| dc.description.abstract | The effects of floating photovoltaic (PV) installations on the hydrodynamics and the ecodynamics
of a coastal sea as the North Sea are analysed, with a coupled physical-biogeochemical 1D
column model (GOTM-ERSEM-BFM). The model is calibrated and validated with the use of
Smartbuoy observations from three locations in the North Sea. The equations of the model are
altered as to include four different effects (ef) of the PV installations, namely: ef1) decreased
light conditions due to the shadowing effect of the platforms, ef2) reduced wind stress due to
the limitation of the free surface of the water column, ef3) introduction of an additional surface
stress experienced by currents, due to friction induced by the platforms, ef4) reduced wave
height due to the presence of the platforms. The 1D model is capable of reproducing the main
seasonal patterns of ecosystem variables such as chlorophyll a, with performance comparable
to a 3D model. Moreover, it proves to be more efficient in open-sea locations where horizontal
advection is of less importance. Regarding the individual effects, ef1 is the dominant one.
However, some ecosystems may reveal resilience to ef1 for small percentages of coverage. The
effect of ef2 on the hydrodynamics and the ecosystem is small in locations with strong tidal
currents. This effect can be very important for stratified locations due to its impact on the top
mixed layer and thus on primary production. The ef3 can be important for the ecosystem of
locations with strong currents. This is evident for small percentages of coverage where ef3 leads
to a minimum of suspended sediment near the surface (and maximum of irradiance). The ef4
reduces strongly the concentration of suspended sediment in the water column. However, the
reduction occurs mainly at lower depths and out of the photic zone, leading to no significant
changes in the light availability of the ecosystem. Overall, the shadowing effect (ef1) of the
platforms on the ecosystem is the most important. However, for the case of well mixed locations
with high concentration of suspended sediment near the surface, ef1 is partly compensated by
the effect of reduced turbidity that follows the other three effects. This is more prominent for
small percentages of coverage where ef3 is of comparable importance to ef1, resulting in no
significant overall impact of the PV installations on the marine ecosystem. Concluding, well
mixed locations with high currents and large concentration of suspended sediment near the
surface are more favorable to the installation of a solar power plant. However, this statement
is restricted by the assumption that the power plant will not occupy more than 20% of the 1D
domain. | |
