There is an increasing interest in new energy sources, intended to replace fossil fuels like gas and oil.
There are two main reasons why fossil fuels are to be replaced, at least in part:
- they are going to end, eventually
- we produce a CO2 when we use them
These two problems are quite connected, but they are different. When we talk about renewables, we usually mean solutions that satisfy both requirements: being infinite and not producing CO2 when used (therefore clean).
For example, solar energy is infinite and clean. The same holds for wind, and hydro power, or geothermal power.
Nuclear power plants, instead, do NOT produce and CO2, but their fuel is not infinite.
There is another energy source that is usually not considered but turns out to be quite interesting, at least in some areas: wood. Let's see why.
First of all, what does a wood-powered power plant look like?
Basically, there is some processing of the wood (harvested and collected in nearby forests) that converts it in some kind of gas. This gas is then burned in some regular internal combustion engine, and electrical energy is produced. Is this a eco-friendly energy source?
1. Wood is infinite
Well, of course it is not infinite in the sense that we can collect any amount of it. It is infinite in the sense that it is renewable. In other words, if we collect a reasonable amount of wood and following some well-knows schedules and protocols, then trees will grow in the forest to compensate the trees that we have removed, in a perfectly renewable cycle. This is already done extensively in some parts of Germany and Austria, for example. People there cut tree continuously, every year, and the size of the forest stays the same, because new trees replace the missing ones.
2. Burning wood does not produce CO2
This statement deserves some explanation. Burning wood DOES produce CO2, of course. Burning any fuel produces CO2. However, the amount of CO2 that is produced when a tree is burnt is exactly the same amount of CO2 that the tree consumed when growing. Therefore the net amount of CO2 is zero.
This is great news! It means that if a power plant is powered by wood coming from forests that keep the same size (because tree cutting is done in a smart and sustainable way), then we will have free energy from a renewable source and without producing CO2 in the air.
The main disadvantage of this method is that it is not possible to apply it everywhere. Only in some places there is enough wood to produce the energy required by people living there. Austria is a notable example for this. Some other places in the world (including part of the US) are probably extremely good candidates for this solution too.