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.
It is renewable in the sense that given infinite time, you can use it to grow infinite energy (for the nitpickers: assuming an eternal sun).
It is not infinite though and the amount of power you can extract from it is limited but that's true for every renewable sources: you have a limited amount of places where you can put dams, where you can put windmills or even solar panels.
What is important is that it is not power generation that consumes a scarce good (as fossil power does) but that it is increases in power generation that consumes it, in a reversible way.
Sorry I don't have it handy, just read it, probably on /r/askscience a while ago. A quick search indicate that maybe this is not as true as I thought. That seems to be the case mostly for coal and for some forms of oil, but not all of it.
@Mihies@gandalf_der_12te Yes it is. The waste from biomass can be used as fertiliser for new plants, so a circle is formed. One tree is not quite the right model, you could think instead about managed forests where older growth is harvested and new growth is always in various stages, from saplings to ‘ready next year’. Carbon from the biomass process is used by the new growth.
Wood is a material that's made from carbon that has been extracted from the atmosphere using an organic process.
You can make buildings and furniture out of wood and you're sequestering carbon while having a nice place to live and some nice furniture.
You can also burn the wood for heat energy. This releases the carbon into the atmosphere, but the tree that got cut down makes space for a new tree to grow. When that new tree grows it pulls out the carbon that was added by burning the wood. So it's carbon neutral.
Renewable doesn't mean it's instantly replaced. It means there's a well understood process to replace it. It's not popular among those that hate the lumber industry, but it's one of the more environmentally friendly options considering global warming. Consider how trees used for building means using carbon extracted from the air for building things. Even burning wood is carbon neutral, so it's better than most heating options.
Sure, that's all nice. However at what scale is that sustainable? Also burning wood yields all sorts of fine particles, not just CO2, which are not good for humans. Plus we are reducing forests at global level. Can you imagine the forest area for providing power to a whole city?
Wood wouldn't be a good option for powering a city, obviously. Neither is coal though.
Global warming isn't going to be solved by a single solution. Wood makes sense for building materials and for heating in rural areas. It's not going to be good for producing electricity, but fortunately there's other technology for that.
Yes, however the article lists it as a power source (of course it's great for building if possible) hence I'm looking at that aspect only. It's more suitable for heating, however, again, at scale it would be problematic (at that's not even a big one) plus emissions are not healthy. If you ignore emissions and use it for heating of few areas here and there (like it is a trend with pellets), taking into account growth rate, it could be a renewable I suppose.
The deforestation of the Amazon is largely driven by a desire for more land to grow biofuels (sugarcane) on.
The byproducts of sugar production (the leaves and stalks) are used to produce ethanol from a biological, renewable source, as opposed to fossil fuels.
Oh, and in the Amazon, said sugarcane farming is often done by slaves.
You either need more farmland to grow what will become biofuels on it, or you have to stop growing food on existing farmland, which means food gets more expensive.