options of deep decarbonization and carbon neutrality for India for broad public discussion.

opendecarbonization
The aim of the Open Decarbonization project is to collect and/or develop open-source tools and data to streamline the development of energy system models and scenarios for decarbonization pathways. The project currently hosts tools used in MCET (Multi-Country Energy Transition) project with an attempt to build and evaluate a set of decarbonization scenarios for several countries.

Forthcoming ...

Contributions to any of the projects are very welcome! If you are interested in contributing to development or supporting the work please check out the [contribution guidelines] on the individual project pages or contact us directly SupportOpenSource@optimalsolution.dev.