Ulf Blieske

Prof. Dr. Ulf Blieske

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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 September 2018 in IEEE Journal of Photovoltaics
Verified
Journal Article
Open access
NRNils Reiners
Nils Reiners
UBUlf Blieske
Ulf Blieske
SSSusanne Siebentritt
Susanne Siebentritt
To improve energy yield predictions and to fully understand the physical behavior of solar cells, it is necessary to investigate the effects caused by a change in the angle of incidence. All relevant angle-dependent effects are presented in this paper and angular correction factors are introduced. A new analytical model is presented, which includes internal reflection, free carrier absorption, and other parasitic absorption processes. The angular effects were exemplarily studied for the case of a very simple planar solar cell sample and a standard module sample. With an effective angle approach, the variation of the internal quantum efficiency in the standard solar module could be emulated and the results were verified with the help of a ray tracing tool developed for this purpose. The influence of the different angular factors on the current density of a standard module at an incidence angle of 70° is finally presented.

19 February 2023 in Energies
Verified
Journal Article
Open access
PDF file
EGEva-Maria Grommes
Eva-Maria Grommes
UBUlf Blieske
Ulf Blieske
JHJean-Regis HADJI-MINAGLOU
Jean-Regis HADJI-MINAGLOU
The annual yield of bifacial photovoltaic systems is highly dependent on the albedo of the underlying soil. There are currently no published data about the albedo of red soil in western Africa. In this study, the impact of the albedo of red soil in Ghana on the energy yield of bifacial photovoltaic systems is analysed. A bifacial photovoltaic simulation model is created by combining the optical view factor matrix with an electrical output simulation. For an exact simulation, the albedo of red soil at three different locations in Ghana is measured for the first time. The average albedo of every red soil is clearly determined, as well as the measurement span including instrumentation uncertainty; values between 0.175 and 0.335 were measured. Considering these data, a state-of-the-art bifacial photovoltaic system with an average of 19.8% efficient modules in northern Ghana can achieve an annual energy yield of 508.8 kWh/m2 and a bifacial gain of up to 18.3% in comparison with monofacial photovoltaic panels. To summarise, red soil in two out of three locations in Ghana shows higher albedo values than most natural ground surfaces and therefore positively impacts the annual yield of bifacial photovoltaic systems.

15 November 2021 in Journal de Physique de la SOAPHYS
Verified
Journal Article
Open access
IFIssa Faye
Issa Faye
ANAbabacar NDIAYE
Ababacar NDIAYE
UBUlf Blieske
Ulf Blieske
RGRudolph Gecke
Rudolph Gecke
DKDiouma Kobor
Diouma Kobor

4 June 2026 in Sustainability
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Journal Article
Open access
PDF file
Erisa SekimuliErisa Sekimuli
Erisa Sekimuli
Ramchandra BhandariRamchandra Bhandari
Ramchandra Bhandari
UBUlf Blieske
Ulf Blieske
As declared in the European Green Deal, the decarbonization of the EU energy system is essential for achieving Europe’s climate neutrality targets, demanding a substantial expansion of renewable energy sources and the rapid phase-out of coal and gas. It is therefore essential that newly installed PV products within the EU are designed to avoid creating additional environmental burdens due to environmental impacts during production and at the end of life (EOL) of photovoltaic (PV) modules. This study presents a life cycle assessment (LCA) of sustainable/green PV module designs in terms of recyclability using advanced high-quality recycling technologies. It compares two product systems both based on mono c-Si PV technology and the glass–glass (G–G) module design: 1. Passivated Emitter and Rear Contact (PERC) and 2. Tunnel Oxide Passivated Contact (TOPCon) cell technologies, which are assessed under production scenarios in China and Germany, and two recycling scenarios (hypothetical high-recovery recycling and partial recycling) using inventory data from eco-invent and literature sources. The results across most impact categories show that the PERC and TOPCon module designs produced in Germany with high-recovery recycling as the end-of-life strategy exhibit lower impacts than those produced in China with partial recycling as the end-of-life strategy under the adopted assumptions such as electricity mix and end-of-life modelling choices for module-only impacts (excluding BOS components). The climate change results show that TOPCon cell design under high-recovery recycling yields 10.4% lower emissions than the PERC cell design under partial recycling in Germany and 9.7% lower in China. However, both module designs emit 26.6% and 27.2% less GHG emissions when produced in Germany compared to production in China, respectively, which is line with earlier studies. With the exception of human toxicity, both PERC and TOPCon cell technologies perform better in this study than previously reported in reviewed LCA studies, reflecting the use of more recent state-of-the-art industry data concerning manufacturing requirements. The sensitivity analysis carried out on the design changes and electricity grid mix available shows that any improvements in the design process and increases in renewable energy penetration into the grid corresponds to a proportional reduction in environmental impacts across all impact categories.