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Starting with Sympheny

What is the Sympheny Web app?

The Sympheny Web app is a software to support the integrated planning of energy systems for buildings, neighborhoods, districts, villages and cities.  Given basic details about a site, the Sympheny Web app allows the modelling of the energy system and quickly evaluates a wide range of potential supply solutions and identifies a menu of optimal supply solutions for the site. Sympheny's built-in results dashboards provide detailed insight into the technological composition and performance of each of these optimal solutions.  By executing multiple scenarios in parallel, the effects of different assumptions concerning e.g. energy prices or site configurations can be evaluated.

What makes it unique?

The Sympheny Web app enables the identification of optimal energy supply solutions at a speed and level of detail not previously feasible.  This is enabled by Sympheny's powerful optimization algorithms, which quickly and comprehensively sift through thousands of possible supply solutions, and identify the optimal solutions with respect to the planner's objectives.  The algorithms solve energy balances for every hour of the year while accounting for complex site-specific supply/demand dynamics, interactions between different energy vectors, and the detailed techno-economic specifications of available technologies.

What can it be used for?

The Sympheny Web app can be used to identify the optimal energy supply solution for a given site, or to assess the expected performance of user-defined supply solutions.  It can be used to:

  • Optimize production technologies… Which energy production technologies are most suitable for a give site?  How should these technologies be dimensioned?  Is it better to supply heating and/or cooling from a single plant (centralized solution), or to supply each building/area individually (decentralized solution), or a combination of both (hybrid solution)?

  • Optimize renewables integration… To what degree is it possible to cover on-site energy demands with on-site renewable energy sources (e.g. solar, groundwater heat)?  What is the optimal mix of renewable resources and technologies to be used at a given site?

  • Optimize energy storage… Which storage technologies are most suitable for a given site?  To what degree can batteries enhance the site's energy performance in a cost-effective way?  What about seasonal (e.g. geothermal) energy storage?  What about hydrogen storage?

  • Optimize thermal networks… Does a thermal network make sense for this site?  What type of network (e.g. low-temperature, high-temperature) would be most efficient?  Which buildings or sectors should be connected to the network, and which should be supplied independently?  Which production technologies should supply the heating (or cooling) energy for this network?

  • Optimize grid interactions… Which energy vectors should be imported to the site, considering their respective cost structures and CO2 intensities?  To what degree is it possible to operate the site autonomously (e.g. independent of the electricity grid)?  What are the peak electricity withdrawals and feed-ins to/from the site with respect to the electricity grid for a given solution? 

  • All of the above in combination, and more...

What can it NOT be used for?

The Sympheny Web app is not intended for:

  • High resolution (building-level) optimization of sites larger than 15-20 buildings.  Larger sites can be optimized by aggregating buildings into nodes/hubs (max 15-20)

  • Detailed hydraulic optimization of thermal networks or detailed optimization of electrical networks

  • Optimizing the control or operational management of energy systems

Where should I start?

The best place to start is with the Example case, which is installed in every user's account at first sign-in.  After that, we suggest to follow the Tutorials described at to familiarize yourself with the different features of the software and how to use them.

What if I run into problems?

Contact us any time for support by clicking on the Help button (bottom-right corner of our web site) or at

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