ABSTRACT
Photovoltaics (PV) play a major role in Switzerland’s energy transition. Compared to conventional installations in urbanized areas, PV at high altitudes may yield a 30% increase in power generation due to stronger solar irradiation and lower module temperatures as well as a considerably higher production share in winter. Numerous Swiss hydropower reservoirs are situated above 1,000ma.s.l. and already offer a good accessibility and grid connection. Therefore, they could provide an ideal base infrastructure for the installation of PV. The two main options for PV operation at reservoirs include modules mounted to the dam structure and modules floating on the reservoir.
This study investigates 23 selected Swiss hydropower reservoirs with 26 dams at elevations between 1,200 and 2,500m a.s.l. regarding their power production potential. The developed work-flow comprises a GIS analysis including inter-daily as well as seasonal shading effects. The resulting electricity production from solar radiation impinging on a PV module installed at a given orientation and tilt are simulated using the software SUNWELL. For validation, the simulated electricity production at selected sites is compared to planned or recently installed PV plants. The study ranks the investigated sites according to a multicriteria assessment matrix considering societal acceptance, energy yield and economic feasibility. The estimated total electricity production at the investigated sites amounts to 11.5 to 14.5 GWh/a for dam-mounted PV and 370 to 490 GWh/a for floating PV. The developed work-flow may also be applied to assess other promising PV installation sites.
