What is the THERMOS software?

THERMOS is an open-source, web-based software designed to optimise local district energy network planning processes and to support sustainable energy master planning.

THERMOS will offer your instant high-resolution address-level mapping and built-in energy demand estimations to undertake more sophisticated thermal energy system planning far more rapidly and cheaply.

THERMOS is free to use, and built with and for local energy planners. Try it out yourself and let us know if you agree with our claims! Optimised thermal network planning is only a few clicks away!

Where to access it?

Explore the THERMOS software instantly directly in your browser by clicking here.*

Watch the video below for guidance of your first steps in exploring the tool.

A detailed step-by-step guide and in detail information about the tool, its underlying methodologies and a applications can be found on our Training and Publication pages.

*For capacity reasons the size of the areas you can currently select is limited for the version accessible above. If you want to run the tool for larger areas please contact

How to apply it?

THERMOS application version 5 - Demo: Watch THERMOS project coordinator Martin Holley (CSE) demonstrating what optimised local energy planning looks like with the THERMOS software version 5 and how local energy planners and stakeholders can use the software for their purposes.

THERMOS software features

What is the THERMOS software?

The THERMOS free, open-source software offers local authorities address-level data for the optimised expansion of an existing system, the planning of an entirely new system, or assessing the performance of specific networks or non-networked solutions via direct comparison.

THERMOS works with high-resolution spatial information, accurate and specific data and can be tailored to the financial, energy, climate change circumstances of the local authority involved.

THERMOS’ unique features include:

  • a heat network optimisation model to find a cost-optimal (or near-optimal) network design from a problem specification;
  • OpenStreetMap for quick and easy map creation and analysis or the possibility to upload own GIS data;
  • heat map creation tool;
  • demand estimation method operating with limited data inputs in any location;
  • representation of variable pipe and dig costs (by pipe diameter), and network heat losses to the ground;
  • incorporation of capital costs for plant, pipes and connection, set against revenues from heat sales and monetised emissions;
  • interoperability with GIS formats, for model results and heat map export;
  • nearly comprehensive documentation of data requirements and model operation.

Additional features soon to come...