Singapore is betting on floating solar farms and vertical panels to increase its clean-energy supplies and cut carbon emissions, a model that could work in other densely populated cities, urban experts said.With renewable energy options such as wind, hydro, nuclear and biomass ruled out, solar photovoltaic (PV) is the most viable option for Singapore, despite limited land for large-scale farms, and challenges such as frequent cloud cover.Last month, Singapore inaugurated a 5 megawatt offshore…