User Tools

The jEPlus Simulation Server (JESS)

Version 2.1, © 2013 - 2020 Energy Simulation Solutions Ltd

[This page is under revision]

JESS is a software tool we have developed for accepting requests and running EnergyPlus simulations on a remote server. It is in fact an amalgamation of jEPlus+ tools, coupled with a server front and a database back-end. JESS has been installed on the DMU cluster. With a suitable client, users can access it easily and run simulations online.


JESS is a server that runs jEPlus/E+ simulations on users' behalf. To the users, it is a service which can be accessed online with a suitable client. The concept of JESS is illustrated below.

JESS diagram

What's the benefit of JESS? As soon as you start using building simulation on regular basis, you will realize that your ability to carry through a job is limited by the available computing power, as much as your skills and ingenuity. Sorry we cannot do anything about the latter; to the former, however, JESS may help. Running simulations remotely allows you to run many jobs at once, which is necessary for new design methods such as parametric study, optimisation and sensitivity analysis. It also allows you to go work on something else while waiting for the results, so you can multitask, too.

Key features

JESS is not only a way to run E+ simulations on the cloud. It has been designed to:

  • Support both jEPlus project and standard EnergyPlus simulations
  • Process jEPlus projects with high efficiency, especially for optimisation purpose
  • Provide an administrator's interface for configuration, management and accounting
  • Support different computing platforms, including public clouds such as Amazon EC2
  • Transparently support all E+ versions from V7.0 and above
  • We can also install your own customized version of EnergyPlus on the JESS server
  • Web interface for managing users and jobs (under development).

Supported platforms

JESS supports a number of computing platforms, including:

  • Computer clusters with batch-queuing system (e.g. PBS or SGE)
  • Connected (via local network or the internet) computers, including the commercial cloud instances
  • Single Multi-processor/multi-core computers
  • And, any combination of the above resources

The JESS package is operating system neutral, i.e. it can be installed on Windows, Linux, or Mac OS. In most cases JESS can be deployed without the administrator's privilege (except for changing firewall settings).


The JESS Online service is a JESS system deployed on the ENSIMS cluster. It is available for public access with free trial allowance provided.

The JESS software is not currently available as a standalone package. However, you can obtain a license as part of the consultancy contract with ENSIMS Ltd. This means we will help you install the software on your own computing hardware and provide training and support so you can take full advantage of the system.

The JESS service on the DMU cluster is no longer available to the external users.

The JESS Client

JESS is accessed using the JESS Client. Full details of the JESS Client is available in the JESS Client Users Guide.


Site Tools