Why Sympheny

Why energy teams choose Sympheny

Sympheny helps engineering firms, utilities, municipalities, and developers turn slow manual planning workflows into fast, repeatable, investment-grade energy concepts.

70+
Companies served
10M+
Configurations run
50,000+
Combinations evaluated per run
Since 2020
In production use
5.1 TWh
Modelled across all projects
What you actually get

One model. Every carrier. Every technology you decide is in scope.

Sympheny Sankey energy-flow visualisation showing inputs (grid electricity, gas, solar roofs), technologies (gas boiler, air-to-water heat pump, solar PV), storage (hot water and Li-ion battery) and outputs (electricity demand, heat demand, surplus PV) in one diagram
Output from a real Sympheny project — electricity, heat, gas, solar PV and storage modelled in one optimisation.
The challenge

Energy planning is still too slow for the decisions it needs to support

Most energy planning workflows depend on manual data preparation, spreadsheet handoffs, and consultant bottlenecks. That makes scenario iteration slow, limits the number of options teams can seriously evaluate, and makes it hard to build the confidence that infrastructure investment decisions require.

Manual data prep consumes planning time

Hours spent cleaning GIS data, aligning tariffs, and building demand profiles by hand are hours not spent on engineering judgement. Projects take longer than they need to.

Too few scenarios get evaluated

When each scenario iteration is costly and slow, teams compare two or three options instead of ten. The best solution can get missed before a decision is made.

Justifying decisions is harder than finding them

Regulators, clients, and finance teams expect rigorous documentation. Outputs assembled from spreadsheets are harder to audit, explain, and update when assumptions change.

What makes Sympheny different

Purpose-built for multi-energy planning — not adapted from something else

Data and flexibility — without the trade-off

Most planning tools force a choice: bundled data with a black-box model you can't change, or full flexibility with no data to start from. Sympheny ships with technology cost, performance, and building energy data ready to run a scenario today — and lets you override every assumption, define your own technologies, and adjust performance curves when the project demands it. Your project data is yours alone: it is never used to train Sympheny's models.

Built for multi-energy system planning

Sympheny models heat, electricity, cooling, hydrogen, and storage together in one optimisation. Most tools handle one carrier. Sympheny handles all of them simultaneously.

Optimisation engine, not a spreadsheet

A physics-based MILP solver evaluates 50,000+ technology and capacity combinations per run, optimising across seven objectives — life-cycle cost, CO₂, self-sufficiency and more — simultaneously. You get defensible optima, not hand-tuned estimates.

Scenario comparison built in

Run multiple scenarios in parallel. Compare on cost, CO₂, self-sufficiency, and risk across the same baseline model — without rebuilding anything.

One tool covers the full project lifecycle

Project acquisition, strategic planning, detailed design, scenario comparison, and stakeholder-ready outputs — in one platform. GIS site view, Swiss and EU benchmark data, tariff structures, and in-app reporting (printable from the browser) are included. No stitching three packages together to cover one project.

Research-backed and production-proven

Developed from Empa / ETH Domain research in multi-energy optimisation, network-aware planning, and computational scaling. Used in 70+ real projects across Europe, the USA, and China — including the Nanoverbund thermal micro-grid in Basel (operational since 2023, with IWB), the entire 78-district energy roadmap for the City of Bern, and a multi-year city-wide strategy for IBC Chur. This is not a prototype.

Honest comparisons

Sympheny vs. the alternatives

vs. Spreadsheets

Spreadsheets don't scale to multi-energy complexity

Spreadsheet models are flexible, but they are hard to audit, difficult to share, slow to re-run, and nearly impossible to compare at scenario level. When a project has six energy carriers, 30 technology options, and three future demand assumptions, a spreadsheet becomes a liability — not an asset. Sympheny makes the same analysis repeatable, transparent, and faster. Every run is documented, every scenario is comparable, and the model can be re-used as inputs evolve.

BG Engineers ran six Pareto-optimal hydrogen variants in under 10 minutes — a multi-site sector-coupling analysis that would have taken weeks in spreadsheets.

Read case study
vs. Open-source tools

Open-source rigour, with people behind it

Open-source energy planning tools can be flexible and methodologically transparent, but most require programming skills, have steep learning curves, and ship without commercial support, onboarding, or a maintained roadmap. When a project deadline slips because a key contributor moved on, there's no one to call. Sympheny gives you the same kind of rigour — peer-reviewed MILP optimisation, transparent assumptions, exportable models — plus documented onboarding, web-based support with a 48-hour response window, API documentation, a 24/7 user guide, and a product roadmap shaped by paying customers. Backed by a Swiss team with PhDs from ETH Zürich and TU Delft.

vs. Legacy planning software

Built for the speed of early-stage planning, not the friction of detailed engineering software

Established desktop tools (HOMER, TRNSYS, NEPLAN, TOP Energy) are powerful for what they were built for — micro-grid sizing, hydraulic detail, electrical fault analysis. But they were designed for detailed engineering, not for the speed pre-feasibility, planning, and tendering require. Workflows are rigid, interfaces are dated, technical expertise is required, and teams end up buying and training on multiple packages to cover one project. Sympheny is web-based, usable by non-specialists, and built on the same engineering-grade primitives the best detailed-engineering tools rely on — Gurobi optimisation and Esri GIS — but exposed through a workflow that covers the full project lifecycle in one platform, from acquisition through strategic planning, scenario comparison, and client-ready reporting.

vs. Building internally

Internal tools are expensive to build and fragile to maintain

Building a multi-energy optimisation tool from scratch requires a team of energy modellers, software engineers, and data specialists — plus years of validation and testing. Most organisations that have tried discover that the ongoing maintenance burden exceeds the initial build cost. Sympheny provides a maintained, continuously improved platform backed by Empa research and a full engineering team. You get a product roadmap, onboarding support, and a solver that has been validated against real projects — without the overhead of owning it.

Honest boundaries

What Sympheny is not

Not a real-time energy management system

Sympheny is a planning tool, not an operations platform. It does not monitor live energy flows, control building systems, or replace BMS/EMS software like Siemens Desigo or Schneider EcoStruxure. It is used before infrastructure is built — to decide what to install and why.

Not a wholesale market modelling tool

Sympheny does not model national grid capacity, long-run electricity price curves, or policy scenarios at a regional or country level. Tools like Aurora, PLEXOS, or EnergyPLAN cover that space. Sympheny works at the district, campus, city, and site scale — where infrastructure decisions are made.

Overkill for single-technology feasibility

Sympheny can model a solar-only or EV-charging scenario — but if that's all you need, it's more than the job requires. The platform is built for projects where multiple energy carriers interact — heat, electricity, storage, gas, hydrogen — and where the right answer depends on how the system fits together.

Why now

Energy planning is getting harder, not easier

Electrification, heat networks, distributed storage, dynamic tariffs, carbon targets, and tightening regulation are all hitting planning teams at once. The number of technology combinations that need to be evaluated is growing. The timeframes for decisions are compressing. And the quality of evidence that regulators, clients, and finance teams expect is rising.

Teams that can evaluate more scenarios faster — and document their reasoning rigorously — are in a better position to advise, win projects, and commit to the right infrastructure. Sympheny is built precisely for that shift.

More energy carriers to model — electricity, heat, H₂, storage, mobility

More stakeholders requiring documented, auditable reasoning

Shorter project timelines with higher quality expectations

Carbon targets that require long-range scenario analysis, not point estimates

Tariff structures changing faster than static models can track

Planning capacity

What Sympheny gives back to your team

We don't publish a fixed ROI figure — every team's workflow and billing structure is different. What we can say is where the time goes in conventional workflows, and where Sympheny changes that.

Less time on manual data preparation — more time on engineering judgement

More scenarios evaluated and compared in the same project duration

Client-ready outputs explored in an interactive dashboard, not assembled by hand

Models that can be re-run as assumptions change, without rebuilding

Stronger confidence before infrastructure investment decisions

Time savings are directional estimates based on reported project experiences. Actual impact varies by team size, project type, and existing workflow.

Time to value

A short ramp-up to powerful, flexible energy modelling.

Sympheny gives expert users the flexibility of advanced energy system optimisation without a long implementation burden. For users with prior experience in optimisation or energy-system modelling, the platform can usually be understood in less than a week. Once workflows are established, many studies can be set up in around 30 minutes.

See why most teams recover the license cost after 1-2 projects

Deep analysis for engineers. Everyday utility for the whole team.

Sympheny is built for the engineer who needs full analytical depth — and designed so project managers, decision-makers, and wider team members can review models, interrogate scenarios, and act on outputs without needing deep technical training. Onboarding a new team member takes about an hour.

Time savings vary by project complexity, input data quality, and team experience. Examples reflect common workflows after the relevant setup is in place.

Track record

Results from real projects

Empa / ETH Domain spin-off
Peer-reviewed optimisation methods
Swiss Made Software certified
ISO 27001-aligned security

We hold our security practices to ISO 27001 standards — not currently certified

GDPR-compliant, EU data residency options
Watt d'Or 2025 — Swiss Federal Office of Energy

Nanoverbund project · IWB, ETH, Empa, HSLU, Sympheny

Explore the optimisation research
What our customers say

“Thanks to Sympheny, we can now develop more precise energy concepts for our customers and create added value for them.”

Oliver Meyer
Oliver Meyer
Energy Engineer, Elimes AG · Brig, Switzerland

“Sympheny supports our strategic energy planning in an ideal way. The flexibility is extremely convincing and the sensitivity analysis provides security in finding solutions.”

Andreas Wirz
Andreas Wirz
Chief Digital Officer, Eicher+Pauli AG · Bern, Switzerland

“Digitalization with Sympheny helps us to develop decentralized energy concepts and creates security for investments in new infrastructures.”

Martin Derungs
Martin Derungs
CEO, IBC Energie Wasser Chur · Chur, Switzerland

See whether Sympheny fits your planning workflow

In 30 minutes, we'll run a scenario based on your project type — live in the tool, no slides.