Energy Department releases Updated EnergyPlus and OpenStudio building energy modeling tools

The tools can now accept input in epJSON format.

May 02, 2018 |

The U.S Department of Energy (DOE) and the U.S. National Labs released updated versions of open-source whole-building energy modeling tools: the EnergyPlus engine and the OpenStudio software development kit (SDK) and application.

EnergyPlus 8.9.0 includes the ability to accept input in a JSON (Java Script Object Notation) format called epJSON. epJSON is derived from the existing IDF format and shares its object structure.

The JSON key-value structure supports schema validation as well as faster object and field lookups, and should make EnergyPlus schema evolution (e.g., the addition and deprecation of fields) simpler, DOE says.

EnergyPlus 8.9.0 includes:

  • An On/Off thermostat model
  • An option to disable “self-shading” effects
  • The ability to import shading schedules for a file
  • PVWatts calculations for estimating photovoltaic electricity production
  • A data driven model for hybrid air conditioners
  • Enhancements to data center modeling
  • New sizing and annual reporting options


EnergyPlus is available at

An upgraded version of OpenStudio 2.5.0, with new features is available at A key new feature in this release is support for EnergyPlus EMS (Energy Management System) sensors and actuators.

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