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Institute of Solar Research in Almería, we are currently looking for a
Masters Student Computer Science, Engineering or similar (f/m/x) – Nowcasting application to reduce the impact of irradiance ramps on PV plants
Background: The fluctuating nature of solar irradiance causes fast changes in the power production of PV plants. Due to the higher penetration of variable renewable energy systems in the electricity grid, regulations for connecting and operating PV plants might get more restrictive. One aspect in the related grid codes are limitations of ramp rates during short term irradiance fluctuations. These fluctuations are triggered by passing cloud shadows. Positive ramp rates (increase in power) can be limited by the inverters, the critical issue are downward ramp rates. One possible and straight-forward approach to reduce ramp rates is the installation of battery storage. However, this brings along significant additional investment costs. Recent studies indicate that short-term irradiance predictions (nowcasts) are capable to provide a similar service at lower cost. In the case of downward ramp rates, a nowcasting strategy allows reducing power outputs well in advance and thus limiting the gradients. The associated loss of used power is over-balanced by the much lower costs for a nowcasting system compared to a battery storage dedicated for ramp rate mitigation. This holds especially for large scale PV plants (> 10 MW). Furthermore, the combination of a nowcasting system with a battery storage could lead to a significantly lower required capacity. Studies so far are based on ideal nowcasts. However, nowcasts go along with uncertainties. The impact of these uncertainties needs to be studied. A second aspect not addressed so far, is the option to individually controlling the inverters of sub-systems in the field. Spatially resolved irradiance nowcast are required for this purpose, which can be obtained by all sky imagers (available at DLR).
Objective of the master thesis: The aim of the master thesis project is to investigate the potential of all sky imager based nowcasts for the ramp rate reduction of large-scale PV plants. Compared to previous studies, the impact of nowcast uncertainties and the potential of spatial control in the field shall be investigated.
The following steps are foreseen:
literature research and getting familiar with the topic
preparation of a PV field model in Python (steady state performance models for the PV field can be used and have to be extended by the main dynamic effects)
definition of different control strategies using the nowcasts
validation of the PV model
simulation of different situations and evaluation of the strategies
comparison with the benchmark of a battery installation
The project is jointly supervised by DLR colleagues in Stuttgart (PV field modeling) and Almería (irradiance nowcasting)
The workplace is Almería (Spain)
A minimum period of 6 months is required
The earliest possible start date is first of April 2021
Look forward to a fulfilling job with an employer who appreciates your commitment and supports your personal and professional development. Our unique infrastructure offers you a working environment in which you have unparalleled scope to develop your creative ideas and accomplish your professional objectives. Our human resources policy places great value on a healthy family and work-life-balance as well as equal opportunities for persons of all genders (f/m/x). Individuals with disabilities will be given preferential consideration in the event their qualifications are equivalent to those of other candidates.