Fraunhofer ISE photovoltaic and inverter innovations

The energy transition is not driven by individual technologies, but by the interaction of different systems. Research institutions play a central role in this because they develop basic principles and prepare industrial applications.

Fraunhofer ISE is one of the key players in this field in Germany. As part of the Fraunhofer-Gesellschaft, the Institute for Solar Energy Systems works on solutions along the entire renewable energy value chain. The focus is on photovoltaics, power electronics and complementary technologies such as hydrogen. The aim is to make existing systems more efficient and to open up new fields of application.

Fraunhofer ISE and photovoltaic research at a glance

Fraunhofer ISE is intensively involved in the further development of solar cells and modules. The focus is not only on higher efficiencies, but also on production processes, cost structures and the use of materials. Improvements in these areas have a direct impact on the economic efficiency of photovoltaics. Another focus is on integrating the energy generated into existing grids. Solar power is generated as direct voltage, whereas alternating voltage is required in the power grid. This conversion takes place via inverters, which are among the central components of modern energy systems. Research is not limited to individual components, but looks at complete systems. This results in solutions that can be used in real applications and do not just work in the laboratory.

Inverter technology with higher voltage and less copper

One current focus of development is the design of inverters for higher voltages. Technically, a higher voltage means that less current flows for the same power. This correlation has a direct impact on the infrastructure. If less current has to be transported, cables can be designed to be thinner. This reduces the use of copper, a raw material that is in high demand as part of the energy transition. At the same time, material costs and installation costs are reduced. Inverters already work with comparatively low conversion losses. Nevertheless, the optimisation of these systems remains a key issue, as they are used in almost every photovoltaic system.

Photovoltaics in cars through integration into the car body

In addition to stationary applications, Fraunhofer ISE is also investigating mobile applications. One example is the integration of photovoltaics in vehicles. Solar cells can be integrated into components such as the bonnet, roof or rear. The aim of this approach is to generate part of the energy required directly on the vehicle. Calculations show that a significant proportion of electricity consumption can be covered with a suitable design. However, the actual effect depends heavily on the driving profile and operating conditions. This results in an additional development strand for the automotive industry. Instead of relying exclusively on external charging infrastructure, the vehicle itself becomes part of the energy system.

MorphoColor coating for coloured photovoltaic modules

Another field of research concerns the design of photovoltaic modules. With MorphoColor technology, Fraunhofer ISE has developed a coating that makes different colours possible without significantly impairing efficiency. The technical basis is a special layer on the module glass that reflects certain wavelengths of light and transmits others. This creates a colour impression, while a large proportion of the radiation can still be used to generate electricity. The most important properties of this technology can be summarised as follows:

• colourful design of photovoltaic modules
• low losses during energy generation
• Coating based on a physical process
• Use in architecture and building integration

Building integration and new requirements for photovoltaics

With the possibility of colour-matching modules, the role of photovoltaics in the construction industry is also changing. Architects and planners are increasingly demanding solutions that can be integrated into the appearance of buildings. While traditional modules are usually designed in dark colours, new coatings are opening up additional scope for design. As a result, photovoltaics is not only seen as a technical system, but also as part of the architecture. This development shows that, in addition to efficiency and costs, aesthetic requirements are also becoming increasingly important.

Classification of Fraunhofer ISE innovations in the energy system

The approaches presented illustrate the breadth of research at Fraunhofer ISE. From material development and power electronics to integration in vehicles and buildings, solutions are being developed that address different areas of the energy system. What these developments have in common is their systemic approach. Individual innovations only unfold their effect in interaction with other components. This is precisely the challenge, but also the potential of the energy transition. Fraunhofer ISE contributes to the technical realisation of these links and their transfer into applications. This gradually turns research into infrastructure that can be used in everyday life.

The Fraunhofer Institute for Solar Energy Systems ISE in Freiburg is Europe's largest research institute for solar technology. It focuses on the development of technologies for a sustainable energy supply, including photovoltaics, solar heat, hydrogen technologies and energy systems. With around 1400 employees, the institute works to increase energy efficiency and promote the use of renewable energies.