Fraunhofer Institute for Solar Energy Systems ISE

Tandem Photovoltaics –
The Road to Higher Conversion Efficiencies

Our research aim is to increase the energy conversion efficiency of photovoltaics and bring down the costs. Tandem photovoltaics holds great promise for achieving these goals and is among the fastest-developing solar technologies today.

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Heat Pumps –
A Key Technology for the Energy Transition

Heat pumps will be the dominant heating technology in the future energy system. Scientific studies have shown they will play a key role in reducing greenhouse gas emissions in the building sector. Today heat pumps are used in numerous types of buildings.

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Paths to a Climate-Neutral Energy System

The German Energy Transition in its Social Context
Study from Fraunhofer ISE | February 2020

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Integrated Photovoltaics – Areas for the Energy Transformation

Integrating PV technology into building envelopes, vehicles and roads, as well as over agricultural fields and floating on water surfaces, capitalizes on surface areas with a tremendous potential for generating solar power.

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Digitalization: The Enabler and Driver of the Energy Transition

In the future energy system, digitalization is key for decentralization and flexibility as well as achieving energy and resource efficiency.

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Photovoltaics is a central pillar of the future energy supply from both an economical and ecological point of view.

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Energy Efficient Buildings

Energy efficiency in buildings plays a central role in climate protection. Currently the building sector in Germany is responsible for over 40% of the final energy demand.

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Solar Thermal Power Plants and Industrial Processes

Already today, concentrating solar thermal power plants (CSP) coupled with large thermal storage units provide dispatchable renewable electricity. Such systems show great potential for industrial systems, increasing efficiency and allowing more flexibility in the energy flows.

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Hydrogen Technologies and Electrical Energy Storage

Our R&D services address the generation, conversion and further thermo-chemical processing of hydrogen. In electrical energy storage, we offer R&D along the entire value chain: from materials, through the cell and module up to the complete battery system.

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Power Electronics, Grids and Smart Systems

We are working to optimize the interplay between efficient renewable energy generation, the security of supply, energy storage and stable grid operation.

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Dear customers, project partners, sponsors and friends,

Unfortunately, the COVID 19 pandemic continues to keep the world in its grip, presenting us with major challenges and tight constraints. In Germany stricter measures to reduce contact have been put in place since January 2021.

In the new year, Fraunhofer ISE will continue to do everything in its power to protect the health of its employees and society as a whole by acting responsibly. Therefore, we strictly adhere to the official guidelines and those of the Fraunhofer-Gesellschaft and also implement measures which are specific to Fraunhofer ISE. Of course, we remain in operation and continue to serve you. We process all project orders and continue to carry out our R&D for the energy transition. Should there be unavoidable small delays in projects at times due to the measures implemented to contain the infection, we ask for your understanding. We are determined to carry out all work as consistently, quickly and reliably as the current pandemic situation allows. Our employees are working partly at the institute and partly in their home offices. Therefore, please get in touch with your contact person preferably by e-mail. Should you still have difficulties in contacting them, please call our main telephone number: +49 761 4588-0.

We wish you, your relatives and employees good health!

Warm regards,

Prof. Dr. Hans-Martin Henning
Prof. Dr. Andreas Bett

Institute Directors Fraunhofer ISE

R&D for Energy Transition

The Fraunhofer Institute for Solar Energy Systems ISE creates the technological foundations for supplying energy efficiently and on an environmentally sound basis in industrialized, threshold and developing countries. With its research focusing on energy conversion, energy efficiency, energy distribution and energy storage, it contributes to the broad application of new technology.

Fraunhofer ISE develops materials, components, systems and processes in five business areas. In addition to its R&D, the institute offers testing and certification procedures. Furthermore, it features an excellent laboratory infrastructure and is certified according to the quality management standard, DIN EN ISO 9001:2015. Founded in 1981, Fraunhofer ISE, with a staff of over 1200, is the largest solar research institute in Europe.

Current Press Releases


Press Release #2 / 22.2.2021

Dual Yield on Arable Land: Guideline for Agrivoltaics Published

Photovoltaic modules, which are mounted on a structure, generate renewable electricity and underneath agricultural crops grow. A new guideline provides up-to-date information on the technology, its potential and the current state of development. 


Press Release #1 / 25.1.2021

Fraunhofer ISE develops highly compact inverter for direct connection to medium-voltage grid

Researchers at the Fraunhofer ISE, together with partners, have developed and successfully commissioned a highly comptact inverter for direct feeding into the medium-voltage grid.




Press Release #31 / 11.12.2020

Ensuring Medical Care in Crises and Emergencies

Six of the Fraunhofer-Gesellschaft’s institutes have joined forces under the lead management of the Fraunhofer IFF in Magdeburg and are developing an integrated system for mobile, distributed medical care in the Demo-medVer project. 


Press Release #30 / 12.11.2020

Material Analysis for the Global Energy Transition

Against the background of the global energy transition, the development of new technologies and characterization methods for thermochemical and electrochemical systems is becoming more significant. Fraunhofer ISE now operates one of the few facilities worldwide for High Temperature Near-Ambient Pressure X-ray Photoelectron Spectroscopy (HT-NAP-XPS). 

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News and Events


Trade Fairs, Conferences and Workshops


Experimental Validation of a Simulation Tool to Model Photonic Effects on Upconversion – published in Nature Communications

Photon upconversion, the conversion of low-energy into higher-energy photons, has gained much interest in the fields of materials chemistry and physics. However, an adequate theoretical framework to optimize photonic structure designs for upconversion enhancement has been lacking. Researchers from Fraunhofer ISE have developed a comprehensive simulation tool to model photonic effects on upconversion dynamics. In an international cooperation with R&D groups from Stanford University, the Karlsruhe Institute of Technology (KIT) and Aarhus University, they now reached an experimental validation of the modeling framework and published their work in Nature Communications.
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Public Net Electricity Generation in Germany 2020: Share from Renewables Exceeds 50 percent

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE have presented the latest figures on the annual electricity generation in Germany. The share of renewables in the net electricity generation (the amount coming from the socket) has exceeded 50 percent for the first time, rising from 46 percent in 2019. Electricity production by wind was again the most important source, with a share of 27 percent. Together, the generation from wind and photovoltaics (183 TWh) surpassed fossil fuels (178 TWh) for the first time.
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Dr. Marek Miara Joins Board of European Heat Pump Association EHPA

Following recent EU energy policy development calling for a massive deployment of heat pumps in Europe in the years to come, the European Heat Pump Association (EHPA) appointed a new extended board to represent the industry from 2020 to 2022. Dr. Marek Miara, Business Developer Heat Pumps at the Fraunhofer Institute for Solar Energy Systems ISE, has now joined the board. He was appointed based on his scientific background in heat pump research and development and on his past involvement in the EHPA.
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Dr. Matthias Vetter receives Global Excellence Award by Energy and Environment Foundation

The Energy and Environment Foundation, India, is organizing jointly the Virtual 4th World Water Summit 2020 and the Virtual 11th World Renewable Energy Technology Congress from December 15 to 16. Coinciding with the conference, the annual »Energy And Environment Foundation Excellence Awards« will be presented to outstanding and distinguished energy personalities in the environment and energy sector to serve as a tribute to the awardee’s professionalism and commitment to demonstrate excellence in the fields of Water and Renewable Energy. Dr. Matthias Vetter, Head of Department Electrical Energy Storage at Fraunhofer ISE, has received the award in the category »Renewable Energy Sector«.
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New Articles on Innovation4E:


Does a house have to be renovated first in order to install a heat pump?

Episode 3 of a series on heat pumps in existing buildings Clearly, the less energy needed to create a comfortable indoor climate, the better. That’s why renovation measures to reduce heating energy demand always make sense. This applies to all heating systems, not just heat pumps. For various reasons, (full) refurbishment of buildings is sometimes [...]
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Are heat pumps able to deliver sufficiently high temperatures in the heating circuit?

Episode 2 of heat pumps in existing buildings: Why the maximum required temperature is not the decisive factor  When discussing the possible use of heat pumps in existing buildings, the main counter-argument is the very high temperature of the heating circuit on which they are based. The argument is that this temperature would lead to [...]
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Heat pumps in existing buildings, a blog post series in 12 parts

Heat pumps are only suitable for new buildings or for buildings that have undergone an extensive energetical refurbishment! This is a common view that can be considered disproved in many respects today. Fortunately, one could say, because especially the existing buildings are crucial to achieve climate neutrality in the future. Around 75 percent of residential [...]
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PV Module Power Increases with Improved Light Management

A novel system of optical elements redirects light so that the irradiance on the cells is increased, no light passes the pv module “unused” and more power is generated. An important goal of PV module development is to convert as much light as possible into electrical power and to reduce losses from reflection and absorption. [...]
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Scientific Blog of Fraunhofer ISE


We want to share our expertise with you. The scientific blog of Fraunhofer ISE  »Innovation4E« offers a platform for information and exchange.