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ISH 2023 – Count us In!

After a four-year break, the International Sanitary and Heating Fair (ISH) will be held again. Vela Solaris is exhibiting its solutions and applications for simulating energy.

Finally, meeting up with well-known, and new, people “live” again. Finally, trade fairs again!

We’re looking forward to joining the International Sanitary and Heating Fair (ISH), March 13-17. The world’s leading trade fair for HVAC + Water in Frankfurt am Main is reopening after a four-year break. Its visitors get access to expert knowledge, specialist enterprises, and energy system and energy supply providers.

Are you going to be there? Visit us in Hall 5.1, Booth A63!

The ideal tool for planning energy systems

Get to know simulation-based planning, design, and optimization of integrated energy systems with Polysun, first-hand at our booth. Learn how our tool can be used to meaningfully visualize and simulate state-of-the-art technologies – from solar thermal collectors to PV modules and heat pumps to ice storage systems. Plus, exchange your thoughts with our experts on the potential applications of Polysun. 

The key benefits at a glance:

  • Visualization of various solutions for energy systems quickly and easily:
  • Using simulation, various potential energy systems for supplying electricity, heating and cooling requirements can be created and compared for energy efficiency, self-sufficiency, and cost-effectiveness. The benefit: Visualization of reliable and transparent results.
  • Design PV rooftops efficiently and easy-to use reports:
  • PV roof design, including inverter sizing and stringing, as well as 3D graphics and meaningful reports on expected PV yield, self-consumption, and profitability analysis.
  • Target-oriented optimization of energy systems in both preliminary and detailed construction planning:
  • How can grid withdrawal be reduced through optimized heat pump control? How much does the integration of batteries or electric mobility increase self-consumption of PV production? What size of technical storage is optimal? Polysun provides reliable answers to these planning questions to exploit the full optimized potential of a project.
  • Provide innovative products and solutions for energy systems online and automatic lead generation:
  • Polysun is integrated into numerous web applications via API and automates the lead and quotation process by providing custom-fit, digitally generated system designs.

With Polysun, we provide the ideal solution to accelerate the development of efficient energy concepts, regardless of construction project size – from individual buildings to city districts.

Have you become curious? Here you can find more information about the exhibition: Link.

We look forward to welcoming you!


New building ProfiCamp Eintracht Frankfurt:


Mainova provides sustainable energy for the Eintracht family!

pictures: ©Eintracht

Mainova optimizes the operation of the state-of-the-art plant technology of the ProfiCamp Eintracht Frankfurt and relies on the simulation software Polysun.

Mainova supplies more than one million people in Frankfurt am Main with electricity, gas, heat and water and is a convincing high-performance partner in the operation of sophisticated plant technology. The focus is on decentralized and environmentally friendly energy generation with high plant efficiency and optimal energy use. The professional soccer club Eintracht Frankfurt has therefore decided to place the energy supply of its new ProfiCamp in the hands of Mainova. The new ProfiCamp comprises the 800-square-meter fitness area, including a whirlpool, and a 400-square-meter administration building, including a 120-seat staff restaurant. The building standard corresponds to a passive house and thus to the most modern requirements.

Mainova defines the optimal operation of the energy systems:
The experts at Mainova analyzed the existing energy system in detail, with the aim of ensuring efficient use of the renewably generated energy. The system concept for meeting heating and cooling requirements consists of seven heat pumps (three air-to-water heat pumps with a cumulative output of 450 kW and four brine-to-water heat pumps with a cumulative output of 240 kW), solar thermal collectors on 107 square meters of roof surface, a geothermal collector and a gas boiler. A particular challenge was the prediction of the user behavior, which has large demand peaks due to the training periods. In addition, the geothermal collector is located in a water protection area with corresponding requirements for the cooling of the ground.

The Polysun software is used to test operating variants in a target-oriented manner:
Mainova’s experts use the Polysun software to map the existing system with all its components and to simulatively define the optimal operation. The goal was to use the gas boiler only to cover a few hours. In a first step, a simplified rough simulation was carried out in Polysun and the generators were combined in a meaningful way. This allowed a quick comparison of variants of different control concepts and a basic decision in this respect. In a second step, the simulation in Polysun was refined based on the selected control concept and the generators were mapped in detail. In addition, different consumption scenarios were stored and the robustness of the energy supply for the provision of heat and cold throughout the year was checked. The simulation experts from Vela Solaris supported the simulative mapping in Polysun by setting up the corresponding hydraulic schemas.

Polysun system template

The system technology supplies renewable energy during operation:
In the meantime, the new ProfiCamp has been occupied by the Eintracht family and is reliably supplied with renewable energy by Mainova. The plant will be monitored over all operating points for two years and further optimized with the help of Polysun. Mainova also expects to be able to identify and eliminate the causes more quickly in the event that the actual operation fails to meet the target state, thanks to the simulation with Polysun.

Key aspects:


Mainova AG

Energy system components for simulation

  • Solar thermal
  • heat pumps (air-water, water-water)
  • geothermal collector
  • gas boiler
  • technical storage tank for heating and cooling energy
  • hot water tank

Services provided by Vela Solaris

Provision of base model of simulation with Polysun software considering Mainova requirements and model refinement.


Successful definition of operational control, taking into account the efficient integration of different producers as well as constraints related to water conservation.


Get in touch for additional information


Offre d’emploi: Postuler maintenant

Tu cherches un défi?

Nous nous engageons pour des systèmes énergétiques!

Responsable des ventes techniques pour le logiciel de planification des systèmes d’énergie renouvelable

Vela Solaris AG est la première entreprise mondiale dans le domaine du développement de logiciels pour les systèmes énergétiques des bâtiments. Grâce à notre gamme de logiciels Polysun, nos clients peuvent planifier de manière simple et fiable des systèmes énergétiques innovants pour les bâtiments et les quartiers. Des sociétés d’ingénierie, des fabricants et des universités de renom dans plus de 40 pays font confiance à Polysun.

Afin de développer nos activités commerciales, nous pourvoyons un poste de:

Responsable des ventes techniques pour le logiciel de planification des systèmes d’énergie renouvelable, 80%-100%

Tes tâches:

  • Expansion des activités de licence et de service de notre gamme de produits logiciels Polysun dans la région DACH, avec une responsabilité commerciale correspondante.
  • Conseiller les clients potentiels B2B sur les possibilités de simuler les systèmes énergétiques innovants des bâtiments.
  • Représenter l’entreprise en tant qu’expert en simulation de bâtiments lors de congrès professionnels et d’événements de mise en réseau.
  • Conception et mise en œuvre indépendantes de mesures de vente, telles que des webinaires en ligne ou des démonstrations de logiciels.
  • Optimisation des processus et outils de vente ainsi que des canaux.
  • Collaboration dans les projets de développement de logiciels.

Ton profil:

  • Tu es enthousiaste à l’idée d’élargir tes connaissances en matière de planification numérique des systèmes énergétiques.
  • La vente est ta passion! Tu t’efforces d’établir une relation honnête et collaborative avec les clients et de créer des résultats win-win. Une expérience professionnelle dans la vente de produits et/ou de services dans le secteur de l’énergie est un avantage.
  • Ta méthode de travail est structurée et communicative. On peut compter sur toi au sein d’une équipe.
  • Tu disposes d’une expertise dans le domaine de la technique du bâtiment et/ou de la technologie solaire (diplôme correspondant d’une école technique supérieure/université).
  • Tu parles couramment l’allemand et français.
  • La connaissance du logiciel Polysun ou d’autres outils logiciels dans le domaine de la technique du bâtiment est un avantage.

Notre offre:

  • Le meilleur produit de sa catégorie: Le logiciel Polysun est réputé dans le monde entier pour la simulation fiable et de haute qualité des systèmes énergétiques.
  • Une équipe de haut niveau t’attend. Nous te soutiendrons pendant ton initiation, nous sommes serviables et extrêmement compétents. Nous aimons travailler en équipe!
  • Des tâches intéressantes pour prendre le pouls de l’avenir dans les secteurs de l’énergie, de l’informatique et de la construction.
  • Grande liberté créative et espace pour la créativité.
  • Formation sur le tas en tant qu’expert commercial pour la simulation de systèmes énergétiques chez Polysun.
  • Un environnement de travail moderne avec un modèle de travail flexible (par exemple, le choix du lieu de travail).

Si tu souhaites saisir cette opportunité professionnelle, nous nous réjouissons de recevoir ta candidature!

Envoie-nous tes documents par e-mail à Angela Krainer,

Job offer: apply now as Java Developer!

Ready to develop software for renewable energy systems?

We have the job for you!

At Vela Solaris AG we are committed to making the planning of innovative energy systems simple and reliable! With our in-house developed software Polysun, we are world leaders in the digital simulation of energy systems for buildings. Renowned engineering companies, manufacturers and universities in over 40 countries rely on Polysun. Our customers realize efficient and sustainable solutions by cleverly linking all commercially available technologies – from PV, heat pumps, battery systems and energy management systems and many more.

To strengthen our software development team, we are filling a position as:

Java Developer for renewable energy systems, 80%-100%

Would you like to work with us on an innovative and digital energy future after your engineering studies or with your practical experience? Do you enjoy working with numerical models? Is it important to you to use your expertise for sustainable solutions? Then we have an offer for you!

Your tasks:

The further development of the simulation software Polysun is your main task: Here you can optimally apply your skills in software programming and your interest in renewable technologies and develop new technological features

  • Together with your teammates, you work out the requirements for the further development of models and functionalities in Polysun and implement them directly. In doing so, you will work your way into Polysun’s dynamic time-step simulation and gradually expand your expertise in model simulation.
  • We support and accompany you in the development of the necessary software engineering skills when it comes to keeping the quality of Polysun high with the help of architecture decisions, process automation and usability. We rely on git, Jenkins, Jira and an established development and quality assurance process.
  • You ensure the software quality in joint code reviews.
  • Bug analysis and according software improvements are also part of your tasks.

Your profile:

The following skills and characteristics distinguish you:

  • You are passionate about developing clean modular code and have strong knowledge of an object-oriented programming language (C#, VisualBasic.NET or preferably Java) and optionally SQL.
  • You bring in-depth expertise in modeling renewable energy systems (electrical and thermal) and have a relevant university or college degree or bring the necessary practical experience.
  • You have a strong interest in physical processes and have ideally already developed software in the field of renewable energy systems (e.g. photovoltaics, battery storage, thermal energy systems).
  • You are fluent in German and English.

Our offer:

We make sure that you can live up to your full potential:

  • We take the time to train you on the job. We support you in your desire for continuous personal and professional development.
  • You will constantly learn new things and take on extremely exciting tasks at the pulse of the future in the energy, IT and construction industries.
  • Creativity is important to us – we will ensure that you are given the necessary space to think outside of the box.
  • With us you will work in a modern working environment. You decide whether you want to use our central and friendly office in Winterthur or work from your home office and also benefit from flexible working hours.
  • A top team is waiting for you. We support you with questions, are helpful and extremely competent.

Does our job advertisement appeal to you?

Then we are looking forward to getting to know you! Please send your application documents by e-mail to Angela Krainer,

Customers ask us: Post # 1

To what extent does the installation of a heat pump reduce the gas consumption of a building?

This is a question frequently asked by our customers: engineers who plan and advise on energy systems for buildings and districts.

The answer varies depending on the project. In a specific project example, the answer is 65% (reduction of annual gas consumption from 27.4 MWh to 9.5 MWh, shown here over the course of a year).

Comparison of energy supply options with Polysun

Getting this answer took us little time and the result is precise! With our simulation software Polysun energy systems are planned reliably and in a few steps.

Do you have this or another question about your energy system project?

Please contact us:

or get to know our software Polysun at a free webinar:

EnBW Contracting

Demonstrating reliable energy system options convinces B2B customers

EnBW Contracting

EnBW Contracting plans future-oriented energy supply concepts for the housing industry with Polysun.

When it comes to energy, more and more business customers are turning to an experienced specialist offering a contracting partnership. The reason is obvious: an optimized energy supply concept and the long-term predictability of energy costs are more than ever the decisive keys to success. Because these two factors provide customers with security and thus competitive advantages on the market.

EnBW Contracting GmbH has adopted this approach and is leading the way innovatively. The wholly owned subsidiary of the energy group EnBW Energie Baden-Württemberg AG (EnBW) offers customers reliable solutions tailored to individual project characteristics.

EnBW Contracting focuses on supplying energy to industrial customers, municipalities and the housing industry. Demand-driven energy supply concepts and professional operational management enable this target group to concentrate on its core business.

Olaf Kleineschallau, Team Leader Planning & Realization at EnBW Contracting, and his team are responsible for the planning of these energy concepts, from the initial idea to the comparison of options to the detailed planning of the best solution and the subsequent realization of the plants. In view of the increasing complexity of projects, there was a greater need to supplement the self-programmed design programs, which had been steadily optimized over the years, with a standard software solution. Olaf Kleineschallau explains, “As a supplement, we were looking for a tool that could handle multiple energy technologies and always provide us with the best possible option for the customer.”

After an evaluation phase with various software solutions and extensive tests in real operation, EnBW Contracting decided on Polysun from Vela Solaris.

The solution
For the application field “residential area from 100 residential units” with efficiency standard KfW 55, different supply options with gas, air-to-water and earth-to-water heat pumps as well as solar thermal were defined in the Polysun software. These templates are now used right from the start. As requested, the experts at EnBW Contracting can also use the software from Vela Solaris for the most complex simulations. For example, they use it to design PV in combination with battery storage for own consumption optimization and simulate the combination of different heat generators from different sources – earth, water, sun, air.

The result
EnBW Contracting’s customers have a specific useful energy requirement for which they can obtain combined supply variants in every conceivable form.

“For example, solar energy use in combination with other energy sources,” says Olaf Kleineschallau. “No matter whether it’s a complex interconnection, different energy sources for heat pumps or even solar thermal energy – we can plan what seems conclusive to us and our customers with Polysun.”

“We also very much appreciate the competence of Vela Solaris’ technical support, which is always available to us very quickly. This allows us to continue working quickly,” adds team leader Olaf Kleineschallau.

Key points

At a glance

  • Customer: EnBW Contracting GmbH
  • Sector: Energy supply contracting in the form of the provision or supply of heat, steam, cooling, compressed air, electricity from CHP and the operation of the associated facilities, with particular emphasis on renewable energies
  • Location: Stuttgart


  • Increasing need to supplement the self-programmed design programs, which have been continuously optimized over the years, with a standard software solution.
  • It must be possible to map all technologies, especially the combination of different energy technologies.
  • It must be possible to show the best possible option transparently.


  • Polysun Designer
  • Service Vela Solaris: Creation of standardized energy system templates for use in Polysun.


  • Special use cases of different energy sources for heat pumps and use of solar thermal energy can be solved with Polysun.
  • The reliability of the calculated options is guaranteed
  • EnBW Contracting convinces its customers by showing valid simulated options and a supported recommendation for the best option.

Contact us to learn more about what our software Polysun and our simulation experts can do for you!

Get in touch

eZeit Ingenieure

Demonstrating reliable energy system options convinces B2B customers

EnBW Contracting

Das berliner Planungsbüro simuliert die komplexe energetische Sanierung eines großflächigen Gebäudekomplexes in Polysun: Nachhaltiges Konzept wurde umgesetzt und Fördermittel gesichert.

eZeit Ingenieure ist ein Planungsbüro für Architektur, Gebäude- und Energietechnik. Das Berliner Unternehmen hat sich auf energieoptimiertes, nachhaltiges Bauen fokussiert. Das bedeutet ganzheitliches Denken, Planen, Finanzieren und Umsetzen – vom städtebaulichen Großprojekt bis zum Wärmebrückendetail. Das Leistungsspektrum der Planer umfasst dabei alle Bereiche des Wohn- und Gewerbebaus, vom Einfamilienhaus über große Wohnanlagen bis hin zu ganzen Quartieren. Sowohl im Neubau als auch in der Sanierung legen die Spezialisten großen Wert auf maßgeschneiderte Konzepte für wirtschaftlich energieoptimierte Bauprojekte.


In einem Berliner Mehrfamilienhaus galt es, eine energetische Sanierung des Bestandsgebäudes zu bewerkstelligen. Das Haus mit rund 2.400 Quadratmetern Wohnfläche hatte ursprünglich 17 Wohneinheiten (WE) im Bestand. Ein Anbau (3 WE) und ein neues Dachgeschoss (4 WE) mit insgesamt sieben neuen Wohneinheiten wurden im Zuge der Sanierung des Mehrfamilienhauses realisiert.

Keinesfalls trivial war die Anforderung. Die Erneuerung des Leitungsnetzes musste „minimalinvasiv“ erfolgen. Der Grund: Bereits vorhandene Schornsteinzüge im Gebäude sollten sich weiterhin nutzen lassen. Und auch die vorhandenen Heizkörper sollten bestehen bleiben.

Im Detail geschah dann bei der Sanierung Folgendes: Die alten Gasetagenheizungen wichen einer modernen Energiezentrale. Das Energiekonzept umfasste eine Abluftwärmepumpe, eine Sole-Wärmepumpe mit neun Tiefenbohrungen und einen Gas-Spitzenlastkessel in Verbindung mit Solarthermie und Photovoltaik auf den Dachflächen. Für die Installation der technischen Gebäudeausrüstung (TGA) inklusive Elektroinstallationen ließen sich dann tatsächlich die alten Schornsteinzüge nutzen, es wurden keine zusätzlichen Schächte im Bestand benötigt. Auch die Heizkörper wurden nicht ausgetauscht.

Ganz im Sinne der eZeit-Ingenieure sollte die Energiesanierung des 1900 erbauten Mehrfamilienhaus ganzheitlich erfolgen. Denn nur derart wird der Umbau zukunftsfähig gemacht. „Das Prinzip war also, dass sich alles in der Planung und anschließenden Sanierung nicht nur auf die Gebäudehülle konzentrierte. Erst das exakte Zusammenspiel von Gebäudehülle und Gebäudetechnik hat zuverlässig die Reduktion der CO2e-Emissionen bewirkt“, so Bernd Paarmann, auf Gebäudeenergie- und -informationstechnik spezialisierter Ingenieur des Berliner Unternehmens.

Die Konsequenz dieser Gemengelage: Vor dem Umbau müssen eine Vielzahl an Weichenstellungen erfolgen. Hierfür lohnte sich die simulationsgestützte Planung, Auslegung und Optimierung der ganzheitlichen Energiesysteme mit Polysun von Vela Solaris.

Bild@eZeit Ingenieure


In Polysun konnten Bernd Paarmann und seine Kolleginnen und Kollegen die Eingangsparameter – etwa Gebäudegeometrie, Hülle, Nutzung, TGA im Bestand – erfassen. Erst daraufhin erfolgte eine genaue, auf das Gebäude zugeschnittene, Planung der Gebäude- und Energietechnik. Ebenso flossen darin standortspezifische Faktoren wie z. B. lokale Wetterdaten ein.

Um kostenschonend zu planen, sollte natürlich auch die Erzeugerleistung nicht zu groß, sondern genau passend zu dem jeweiligen Projekt gewählt werden. Gleichzeitig galt es, die Komfortansprüche an Warmwasser und Heizen/Kühlen zuverlässig zu decken. Auch hier kam Polysun zum Einsatz.

„Ebenso haben wir mit Polysun berechnet, wie sich zukünftig die Energiekosten im Betrieb der Anlage im Vergleich zum unsanierten Zustand und den alten Gasetagenheizungen verhalten“, so Paarmann. Hier ging es insbesondere um das Thema „grüne bezahlbare Energie“.

Auch der Aspekt: „minimalinvasive Sanierung“ ließ sich in Polysun zuverlässig simulieren. Da sich im Bestandsgebäude einige Schornsteinzüge nicht nutzen ließen und auf zusätzliche neue Schächte verzichtet werden sollte, musste die ursprüngliche Trennung des Heizungsnetzes in Hoch- (bestehende Heizkörper und Warmwasser) und Niedertemperatur (Flächenheizung Neubaubereich) aufgehoben werden. Derart blieb nur noch ein Hochtemperatur-Netzheizkreis übrig, der – wenn nötig –heruntergemischt wird. Der Simulation in Polysun wurden neue Varianten hinzugefügt und durchgerechnet, denn es ergab sich die Fragestellung, ob das geplante Energiekonzept auch unter diesen ungünstigen Bedingungen noch funktioniert. Dabei war wichtig, dass die gewünschte und erforderliche Jahresarbeitszahl weiterhin erreicht wird und wie die Auswirkungen auf den Anteil der regenerativen Energien sowie der Strom-Anteil im Verhältnis zum fossilen Anteil sind.

Letzterer Aspekt war deshalb entscheidend: Da in die Wirtschaftlichkeitsbetrachtung des Energie- und Sanierungskonzeptes auch mögliche Fördermittel einfließen konnten, wurden die konkreten Jahresarbeitszahlen der Wärmepumpe exakt simuliert. Die dadurch ermittelte Effizienz kann einen Bezug von Fördermitteln tatsächlich ermöglichen, was die Sanierung sowohl für die Bauherren als auch die Mieter attraktiver macht.


„Da wir durch die Simulation die Anteile der verschiedenen Energieträger wie Strom, Gas und Umweltwärme ermitteln konnten, war es uns möglich, eine Prognose über die Entwicklung der Energiekosten im Vergleich von neuer und alter Anlagentechnik zu erstellen“, so Experte Paarmann. „Es ließ sich damit deutlich für den Bauherren und die Mietparteien zeigen, dass bei weiter voranschreitender Stromwende – der erneuerbare Anteil im deutschen Strommix steigt kontinuierlich – und steigender CO2-Bepreisung unser Energiekonzept im Hinblick auf die Energiekosten im Vergleich zum Weiterbetrieb mit Gas deutlich zukunftsfähiger ist.“

Durch die Substituierung von fossilem Gas mit Strom und Umweltwärme konnten die eZeit-Ingenieure so ein Anlagenkonzept realisieren, das auf die Energiewende und die damit verbundenen Preisentwicklungen in Deutschland vorbereitet ist, einen wirtschaftlichen Betrieb ermöglicht und einen kleinen ökologischen Fußabdruck aufweist, mit dem sicher die Zielanforderungen für das Jahr 2045 erfüllt werden können.

Die Förderprogramme des Bundeswirtschaftsministeriums erfordern eine bestimmte Jahresarbeitszahl. Der Nachweis darüber muss bei komplexeren Anlagensystemen über eine Simulation erbracht werden. „Für dieses Bauvorhaben haben wir mit der Simulation die Fördermittel für die energetische Sanierung gesichert. Diese geringeren Investitionskosten resultieren in der Umlage in einer geringeren Kaltmietenerhöhung für die Mietparteien.

Durch die Simulation war es den Berliner Ingenieuren ebenfalls möglich, die notwendigen Planungsänderungen der Stränge und der damit verbundenen Anhebung des Temperaturniveaus in Hinblick auf die Kriterien Anteil erneuerbarer Energie, Wirtschaftlichkeit und zukünftige Energiekosten zu überprüfen. „Mit der Simulation von Polysun konnten wir zuverlässig sicherstellen, dass sich das gewünschte Anlagensystem umsetzen lässt, sich für Förderprogramme qualifiziert und einen wirtschaftlichen Betrieb der Anlage garantiert.“, zieht Bernd Paarmann ein zufriedenes Fazit des Polysun-Einsatzes.

Key points

At a glance

  • Customer: EnBW Contracting GmbH
  • Sector: Energy supply contracting in the form of the provision or supply of heat, steam, cooling, compressed air, electricity from CHP and the operation of the associated facilities, with particular emphasis on renewable energies
  • Location: Stuttgart


  • Increasing need to supplement the self-programmed design programs, which have been continuously optimized over the years, with a standard software solution.
  • It must be possible to map all technologies, especially the combination of different energy technologies.
  • It must be possible to show the best possible option transparently.


  • Polysun Designer
  • Service Vela Solaris: Creation of standardized energy system templates for use in Polysun.


  • Special use cases of different energy sources for heat pumps and use of solar thermal energy can be solved with Polysun.
  • The reliability of the calculated options is guaranteed
  • EnBW Contracting convinces its customers by showing valid simulated options and a supported recommendation for the best option.

Contact us to learn more about what our software Polysun and our simulation experts can do for you!

Get in touch

Spannendes Jobangebot

Demonstrating reliable energy system options convinces B2B customers

EnBW Contracting

Ingenieur/in Gebäude-Energietechnik für Serviceprojekte (80% bis 100%)

Bei Vela Solaris AG setzen wir uns dafür ein, dass die Planung von innovativen Energiesystemen einfach und zuverlässig gelingt! Mit unserer inhouse entwickelten Softwarepalette Polysun sind wir weltweit führend in der digitalen Simulation von Gebäudeenergiesystemen. Mit Polysun und unseren Serviceleistungen können unsere Kunden und Kundinnen einfach und zuverlässig Energiesysteme für Gebäude und Quartiere planen, entwickeln, bauen und betreiben.

Für den Ausbau unseres Geschäftsbereichs Support und Services suchen wir per sofort oder nach Vereinbarung eine/n Teamplayer/in als Ingenieur/in Gebäude-Energietechnik für Serviceprojekte (80% bis 100%).

Deine Aufgabe:

Deine Hauptaufgabe ist es, unsere Kundinnen und Kunden (renommierte Ingenieurunternehmen, Hersteller von innovativen Energiesystemkomponenten und Energiedienstleister) bei dem erfolgreichen Einsatz unserer Simulationssoftware Polysun zu unterstützen!

  • Konzeption und Durchführung von Software-Schulungen (Online oder vor Ort beim Kunden).
  • Beratung bei fachlichen Kundenanfragen zu der erfolgreichen Anwendung von Polysun (2nd level support).
  • Erstellen von Energieanlagekonzepten in Gebäude- und Solartechnik im Auftrag von Kundinnen und Kunden.
  • Stukturierte Entgegennahme von Kundenfeedback zur Weiterentwicklung von Produkten und Services.
  • Unterstützung des Verkaufsteams bei technischen Fragestellungen.

Dein Profil:

Für diese Aufgabe suchen wir ein neues Teammitglied, dass an der Kundenschnittstelle kompetent und lösungsorientiert auftritt. Es ist uns auch wichtig, dass deine Teammitglieder auf dich zählen können! Zudem bringst du idealerweise auch folgende Skills und Eigenschaften mit:

  • Fundiertes Wissen im Bereich Energietechnik (entsprechender Abschluss Hochschule).
  • Stilsichere und kundenorientierte Kommunikation in Deutsch und Englisch. Französisch von Vorteil.
  • Idealerweise praktische Erfahrung mit Polysun-Software.  
  • Erfahrung mit weiteren Softwaretools im Bereich Gebäudetechnik (z.B. IDA ICE, Revit) von Vorteil.
  • Zwischen 25 und 35 Jahren alt.  

Unser Angebot:

Auf dich wartet ein Top-Team! Wir unterstützen dich bei Fragen, sind hilfsbereit und fachlich äusserst kompetent. Zudem bieten wir dir:

  • Äusserst spannende Aufgaben am Puls der Zukunft in der Energie-, IT- und Baubranche.
  • Grosse Gestaltungsfreiheit und Raum für Kreativität
  • On-the-job Ausbildung als Simulationsexperte für renommierte Energiekonzepte.
  • Modernes Arbeitsumfeld mit flexiblem Arbeitszeitmodell.
  • Sinnstiftende Tätigkeit in einem internationalen Umfeld.

Wenn Du diese berufliche Chance ergreifen willst, dann freuen wir uns auf deine Bewerbung!

Bitte sende uns deine Bewerbungsunterlagen per E-Mail an Angela Krainer,

Welcome Michael!

Since the beginning of the year Michael Hönes strengthens the team. It’s time to introduce him:

A team member with a wide range of skills!

Michael holds both a Master in Business Administration CDI Collège des Ingénieurs GmbH, Munich and a double Master from the European Institute of Innovation and Technology (EIT) in Energy Innovation and in Energy Engineering and Management. He combined his studies with stays in Turin, Paris, Munich, Stockholm and Lisbon. So communicating in different languages is no problem for Michael.

In addition to his studies, Michael has deepened research questions in the field of renewable energy and digitalization as a research assistant at the IPA – Fraunhofer Gesellschaft and the University of Stuttgart and completed internships at HELLA with a focus on corporate strategy and Daimler with a focus on electromobility.

Steep start at Vela Solaris.

At Vela Solaris, Michael has taken on and expanded responsibility from the very beginning. Today, he is responsible for customer support and, together with his teammates, ensures that technical and professional questions regarding the simulation of energy systems with the Polysun software are answered quickly and competently. The further development of the support processes always with a view to customer satisfaction and efficiency is also one of his tasks. In addition, he leads ambitious digitalization projects based on the Polysun API at the customer interface. Last but not least, he bundles customer feedback for the attention of the software development team and assumes product responsibility for Polysun SPT.

How is Michael doing with these versatile tasks? Time to ask him a few questions.

Three questions for Michael:

What was the deciding factor for you to come to Vela Solaris?

It was a great opportunity for me to be able to participate in the simulation of energy systems in the building sector. Finally, I was completely convinced by the warm welcome I received from my colleagues during the last job interview.

What do you appreciate about your work at Vela Solaris?

I really appreciate the great transparency in the company – it makes me happy and motivates me to know at an early stage where the company is heading and how our products and services are developing.

Vela Solaris allows each employee to play to their strengths. It’s a great feeling to always be assigned where I can help the company the most.

Did we forget to mention something about you?

In the past, I would never have believed that I would move to Switzerland. Now it makes me very happy to be so well received here at Vela Solaris and to live so close to the mountains. For me, seizing opportunities, even the obvious ones, is the best way to personal success!

Looking for a new challenge?


Demonstrating reliable energy system options convinces B2B customers

EnBW Contracting

The building technology association suissetec launches the web app “Building Technology Calculator” and relies on the calculation core of the Polysun API

The Swiss-Liechtenstein Building Technology Association (suissetec) is the employer and industry association for building technology and building structures with around 3,500 member companies, including manufacturers/suppliers, planners and installers from the plumbing, heating, air conditioning and cooling sectors.

suissetec pursues the goal of making its member companies fit for the market requirements and digital planning processes in the field of building technology. The association saw a particular need for action in the area of designing building energy systems. Until now, there has been a lack of a reliable tool that enables the rapid comparison of different options of an energy system, especially in an early project phase. To close this gap, suissetec developed the web app “Gebäudetechnikrechner, in english: Building Technology Calculator”. For the simulation of the energy systems, Vela Solaris was chosen as the development partner and the Polysun computing core was integrated as an API.

The following benefits are offered by the calculator:

  • Through a simple and user-friendly browser interface, the user configures different possible variants of an energy system.
  • When selecting the individual system components (e.g. PV, heat pump, storage, etc.), the user accesses the extensive Polysun database and can select manufacturer-specific or anonymous products.
  • When configuring the energy system, the user is supported with suitable suggestions, for example on the necessary installed capacity of the heat pump. The suggestions can be flexibly adapted by the user.
  • If the simulation is initiated by the user, the Polysun calculation delivers meaningful results, for example for analyzing the fuel demand or the CO2 emissions.
  • The building technology calculator also integrates price information from suissetec on investment and operating costs, which correspond to the usual industry average. This means that a meaningful profitability analysis based on the Polysun simulation is also possible at the push of a button.

selection of options and comparison made easy

With the building technology calculator, a system decision is made in a time-saving and reliable manner. The next planning steps are also supported: Once an option has been selected, the calculator enables the user to seamlessly continue processing and optimizing an energy system in the Polysun software. The created options can be dragged into the Polysun desktop application with the stored data. Here, further optimization steps can then be taken, such as refining the steering and control system.
The building technology calculator was realized in a joint project between suissetec and Vela Solaris. It has been available since August 1, 2021, and users are very happy with the results:

From suissetec’s point of view, the joint project with Vela Solaris is thus a great success:

Are you interested in integrating the Polysun computational core into your front-end application? Learn more about our the Polysun API:


Would you like to test the building services calculator from suissetec? Click here for the demo version (available in german, italian and french):



Contact us to learn more about what our software Polysun and our simulation experts can do for you!

Get in touch

Grünheide (DE) urban district

Demonstrating reliable energy system options convinces B2B customers

EnBW Contracting

reich+hölscher dares to break new ground and convinces with an innovative energy concept – simulated with Polysun.

The Grünheide urban district is being built in the northwest of Bielefeld’s Mitte district in Germany. With around 600 residential units, it will be one of the largest in the city. On an area of eight hectares, the investor Amandla International GmbH & Co. KG (Unna) plans to build 400 city apartments. In a further construction phase, additional buildings with around 100 residential units may be built. Special properties for care facilities or student apartments are also being considered. Another important part of the concept is a daycare center.

In the competitive bidding process for the energy concept, The Bielefeld engineering office reich + hölscher clearly came out on top. It was important to the investor to realize a future-oriented solution with the lowest possible CO2 balance, which at the same time efficiently and economically utilizes the possibilities of a centralized energy generation. reich+hölscher examined various options under this prerequisite: The reference scenario was the heat supply via the district heating connection of the Bielefeld municipal utility and the operation of the local heating grid with a flow temperature of 75 degrees. Alternatively, different options for the operation of a “cold” local heating grid with a flow temperature of 45 degrees and the integration of air-water heat pumps were investigated.

For a meaningful comparison of options, reich+hölscher relied on the Polysun simulation software and the cooperation with Vela Solaris from the very beginning. All the options investigated could thus be simulated and compared in terms of security of supply, energy efficiency and profitability. It became clear which option was the most convincing: In the selected option, electricity from the sun and heat from the air is used for heating the apartments based on a flow temperature of 45 degrees. This is perfectly sufficient for the heating systems in the nearly 400 apartments. A second part of the electricity is used to heat hot water for bathrooms and kitchens in each building. The houses are connected by a local heating grid to several water storage tanks in the houses, which hold a total of 60,000 liters. A third part of the electricity generated goes into lighting, comfort and technology for the residents. The major advantages of this solution are that the energy is generated directly in the neighborhood: short pipe runs and low supply temperatures minimize transport losses.

In the further optimization of the chosen options, Polysun’s simulation results provided valuable insights. For example, it was possible to reduce the installled capacity of the heat pumps by 40% and thus significantly increase the profitability. In addition, individual questions could be answered specifically by simulation. One question concerned the choice of pipe insulation, taking into account economic efficiency. The energy losses of different pipe systems were simulated and compared with the investment costs. Another question concerned the necessary expansion of the installed capacity of the heat pumps when additional construction fields are added. Here, it was also possible to analyze the load scenarios simulatively over the time axis and to optimally dimension the correspondingly necessary expansion of the heat pumps’ installed capacity. The energy system project already set up in Polysun in the competition phase was used throughout and enriched with input data, from the design planning to the implementation planning to the BAFA application within the framework of the Heat Networks 4.0 funding (Förderung Wärmenetze 4.0).

An important aspect concerns the future planned use of the Polysun simulation software: BAFA stipulates monitoring of the energy system over eleven years. reich+hölscher therefore plans to compare the simulated results from Polysun with the measured actual values to ensure quality assurance during operation.
What is particularly appreciated about the cooperation with Vela Solaris is the competence in setting up the simulation projects in Polysun. With the support of the Vela Solaris simulation experts, the setup and further optimization of the energy projects succeeded reliably and in a time-saving manner.

Key points

At a glance

  • Customer: EnBW Contracting GmbH
  • Sector: Energy supply contracting in the form of the provision or supply of heat, steam, cooling, compressed air, electricity from CHP and the operation of the associated facilities, with particular emphasis on renewable energies
  • Location: Stuttgart


  • Increasing need to supplement the self-programmed design programs, which have been continuously optimized over the years, with a standard software solution.
  • It must be possible to map all technologies, especially the combination of different energy technologies.
  • It must be possible to show the best possible option transparently.


  • Polysun Designer
  • Service Vela Solaris: Creation of standardized energy system templates for use in Polysun.


  • Special use cases of different energy sources for heat pumps and use of solar thermal energy can be solved with Polysun.
  • The reliability of the calculated options is guaranteed
  • EnBW Contracting convinces its customers by showing valid simulated options and a supported recommendation for the best option.


Contact us to learn more about what our software Polysun and our simulation experts can do for you!

Get in touch

PCM and latent thermal storage successfully simulated with Polysun

A latent thermal storage system with PCM capsules is simulated in Polysun in an advanced thesis at HSLU.

In his thesis at the Lucerne University of Applied Sciences and Art (Switzerland), Mr. Markus Lacher tackled the problem of simulating latent thermal storage systems with PCM capsules using the Polysun software from Vela Solaris.

First, the system of latent thermal storage was analyzed in detail to determine the different influencing parameters. Then, a parameter analysis was performed on the fluid properties specified in Polysun to understand the calculations of the storage temperatures as well as capacities in Polysun. The next step was to program three different PCMs and test the PCMs through an experimental simulation. Then, the programming of an experimental memory in Polysun was done, giving the opportunity to validate the memory design. Finally, the simulation of an energy system of a single-family house took place.
The experiment was successful: “The simulations showed that both PCM and the latent thermal storage in Polysun can be simulated with the given components. The simulated capacity of the experimental storage tank of about 7.97 kWh corresponds quite closely to the measured capacity of 7.9 kWh or the temperature calculated 8.1 kWh.”

Find here the complete thesis (in german): link

Vela Solaris congratulates on the exciting work!

Are you interested in learning more about the possibilities of simulating PCM and latent thermal storage with Polysun? Feel free to contact us at

campus of Lucerne University of Applied Sciences and Art (Switzerland)

With the Polysun software from Vela Solaris you can rely on a multi-practice simulation of your energy system with reliable results in terms of functionality, energy efficiency and profitability – from single-family homes to districts, worldwide and for all market-standard technologies.

Education and Sports Campus Bürstadt, Hessen, Germany

Demonstrating reliable energy system options convinces B2B customers

EnBW Contracting

Team für Technik convinces with simulation-based planning and has successfully completed the feasibility study for a sophisticated supply concept.

As part of a pilot project for the “Healthy and Socially Integrative City” project and with the support of numerous sponsors, including the Dietmar Hopp Foundation, a new education and sports campus with a total area of around 32,000 m2 is being built in Bürstadt (Hessen, Germany). The existing site, which houses several sports clubs, is being transformed into an open campus with a multifunctional sports facility as a meeting and exercise area for all generations. In addition to existing facilities, modernized and newly created areas will be available in the future. Two gymnasiums, several clubhouses and a youth center are already part of the campus, as is the municipal outdoor pool. Two artificial turf sports fields and an open-air hall, as well as a new floodlighting system, are intended to expand the possibilities and provide more convenience for year-round use of the sports facilities. In addition, a new education center is to be built as a multifunctional building at passive house level, forming the heart of the campus. The goal is to operate the entire campus in a climate-neutral manner with the help of a well thought-out innovative energy concept.

Sustainable and innovative energy concept
Team für Technik GmbH was entrusted with the planning of this energy concept. The innovative engineering company for energy and supply technology with offices in Munich, Nürnberg, Berlin and Karlsruhe specializes in ecologically and economically sustainable solutions based on many years of experience in consulting, planning and construction supervision. Since 1998, Team für Technik has been successfully advising clients on all issues relating to energy and supply technology.
In addition to the further development of existing facilities, new buildings and planned future expansions of existing buildings had to be taken into account at the same time for the education and sports campus in Bürstadt. In addition, the use of the area as an open space, by clubs and also for events, as well as the structural condition of the buildings had to be taken into account. A wide variety of energy requirements were the result. A particular challenge was that the temperature requirements of the heating system had to meet both the existing facilities with a higher target temperature and the new buildings with a lower target temperature. The existing gas boiler for the outdoor pool, for example, was retained only as an outage reserve. The solar thermal system of the outdoor pool will be modernized and also integrated into the heating network.
In addition, the energy supply had to be planned in accordance with the regulations for a heating network 4.0 (Wärmenetze 4.0) in order to meet the high sustainability targets and secure the corresponding subsidies.

Simulation-based planning

Team für Technik has been using simulation-based planning with Polysun from Vela Solaris for years. In the case of the Bürstadt education and sports campus project, it quickly became clear that planning could only be carried out accurately and efficiently with the help of simulation due to the complexity of the project. For this purpose, different options were initially compared with each other in an early project phase and mapped in Polysun. This was done in close cooperation with the experts from Vela Solaris. An initial model was developed so that the engineering team only had to make refinements and optimizations. “The first rough model of the Polysun simulation was already created during an on-site workshop in our office in cooperation with Vela Solaris and later completed on our behalf by Vela Solaris in a very timely manner in remote cooperation – so we could focus on refinement and optimization. For short-term consultations, Vela Solaris was always available in an uncomplicated and extremely competent manner!”, says Fabian Speer, Team für Technik GmbH.
A local heating network with a groundwater heat pump and cascading supply with decentralized heat pumps as well as a closed distribution network for electricity with photovoltaics was finally selected as the favored option for the holistic energy supply of the education and sports campus. With Polysun, this variant was further developed and refined: The optimization of the energy management system provided decisive criteria for the planning of the automation. In addition, the appropriate dimensioning of the solar thermal system could be defined. This led to an increase in the solar coverage ratio of around 4 percent as well as an increase in the system annual performance factor (SJAZ) from 4.1 to 4.9 through solar thermal groundwater preheating.

Successful function test and feasibility study

Finally, the functional test was reliably performed with simulation in Polysun and the criteria for compliance with the funding regulations for the heating network 4.0 were ensured. These formed the basis for the complex funding application to the German Federal Office (BAFA), especially with regard to groundwater utilization (simulation of heat extraction and corresponding volume flows) as well as the funding share for the PV systems (share of own consumption for heat generation).
Thanks to consistent simulation, the entire energy supply concept was presented transparently and convincingly to the client and other stakeholders. The simulation-based planned holistic energy concept for the education and sports campus in Bürstadt was ultimately convincing, was accepted by the city council and the company was commissioned with the implementation planning.

Key points

At a glance

  • Customer: EnBW Contracting GmbH
  • Sector: Energy supply contracting in the form of the provision or supply of heat, steam, cooling, compressed air, electricity from CHP and the operation of the associated facilities, with particular emphasis on renewable energies
  • Location: Stuttgart


  • Increasing need to supplement the self-programmed design programs, which have been continuously optimized over the years, with a standard software solution.
  • It must be possible to map all technologies, especially the combination of different energy technologies.
  • It must be possible to show the best possible option transparently.


  • Polysun Designer
  • Service Vela Solaris: Creation of standardized energy system templates for use in Polysun.


  • Special use cases of different energy sources for heat pumps and use of solar thermal energy can be solved with Polysun.
  • The reliability of the calculated options is guaranteed
  • EnBW Contracting convinces its customers by showing valid simulated options and a supported recommendation for the best option.


Contact us to learn more about what our software Polysun and our simulation experts can do for you!

Get in touch

Polysun by Vela Solaris with advanced BIM functions

simulation software in BIM projects for designign energy systems
Polysun BIM

Software enables digital simulation of energy systems for holistic, optimized and visionary construction projects also in BIM projects

Winterthur, CH, June 08, 2021 – Vela Solaris AG announces a new version of its software add-on Polysun® BIM. With the new version, import interfaces can be defined so that data can be integrated into the simulation software even more easily and quickly. The automated data import for heatload and meteo data is supported with a wide variety of sources and is independent of the data formatting. Thus, exactly those data can be automatically imported and continuously updated that are necessary for further simulation-based planning in Polysun. In addition, plan specifications from the BIM project can be conveniently stored for the energy system and results can be evaluated at the push of a button. In this way, requirements for the energy system in terms of comfort, funding criteria and system efficiency are visible during every planning phase. Polysun BIM also offers software-supported plausibility checking of input data, enabling the highest process quality and minimizing manual errors.
Digital planning processes are becoming increasingly important, as is interdisciplinary collaboration. Simulation is an integral part of efficient and cross-technology planning of energy systems. With the Polysun BIM Add-On, all energy system results remain transparently documented and deliver added value up to the operational phase – for easy quality assurance.
Availability: The BIM Add-On is available from June 7, 2021 and can be seamlessly integrated into existing Polysun solutions as an extension. A free trial version is available on the company website or upon request. Continuous development of the Polysun software as well as the BIM Add-On and associated updates enable a steady expansion of the range of functions.
Polysun enables simulation-based planning, design and optimization of holistic energy systems – both for buildings and for comprehensive quarters. Internationally, planners, architects, energy service providers, manufacturers and distributors of energy system components, and renowned research institutes rely on Polysun for detailed simulation of energy systems. Whether for the planning of the Überseeinsel in Bremen, on the part of energy suppliers such as Stadtwerke Düsseldorf or for sales support at manufacturers such as the Vaillant Group: Polysun offers the highest simulation accuracy for the respective planning processes. The software has extensive manufacturer-specific component data and combines components for covering heating, cooling and power requirements, such as electrical and thermal storage units, photovoltaic modules and heat pumps.
Seamlessly integrated simulation offers numerous advantages – for planners of energy systems and building technology right through to building owners: on the one hand, it presents planning processes transparently and enables planning to be adjusted and checked at any time, as well as providing a fact-based basis for decision-making. On the other hand, the high level of transparency from the early planning phase through to operation plays a significant role for the building owner, who now no longer has to rely exclusively on his expertise and that of his project partners, but has resilient data at his disposal.
“Digital simulation of renewable energy systems is an essential prerequisite in the smart planning of buildings and neighborhoods. The demand for our software solutions and services is increasing enormously. This is a trend that will intensify, especially in connection with model-based planning in BIM projects,” says Angela Krainer, Managing Director of Vela Solaris.

levelup with Polysun

TH Rosenheim competes again in Solar Decathlon Europe 21.

There are many ideas for sustainable urban development. The crucial thing is to follow up the ideas with action. The Solar Decathlon Europe 21 (SDE21) therefore has the motto “Design – Build – Operate”. University teams from all over the world come together to design, build and operate solar houses with a neutral or even positive energy balance.

levelup with Polysun

After the great success at the Solar Decathlon Europe 2010 as “Vice World Champion in Solar Building”, the Rosenheim Technical University of Applied Sciences is taking on the challenge again. The levelup project at the TH Rosenheim is currently being driven forward by an interdisciplinary project team from various courses of study and faculties. At their side are about 20 advising professors from different courses of study. “levelup” stands for a modular, flexible addition in lightweight wood construction, adaptable to almost all 1950s to 1970s buildings. This creates an innovative solution for redensification in cities that can be applied to the largest proportion of Germany’s building stock of multi-family houses.
levelup relies on a renewable energy supply: The levelup is to be brought to an energy-plus level, which also includes the supply of the existing building stock over its life cycle. Photovoltaic modules for solar power generation on the entire facade and on the roof contribute to this.
For the planning of the solar energy system, the interdisciplinary levelup team relies on the Polysun simulation software from Vela Solaris. The energy production can be simulated precisely over the entire life cycle. With Polysun, the students succeed in gaining planning reliability and verifying whether the requirements regarding the energy-plus level are achieved.
The competition will run until the summer of 2022, when the houses built will be evaluated and awarded prizes. So the levelup team is in the middle of its work! The whole Vela Solaris team keeps its fingers crossed!
Learn more about the levelup project: link

Demand for commercial storage for peak shaving is on the rise.

pv magazine updated market overview of commercial and grid storage systems. Polysun is mentioned as a simulation software for storage integration.

The demand for commercial storage for peak shaving is on the rise. pv magazine updated its market overview providing interesting insights: Manufacturer prices decreased by an average of five percent. The market is still small in absolute numbers – but with a strong trend towards growth. That is what we at Vela Solaris are also experiencing: The demand for simulation of energy systems with storage capacities is increasing! With Polysun it is possible to show the impacts of storage integration on the increase of solar self-consumption, peak-shaving for grid fee reduction or on the integration of electric vehicles. We are pleased to be the only simulation software listed in pv magazine’s current market overview.

Learn more about the market overview of pv magazine:

SunPeople project builds energy simulation platform – using the Polysun API

The Interreg FCE SunPeople project aims to increase the development of a decarbonised heat energy service in the residential and commercial sectors. The project’s objective is to demonstrate and test on 15 sites, in Plymouth and Lorient, a cost-competitive, sustainable heat energy service based on heat pump and solar technologies. This service will enable to reduce carbon emissions on these sites an estimated 62.8 tons of carbon over a one-year contracting period corresponding to the project.

The service will rely upon a building energy simulation platform to scale up the zero-emission heating industry. The simulation of building energy schemes will be carried out using the Polysun simulation by Vela Solaris in the cloud (Polysun API).

comparing energy systems

The SunPeople project including the reference simulation platform approach relying upon Polysun software was introduced by Vela Solaris and ALOEN at this year’s conference of the European Heat Pump Association (EHPA) on Digitalization in the H&C industry, on March 9 2021.

Missed it? Access the slides here.

Further information on the Interreg FCE SunPeople project: Link

Polysun is accredited by Minergie

Our simulation software Polysun is now officially accredited by Minergie for the calculation of PV yields.

Minergie is committed to quality assurance in the planning, construction and operating phases of buildings in Switzerland. The three building standards Minergie, Minergie-P and Minergie-A already set clear requirements in the planning phase with regard to quality, efficiency and comfort. Today, depending on the region, 10% to 25% of new buildings are planned according to Minergie.

For the verification of the PV yield, Minergie wants to ensure a comprehensible and uniform verification of the Minergie applications. We are very pleased that our simulation software Polysun is now officially accredited by Minergie as a calculation tool for the verification of PV yields.

Polysun takes into account the efficiency of the modules, the orientation and size of the plant, the exact location and relies on current weather data for the PV yield forecast. With Polysun, even higher yields than the standard value of 800 kWh/kWp can be claimed. In Switzerland, yields of 1,000 kWh/kWp and more are possible at most locations. It is therefore worthwhile to calculate PV yields with Polysun and use them for Minergie applications.

Source: Minergie

Would you like to learn more? Just get in touch with us:

Polysun goes BIM: The new Polysun release increases planning quality!

The actual software release of Polysun makes the use of simulation of energy systems in digital planning even easier.

The digital simulation of energy systems generates a clear added value: various aspects are tested at an early stage and the quality of the planning increases. This significantly reduces investment and operating costs.  The current release of Polysun makes the use of simulation in digital planning even easier: relevant information on the current planning status is available at the push of a button. The fulfilment of set requirements for the energy system is immediately visible. Data import and export is automated and supports interdisciplinary teamwork. This also enables, for the first time, the seamless integration of energy system simulation in BIM projects.  Simulation results can be generated and validated even faster. As a digital twin, the planning data is reproducibly available and generates added value right up to the operating phase. This makes quality control easy! Our development partner, the engineering services company Amstein & Walthert confirms: “This makes planning energy systems a pleasure! We were able to test Polysun-BIM on a concrete construction project and see great potential in using the software!”

Highlights of the Polysun software release, version 12, with Polysun BIM Add-On:

  • Polysun-BIM supports automated data exchange. Meteorological data, heating load data and simulation results are thus available to the project team at the desired location at all times.
  • The data import is subject to an automated quality check. Implausible and incomplete data are recognized immediately.
  • Key performance metrics (KPM) from the construction project are defined for the energy system in Polysun on a project-specific basis. The achievement of set KPMs and deviations are available at any time at the push of a button.
simulation software in BIM projects for designign energy systems
New Polysun BIM add-on is available: test now for free!

Would you like to find out more?

Experience the new Polysun BIM add-on live and start testing right away.

Tenna does an internship at Vela Solaris

Tenna Söndergaard is currently doing an internship year at Vela Solaris. This is an important part of her training as an energy and environmental technology engineer at the ZHAW (Switzerland). After only three months, Tenna is already an integral part of the team. Time to ask her a few straightforward questions:

Why did you choose us in the first place? You surely had other options!

For me, both privately and professionally, sustainable interaction with the environment is important. At Vela Solaris renewable energy systems are made possible. This appealed to me a lot. In addition, the planning software Polysun is developed in-house at Vela Solaris. This is also an exciting aspect for me. I am convinced that in the future energy systems will be planned exclusively digitally. You were therefore my ideal candidate for an internship!

Many thanks! Where do you currently see the benefits of your internship for your future career?

My tasks are very diverse: I solve support cases for customers, test new features of the software, assist with billing and even write exam questions for external courses in building services engineering. I benefit greatly from getting to know work processes from A to Z. I learn very practical things in the process: talking to the managing director of an engineering company about his customer concerns has become a matter of course for me. In addition, I have the opportunity to apply my theoretical knowledge to practical issues every day. My goal is to expand my practical knowledge in the simulation of entire energy systems – I find this to be a very good starting point.

How do you experience working in our team – especially in the current situation?

Unfortunately, we rarely see each other personally at the moment, and I only see certain team members virtually. But at Vela Solaris there is a great basis for welcoming new team members like me within a very short time. There are very different personalities in the team, which I also find good. Everyone is friendly, open and collegial. I get the feeling that I am making a contribution that is clearly appreciated. This makes me very happy and also makes it easy to work together virtually.

Vaillant Group

Demonstrating reliable energy system options convinces B2B customers

EnBW Contracting

The Vaillant Group relies on the simulation software Polysun from Vela Solaris for the distribution of its innovative heating systems in various European country organisations. In close cooperation, the existing solutions are aligned with the digital channels of the Vaillant Group in order to increase sales success.

With about 14,000 employees worldwide, the Vaillant Group with its headquarters in Remscheid, Germany, is one of the market and technology leaders in the heating technology sector. The Vaillant Group offers systems for heating, cooling and hot water – primarily on the basis of renewable energies. “In sales, it is central to show the customer transparently which energy yields and costs are associated with the proposed heating system. With Polysun, yield forecasts are easy and convincing”. The cooperation with Vela Solaris was successively expanded. Today around 100 employees use Polysun to simulate the yield of renewable heating systems.

With a Polysun online application, customers in different countries have the opportunity to choose between available Vaillant heating systems and make simplified yield forecasts themselves:”This enables us to enter into direct dialogue with customers and conduct discussions based on their needs”. The online solution was implemented in a joint project by the Vaillant Group and Vela Solaris. “The success of the project is always the top priority for Vela Solaris and is ensured with full commitment.” The online yield forecast is currently being expanded in the heat pump sector to offer customers additional interactive options on the Vaillant website.

Contact us to learn more about what our software Polysun and our simulation experts can do for you!

Get in touch

Polysun server license

Step-by-step guide for Polysun server license installation

  • To activate the license on the server you need the network license manager, which is located in the Polysun installation directory ( If you have not yet installed Polysun on the client, you can download Polysun here: Link.
  • In the ZIP file there is a README with instructions for activation on Windows, Linux and Mac servers. Please install the license manager on the server and perform the activation there (not on the clients).
  • To activate the license you need the instructions for “Case 2: To activate one or more client installations of Polysun with license manager on external server” in the README. Attention: When determining the “Locking Code” with the “Wechoid Tool” for Windows servers, all checkmarks except “DiskID” must be removed (see screenshot below). The code must be copied including the asterisk at the beginning.
  • If it is not possible for a client to connect to the server, you may need to enable UDP-ports 5093 and 5099 in the firewall. You can find more details here: Link

If you have any questions or problems with the setup, please contact us at or via our support hotline: +41 55 220 71 00.