Geothermal has its own shares of risks (crossing waterways in the ground can lead to contamination and the drilling can cause earthquakes, http://www.deutschlandfunk.de/erdwaerme-in-deutschland-erdbe...), and biomass fouling towers look ugly, stink and the cow manure (or whatever is to be used as fuel) has to be transported.
Geothermal and biomass are also weather-independent, in addition to the long-term drought possibility that justinator mentioned.