Everyone using the same split doesn't make the split non-arbitrary. Aren't small-scale hydro and large-scale hydro rather different things? Is large-scale hydro really "renewable", given that reservoirs fill with sediment, and their creation leads to lots of CO2 being released? Why is nuclear power "non-renewable"? It's renewable on any reasonable time scale, and doesn't produce CO2 during operation. Surely photovoltaic and thermal solar power are rather different technologies?