siz energieplus

What siz energieplus does

siz energieplus (legal name: Steinbeis-Innovationszentrum energieplus) is a non-profit applied research institute and affiliated institute (An-Institut) of Technische Universität Braunschweig, operating within the Steinbeis network of approximately 1,100 transfer companies and 5,500 experts. Founded in 2013, the institute employs 38 people (with approximately 29 named researchers on its team page, led by Prof. Dr. M. Norbert Fisch) across offices in Braunschweig (headquarters) and Stuttgart. It develops sustainable, climate-neutral energy supply concepts at building, district, and city scales, with research specialization in hydrogen technologies (production, storage, distribution, and reconversion), heat pump systems, geothermal energy, energy storage, Building Information Modeling (BIM), AI-based operational optimization, and dynamic energy simulation.

The institute's technology stack includes open-source simulation and design tools: QuaSi (district energy simulation), GenSim (thermal building simulation based on EnergyPlus), Sodele (PV yield simulation using the Python library pvlib), ReSiE (a new Julia-based calculation kernel replacing QuaSi), and the WPSOURCE pre-check tool for heat pump design. Its novel Power-to-Gas&Heat (P2G&H) approach, pioneered in the Klimaquartier Neue Weststadt Esslingen project, achieves electrolysis efficiency increase from approximately 55% to up to 90% through heat integration with building heating loads. The simulation tools are integrated into commercial BIM platforms through partnership with Digital Building Industries AG (DBI) into the Building Configurator. Notable technical milestones include the world's first 1 MW AEM (Anion Exchange Membrane) Multicore Electrolyser from Enapter at H2-Terminal Braunschweig, and participation in researching Germany's largest ground basin heat storage (45,000 m³) in Meldorf combined with a novel rotation heat pump.

Revenue is generated through publicly funded research grants and commissioned consulting. Funding sources include the German Federal Ministry of Education and Research (BMBF), Federal Ministry for Economic Affairs and Climate Protection (BMWK), European Regional Development Fund (ERDF), Lower Saxony Ministry for Science and Culture, and the Volkswagen Foundation. Customer and partner organizations span cities (Braunschweig, Esslingen, Stuttgart, Freiburg, Bremen, Hamburg), municipal utilities (BS|ENERGY, Stadtwerke Esslingen, Winnenden, Wertheim, Tauberfranken), industrial firms (ArcelorMittal Bremen, Georg Oest, Ebner), and research institutions (multiple Fraunhofer institutes, DFKI, multiple TU Braunschweig institutes, ZSW, OFFIS, ZAE Bayern, RWTH Aachen). Flagship engagements include the H2-Terminal Braunschweig research facility (BMBF funding exceeding €20 million total) and the TEN.efzn research program (approximately €60 million combined funding across 15 Lower Saxony institutions).

Name

siz energieplus

Legal name

Steinbeis-Innovationszentrum energieplus

Website

https://siz-energieplus.de

Company type

Private

Operating status

Operating

Headcount range

11–50 employees

Short description

siz energieplus is a non-profit applied research institute (An-Institut) of TU Braunschweig within the Steinbeis network. It develops climate-neutral energy supply concepts and open-source simulation tools for buildings, districts, and cities, serving municipalities, utilities, and industrial partners across Germany.

Ownership category

akta.pro rank

Product category

Applied Energy Research and Consulting

NAICS

Plumbing, Heating, and Air-Conditioning Contractors (23822), Architectural, Engineering, and Related Services (5413), Steam and Air-Conditioning Supply (221330)

SIC

Air-Cond & Warm Air Heatg Equip & Comm & Indl Refrig Equip (3585), Cogeneration Services & Small Power Producers (4991)

akta.pro primary industry

Energy & Sustainability Management (Energy Audits/Optimization/Carbon & ESG Programs) (IMAIAAAM)

akta.pro secondary industries

HVAC & Industrial Ventilation (Chillers, AHUs, Exhaust, Filtration) (EUAEAFAE), Sustainability & ESG Consulting (BPAHACAK), Commissioning, Testing & Energization Services (Pre-Commissioning, Grid Code Compliance) (EUAMAFAK)

Keywords

• Applied energy research
• District energy simulation
• Hydrogen technology consulting
• Building performance monitoring
• Heat pump development

Headquarters

HQ city

Braunschweig

HQ country

Germany

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Technology or R&D, Operations, Infrastructure, Marketing or Sales

Revenue model

1. Publicly Funded Research Projects: siz energieplus operates primarily as a research institute funded through competitive public research grants. Funding sources include the German Federal Ministry of Education and Research (BMBF), Federal Ministry for Economic Affairs and Climate Protection (BMWK), European Regional Development Fund (ERDF), Lower Saxony Ministry for Science and Culture, and the Volkswagen Foundation. Projects are typically collaborative (Verbundvorhaben) with universities, research institutes, municipalities, and industry partners.
2. Research Consulting Services: Provides consulting services in energy system planning, quality management for buildings, operational optimization, and digitalization of building processes for municipalities, public utilities, and industrial clients. Revenue is generated through contracted research and consulting engagements.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels5 records

Core offering

siz energieplus is an An-Institut (affiliated institute) of TU Braunschweig operating within the Steinbeis network. It conducts applied research and provides consulting on sustainable, cross-sector energy concepts for buildings, districts, and cities. The institute develops open-source simulation tools for district energy planning, performs technical monitoring and quality management for buildings, and pioneers hydrogen technologies and heat pump systems research.

Product overview

Siz energieplus is a research institute (Steinbeis Innovationszentrum) affiliated with the Technical University of Braunschweig. They develop and provide simulation and design software tools for sustainable energy planning in buildings and urban districts. Their core software products include QuaSi (district simulation), GenSim (thermal building simulation), Sodele (PV yield simulation), ReSiE (district energy supply simulation in Julia), and WPSOURCE (heat pump pre-design tool). These tools are available as open-source software and are integrated into commercial BIM tools such as the Building Configurator by Digital Building Industries (DBI). Their research focuses on buildings and neighborhoods, quality management, digitization, cross-cutting energy issues, technologies (heat pumps, geothermal, energy storage, electrolysis, fuel cells), and networking.

Differentiator

Problem solved

Functional benefit

Products and services

• Applied Research and Consulting on Sustainable Energy Concepts

Quantifiable outcome

• Efficiency increase of electrolysis from ~55% to up to 90% through heat integration in the P2G&H approach (Klimaquartier Neue Weststadt Esslingen)
• +4 more outcomes

Named customers15 records

Segments4 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Partnerships

49 partnerships are on record, tiered core, major and minor.

• Technische Universität Braunschweig (TU Braunschweig)coreStrategic or Co-development Partner · 1 October 2024siz energieplus is an affiliated institute (An-Institut) of TU Braunschweig. The two entities collaborate extensively in research projects including H2-Terminal Braunschweig (with 7 TU institutes), TEN.efzn (with Institut für Thermodynamik and ISFH), and multiple EnOB/EnEff projects. The partnership enables academic rigor combined with practical implementation.
• Institut für Thermodynamik (IfT), TU BraunschweigcoreStrategic or Co-development Partner · 1 October 2024Collaboration within TEN.efzn — IfT conceptualizes novel heat pump technology while siz energieplus handles requirement-compliant integration of plug-and-play concepts into building heating and hot water systems.
• Institut für Solarenergieforschung (ISFH)coreStrategic or Co-development Partner · 1 October 2024Partner in TEN.efzn focused on AI-based control devices for optimizing operating strategies and error detection for heat pump systems.
• University of HamburgcoreStrategic or Co-development Partner · 1 September 2022Participating university in H2-Terminal Braunschweig project (Institute for Physical Chemistry: aging diagnostics of electrolysers) and in ReAEL250 and ECatWErecovery projects, where experimental work is conducted at Hydrogen Terminal Braunschweig.
• Digital Building Industries AG (DBI)coreTechnology or Integration · 1 April 2022Joint partner in QuaSi_II project. DBI integrates the open-source simulation tools (QuaSi, GenSim, Sodele, ReSiE) into its web-based BIM tool 'Building Configurator'. The tools are published as open-source software.
• Enapter (AEM Multicore Electrolyser)coreTechnology or Integration · 1 November 2020Supplier of the AEM Multicore Electrolyser (1 megawatt power class) — the world's first prototype bringing AEM (Anion Exchange Membrane) technology to megawatt scale — installed at the H2-Terminal Braunschweig research facility.
• Fraunhofer-Gesellschaft (multiple institutes)coreStrategic or Co-development Partner · 1 November 2020Multiple Fraunhofer institutes participate in siz energieplus projects: Fraunhofer ZESS (Energy Storage), Fraunhofer IFAM, Fraunhofer ICT, Fraunhofer ISE, and Fraunhofer IWES in projects including H2-Terminal, hyBit, TEN.efzn, and EVer-VRFB.
• German Research Center for Artificial Intelligence (DFKI)coreStrategic or Co-development Partner · 1 November 2020Research partner in hyBit project, collaborating with siz energieplus on multi-criteria scenario design for complex energy and material flow systems in the context of the Bremen H2 hub.
• OFFIS e.V.coreStrategic or Co-development Partner · 1 November 2020Research partner in hyBit project, contributing to the transformation platform and socio-technical transformation of industrial centers.
• University of BremencoreStrategic or Co-development Partner · 1 November 2020Lead partner in hyBit project. Collaborates with siz energieplus on developing the concept for a sustainable, CO2-neutral, and resilient H2 hub in Bremen and on multi-criteria scenario design.
• swb Erzeugung AG & Co. KGmajorStrategic or Co-development Partner · 1 November 2020Utility partner in hyBit project for Bremen's industrial hydrogen transformation, contributing to energy generation and supply infrastructure.
• Wesernetz Bremen GmbHmajorStrategic or Co-development Partner · 1 November 2020Grid operator partner in hyBit project, contributing to hydrogen distribution infrastructure planning.
• ArcelorMittal Bremen GmbHmajorStrategic or Co-development Partner · 1 November 2020Industrial partner in hyBit project, representing Bremen's heavy industry sector and potential hydrogen offtake for defossilization.
• Stadt EsslingencoreStrategic or Co-development PartnerMunicipal partner and host city for the Klimaquartier Neue Weststadt Esslingen — Germany's first climate-neutral hydrogen quarter, where siz energieplus developed the innovative energy supply concept based on P2G&H approach.
• Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW)coreStrategic or Co-development PartnerResearch partner in Klimaquartier Neue Weststadt Esslingen project, contributing expertise in solar energy and hydrogen technologies.
• Green Hydrogen Esslingen GmbHcoreStrategic or Co-development PartnerIndustry partner in Klimaquartier Neue Weststadt Esslingen for the development and operation of the green hydrogen production facility.
• Stadtwerke Esslingen GmbH & Co. KGmajorStrategic or Co-development PartnerMunicipal utility partner in H2-Quartier project, examining Power-to-Gas&Heat approach for urban energy supply.
• Stadtwerke Winnenden GmbH & Co. KGmajorStrategic or Co-development PartnerMunicipal utility partner in H2-Quartier project, one of four districts in the Stuttgart region being studied for P2G&H-based climate-neutral energy supply.
• Stadt Freiburg im BreisgaumajorStrategic or Co-development PartnerCity partner in H2-Quartier project, examining the Dietenbach district for P2G&H-based climate-neutral energy supply, alongside four districts in Stuttgart.
• LBBW Immobilien Kommunalentwicklung GmbHmajorStrategic or Co-development PartnerReal estate development partner in H2-Quartier project, contributing to the urban development and implementation aspects of climate-neutral districts.
• Stadtwerke Wertheim GmbHmajorStrategic or Co-development PartnerMunicipal utility partner in H2-Quartier project for the towns of Wertheim and Bad Mergentheim in Main-Tauber district.
• Stadtwerke Tauberfranken GmbHmajorStrategic or Co-development PartnerMunicipal utility partner in H2-Quartier project, examining P2G&H approach for climate-neutral energy supply in the Main-Tauber district.
• TU Bergakademie FreibergcoreStrategic or Co-development PartnerResearch partner in ReaKT project (resilient energy concepts for building heat and cooling supply), contributing expertise in technical thermodynamics.
• DBI Gas- und Umwelttechnik GmbHcoreStrategic or Co-development PartnerPartner in ReaKT project and QuaSi_II project, providing expertise in energy supply systems and BIM tool integration.
• Deutsche Institut für Normung e.V. (DIN)coreStrategic or Co-development PartnerPartner in ReaKT project, working on recommendations for adapting technical standards and guidelines to future climate and energy conditions.
• ZAE Bayern e.V.coreStrategic or Co-development PartnerResearch partner in EVer-VRFB project, working on thermal management and outcome & dissemination for Vanadium Redox Flow Batteries.
• Bundesverband Energiespeicher Systeme e.V.minorStrategic or Co-development PartnerAlliance partner in EVer-VRFB project, representing the energy storage systems industry.
• Bundesverband Deutscher FertigbauminorStrategic or Co-development PartnerAssociation partner in EVer-VRFB project, with demonstration case at Fertighauswelt Wuppertal.
• Wärme Infrastruktur Meldorf GmbH & Co.KG (WIMeG)coreStrategic or Co-development PartnerOperator of Germany's largest ground basin heat storage (45,000 m³) in Meldorf. siz energieplus is researching the use of a novel rotation heat pump at this site in a BMBF-funded project.
• BS|ENERGY (Braunschweiger Versorgungs-AG & Co. KG)majorStrategic or Co-development PartnerMunicipal utility and cooperation partner in C2T (Connect to Transform) project for the BAHNSTADT Braunschweig (~300 ha), and in EnEff Campus projects for TU Braunschweig campus energy optimization.
• Institut für Urbanistik und Entwurfsmethodik (iSE), TU BraunschweigcoreStrategic or Co-development PartnerInstitute partner in EnEff Campus projects, C2T project, and Future space Wolfsburg project, contributing urban planning expertise.
• elenia (Institut für Hochspannungstechnik und Energiesysteme), TU BraunschweigcoreStrategic or Co-development PartnerInstitute partner in H2-Terminal Braunschweig (grid and system integration of electrolysers), EnEff Campus, and C2T projects.
• IBEA (Institut für Bauklimatik und Energie der Architektur), TU BraunschweigcoreStrategic or Co-development PartnerInstitute partner in H2-Terminal Braunschweig, contributing to climate neutrality and energy integration research.
• InES (Institut für Energie- und Systemverfahrenstechnik), TU BraunschweigcoreStrategic or Co-development PartnerInstitute partner in H2-Terminal Braunschweig, focused on dynamic simulation of electrolysers.
• ivb (Institut für Verbrennungskraftmaschinen und Brennstoffzellen), TU BraunschweigcoreStrategic or Co-development PartnerInstitute partner in H2-Terminal Braunschweig, working on fuel cell systems and drives.
• iWF (Institut für Werkzeugmaschinen und Fertigungstechnik), TU BraunschweigcoreStrategic or Co-development PartnerInstitute partner in H2-Terminal Braunschweig, contributing to overall system modeling and holistic evaluation.
• Institut für Thermodynamik (IfT), TU BraunschweigcoreStrategic or Co-development PartnerPart of TEN.efzn, conceptualizing novel heat pump technology (up to 200°C) and modular plug-and-play heat pump modules for buildings.
• Institut für Elektrische Maschinen, Antriebe und Bahnen (IMAB), TU BraunschweigcoreStrategic or Co-development PartnerPart of TEN.efzn, developing and researching the power electronics for integrating heat pump modules into future electrical energy systems.
• Wuppertal Institut für Klima, Umwelt, Energie gGmbHmajorStrategic or Co-development PartnerResearch partner in hyBit project, contributing to climate protection, energy, and mobility research for Bremen's hydrogen economy transformation.
• Hamburgisches WeltWirtschaftsInstitut (HWWI) gGmbHmajorStrategic or Co-development PartnerResearch partner in hyBit project, contributing economic research for networking with North & Baltic Sea region partners.
• Freie Hansestadt BremenmajorStrategic or Co-development PartnerMunicipal partner in hyBit project, with Senator for Science and Ports involved as a key stakeholder in Bremen's hydrogen hub development.
• Lehrstuhl für Software Engineering, RWTH AachencoreStrategic or Co-development PartnerAcademic partner in C2T project, contributing software engineering expertise for the C2T platform development.
• Lehrstuhl für Arbeits-, Organisations- und Sozialpsychologie (AOS), TU BraunschweigcoreStrategic or Co-development PartnerResearch partner in C2T project, contributing organizational psychology expertise for smart city implementation.
• Technische Universität Braunschweig, Institut für Siedlungswasserwirtschaft (ISWW)coreStrategic or Co-development PartnerVerbundkoordination (project coordination) partner in ReNexValue project. Jointly developing modular process chain for sustainable water treatment for hydrogen production.
• Abwasserverband Braunschweig (AVB)majorStrategic or Co-development PartnerPartner in ReNexValue project, providing wastewater infrastructure for the pilot plant operation at Klärwerk Steinhof in Braunschweig.
• Ebner GmbH & Co. KGmajorStrategic or Co-development PartnerIndustrial partner in ReNexValue project, providing industrial wastewater for the pilot plant operation.
• EnviroChemie GmbHmajorStrategic or Co-development PartnerIndustrial partner in ReNexValue project, contributing environmental engineering expertise for water treatment processes.
• Stadtentwässerung Braunschweig GmbH (SE|BS)minorStrategic or Co-development PartnerPartner in ReNexValue project, contributing to wastewater treatment infrastructure and circular economy aspects.
• Industriewasserversorgungsgesellschaft Nordwest-Niedersachsen mbH (iwag)minorStrategic or Co-development PartnerPartner in ReNexValue project for industrial water supply and treatment.

Scale indicators10 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Fraunhofer ISE: Germany's leading applied research institute for solar energy and building energy systems, including heat pumps, hydrogen production, and district energy. Like siz energieplus, it competes for the same BMBF/BMWK research funding and serves municipalities on Energiewende projects, but at much larger scale.
• Wuppertal Institut für Klima, Umwelt, Energie: Applied research institute for climate, environment, and energy with strong municipal-decision-support and Energiewende consulting practice. Joint partner in hyBit and a direct comparator for federal research grants targeting energy transformation.
• Fraunhofer IWES: Fraunhofer institute focused on wind energy, hydrogen, and integrated energy systems. Active in the same research consortia as siz energieplus (e.g., hyBit, H2-Terminal) and competes for related federal hydrogen grants targeting industrial and district decarbonisation.
• IZES gGmbH: Non-university research institute in Saarbrücken focused on renewable energy systems, energy transition, and sustainability consulting. Overlapping mandate in applied research for municipalities and utilities with significant BMBF/project funding overlap.
• EIFER – European Institute for Energy Research: Joint research institute of EDF and KIT focused on distributed energy systems, hydrogen, and energy-efficient communities. Closely comparable in size, mission, and applied-research methodology to siz energieplus.
• Öko-Institut e.V. Independent applied research institute for sustainability and future-viable energy systems. Partner in the hyBit consortium with siz energieplus, and competing for federal research funding on hydrogen, sector coupling, and climate-neutral building energy.
• ifeu – Institut für Energie- und Umweltforschung Heidelberg: Research institute focused on energy and environmental research with sustained funding from BMBF, EU, and corporate clients. Overlaps with siz energieplus on district energy, mobility, and hydrogen transition consultancy for public-sector clients.

Others

• VDI/VDE Innovation + Technik GmbH: Project management agency supporting federal/state ministries on research funding programmes; not a direct research competitor but acts as a key interface for funding channels that siz energieplus and its direct peers bid into.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/siz-energieplus

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 records

Funding overview

Funding rounds

Investors

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M&A

Investments

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Frequently asked questions about siz energieplus