Renewable Energy has many parts, and some of them can do jobs that others cannot do. It is important to work together to bring the best renewable Energy to the world that we can hope to achieve.
This diagram represents a short overview over different elements of a renewable energy network, and what the different parts can do, and what not.
For example, Hydropower can be both an energy source (flowing water through a turbine) but also a means of energy storage (by keeping the water behind the dam). Renewable Biomass can be stored well, but can also be turned into a renewable source of energy. Batteries can store energy well, but cannot produce energy.
Thoughts, comments, likes :-)
Nah it's friction from rocks banging into each other when the Earth was being formed. The surface of the Earth cooled down, but you dig down deep enough it gets really hot. Hot enough to melt rocks, or as the pros call it... "magma". Dump some water down there and you get steam and you can drive a turbine with that steam. Though actual geothermal energy implementations are probably a little more complicated than that. But that's the gist of it.
Well, Wikipedia claims
In that sense, it's the only renewable energy source we have that's not indirectly powered by the sun. It's most similar to (proper) nuclear power, but the latter isn't "renewable" because it requires digging up fuel from the crust.