We investigate whether PV can effectively and economically contribute to a massively renewable energy (RE) power generation future for Switzerland. Taking advantage of the country’s flexible hydropower resources, we determine the optimum PV/battery configurations that can meet the country’s growing electrical demand firmly 24×365 at the least possible cost while entirely phasing out nuclear power generation. We examine several ultra-high RE scenarios where PV and hydro would meet the bulk of the country’s demand. Depending on future cost predictions for PV and batteries, and a small contribution from domestic or imported dispatchable resources, we show that power production costs on the Swiss grid would range from 6 to 10 US cents per kWh. This is well in line with current market prices on the regional TSOs.