Q&A with Dr. Holger Neuhaus (Fraunhofer ISE)
Short bio: Dirk Holger Neuhaus holds a PhD from the University of New South Wales. He was a development engineer at Pacific Solar Pty Ltd. He worked more than 15 years for Solarworld AG, initially responsible for quality assurance and technology in cell production, later heading the global R&D activities along the entire value chain. In 2018, he joined Fraunhofer ISE to lead Module Technology.
Question 1: Fraunhofer ISE recently updated its website to emphasize the importance of integrated PV. What role can integrated-PV play in the Energy transition in Germany and Europe in General?
Germany committed itself to increase the share of renewable energy generation from renewable sources to at least 80% by 2050. In almost all future scenarios, photovoltaics will play a major role. From a study published by Fraunhofer ISE earlier this year, we can see that up to 500 GW of installed photovoltaics will need to be installed in Germany to achieve our sustainability goals.
By the middle of 2019, 48 GW of photovoltaics had been installed in Germany, with about 75 % on roofs and the rest in free-standing plants. The total installed power must therefore be increased by up to 10 times to achieve the energy transformation. It can be foreseen that massive further expansion of free-standing plants would lead to conflicts and acceptance problems. By integrating PV technology into building envelopes, car surfaces, roadways, railways and noise barriers, and combining them with agricultural and surface-water areas, enormous areas which are already used for other purposes can also be exploited for generation of solar electricity. Integrated photovoltaic technology thus solves not only land-use conflicts but also results in positive synergistic effects in many cases.
In a recent study, we analysed the technical potential for integrated photovoltaics in Germany. If all areas would be used, we could install 3.400 GW of integrated PV in Germany. This is a very encouraging number considering the fact that only 500 GW of PV are required for the sustainable transition of our entire energy supply system. Product development for this transition is what we aim to exploit at Fraunhofer ISE, jointly with applied research.
Question 2: How does the HighLite project relate to the opportunities and challenges with integrated PV?
The integration of PV in existing structures requires material and process development to create these new multi-functional materials. Within the HighLite project, we focus on the development of new module designs and products for building-applied, building-integrated and vehicle-integrated photovoltaics.
The biggest challenge for building-integrated photovoltaics, which covers façade and roof tile modules, is to achieve high customer acceptance, for instance through colour coatings and simple installation while maintaining high module efficiencies. A further requirement is the weight reduction of façade modules.
For vehicle-integrated photovoltaics, we have to develop new modules with 3-dimensional curvature, and we have to find manufacturing processes suitable for high-volume manufacturing. Furthermore, vehicle-integrated photovoltaic modules are exposed to changes in shading. Further challenges such as resistance to vibration, passenger safety and road safety are also addressed.
Besides switching to renewable energies to achieve the sustainability targets, it is equally important to reduce the energy consumption in module manufacturing along the entire value und supply chain. The reduction of the energy consumption in module manufacturing and the reduction of related CO2 emissions are therefore main development targets within Highlite as well.
Question 3: What innovations is Fraunhofer ISE bringing to the HighLite project?
Fraunhofer ISE has already since a long time a strong track record in the development of crystalline silicon solar cells and modules. Our pilot lines are very close to industrial production, allowing a fast transfer from process development to industrial manufacturing. Fraunhofer ISE further supports the development with its accredited facilities for cell and module calibration and reliability testing.
In the field of cell development, Fraunhofer ISE will contribute its highly efficient TOPCon technology. In the field of module development, Fraunhofer ISE will bring in its process, material and equipment expertise for cell-cutting, shingling and encapsulation.
A major focus of Fraunhofer ISE within HighLite will be the product development in building-applied, building-integrated and vehicle-integrated photovoltaics. Fraunhofer ISE has recently developed a spherically curved solar car roof, whose highly efficient solar cells deliver an output of around 210 W/m². Due to the overlapping shingle interconnection technology, the module surface can be used to a maximum for power generation and offers a homogeneous, aesthetic overall picture. Within HighLite, Fraunhofer ISE is investigating glass-free modules for lightweight car applications. Fraunhofer ISE will contribute with its expertise on module design, shingling, new materials, encapsulation, testing and thermo-mechanical and electrical simulations.
Question 4: How do you see the development of VIPV in coming years?
It is a good time to develop concepts for the integration of photovoltaics into vehicles, because all large manufacturers are shifting towards fully electric cars. Important parts of the electric infrastructure are already part of the car. The integration of photovoltaics supports e-vehicles by offering a significant cruising range extension as well as a significant reduction of CO2 emissions. After the presentation of the vehicle- integrated PV concepts by new start-ups such as SonoMotors and Lightyear, there has been a strong shift in the automotive industry to now seriously consider the integration of photovoltaics into the car surface.
Yet, the large-scale PV integration in the vehicle outer shell with direct connection of the PV power to the car battery has so far been limited to prototypes. In the coming years, prototypes for all parts of the car body will be developed. These prototypes will improve in aesthetics, power output, safety, reliability and manufacturing cost. The leap from prototypes to high-volume manufacturing will reduce cost dramatically in the next years.
Within HighLite, new prototypes for the car hood, sides and boot will be developed and tested. To develop the technology as close to the market as possible, the work on different solutions will be advised by an industrial partner who is due to join the project in the form of a subcontractor. The valuable expertise of this subcontractor will contribute to the development of the module technology in agreement with the norms and regulations of the automotive industry and support the prototype development for an electric vehicle.
Question 5: How will HighLite help to re-establish PV production in Europe?
Over the last years, a lot of high-volume PV manufacturing moved from Europe to Asia. Fraunhofer ISE performed a study to analyse the reason for this development. These days, the access to capital is the main driver for this development, since there is no significant difference in manufacturing cost between Europe and Asia if the same factory sizes are compared. Consequently, there is a good perspective to re-establish high-volume manufacturing in Europe. These days, module manufacturing is already expanding its production capacities in Europe again.
Factories for manufacturing integrated photovoltaic products will produce much smaller volumes than production facilities for standard modules. The products are customized with a large variation of products manufactured on one line. The close coordination with the customer becomes very important. All these factors will make it very attractive to invest in factories for integrated photovoltaics in Europe. There is therefore a great likelihood that product development from the HighLite project will help to re-establish PV manufacturing in Europe.