The U.S. Department of Energy's (DOE’s) open-source EnergyPlus building energy simulation program has helped architects and engineers design more efficient buildings for more than a decade. However, it can take a great deal of effort to input information and analyze the output. As a result, many have avoided using the program, while others have turned to third-party graphical user interfaces (GUIs) to increase its effectiveness. As entities such as the California Energy Commission, Hydro Québec, and Trane switch from DOE-2 to EnergyPlus, it is more important than ever to combine an easy-to-use GUI with the powerful capabilities of EnergyPlus.

Easier Access to EnergyPlus

To address the need for a more flexible, usable interface, the Simulation Research Group at Lawrence Berkeley National Laboratory (Berkeley Lab) worked with a public/private team to develop Simergy—a new GUI for EnergyPlus. Specifically designed for practitioners, the new, free GUI enables users to access the benefits of EnergyPlus much more easily. The beta version was released in October 2012 and is undergoing testing.

“The focus was on the end-user from the start of the project,” says the Environmental Energy Technologies Division’s (EETD) Philip Haves. “Berkeley Lab initiated and participated in a series of workshops where practitioners helped to define features that would enable them to use EnergyPlus effectively. We used their recommendations to develop a product that would meet their specific needs.”

Evolving Simergy Development Will Continue to Broaden Usability

Version 1 of Simergy will address design for new construction and is slated to be released in the first quarter of 2013. It will incorporate feedback from several months of beta testing, and users will benefit from the following key features:

• Capability to manage and evaluate design alternatives.
• Ability to translate building envelope geometry from CAD or Building Information Models (BIM) to Building Energy Models (BEM). Workflows are based on the industry standard protocols IFC-Design Concept BIM and gbXML, or they can be generated by Simergy. The CAD input is an improvement over previous GUIs, especially when using IFC.
• Extensive sets of libraries and templates for construction materials, schedules and HVAC equipment, and systems for both conventional and low-energy systems.
• Drag-and-drop component-based HVAC schematic editing.
• Summary reports that can be customized to the user’s desired level of detail.
• Interactive detailed results visualization.

Future developments are planned to include:

• Support for early-stage integrated design.
• Automated code compliance.
• For existing buildings, an integrated approach to semi-automated retro-commissioning, retrofit analysis, retrofit commissioning, and performance tracking for fault detection.
• Support for enhanced daylight modeling using a computationally efficient version of Radiance linked to EnergyPlus.

Using real-time EnergyPlus connected to a building control system, Version 2 of Simergy will be able to provide whole-building performance monitoring and fault detection. This capability will enable users to compare simulation and measurement for whole-building electric and gas, lighting, plug loads, and major HVAC components, to help maintain persistence of energy savings.

In addition, a professional version based on the free GUI is planned by one of the team’s private-sector partners.

Simergy development is conducted by a public/private partnership led by Berkeley Lab and including Digital Alchemy, Hydro-Québec, Infosys Technologies, and Trane, with input on user requirements and template design from Arup, HOK, SOM, and Taylor Engineering. It has been funded by the California Energy Commission, DOE, Hydro-Québec, Infosys, the Northwest Energy Efficiency Alliance, and Trane.