Biomass: sustainable energy source?
Biomass plays an important role in making our society more sustainable. Still, the use of biomass has sparked lots of discussion for years now. Experts, politicians and scientists can simply not agree. Is biomass really as sustainable as people claim? We investigated and we will tell you what is and isn't true about biomass in this article.
What exactly is biomass?
Biomass consists of biological material such as wood, food waste or manure. It can be used as an alternative for fossil fuels, for instance to heat homes, or to replace oil and gas for the industry or to use as fuel for transport. Biomass can also serve as food for humans and livestock.
Types of biomass
There are several types of biomass, each with their own components and application:
- Wood – This type of biomass is mainly suitable as a raw material and fuel. They include (remains of) tree trunks, branches and straw.
- Arable crops – These include tuber crops, carrots and fruits. These crops are mainly used for consumption ,but the sugars, starches, oils and proteins that can be extracted from them can be used in biochemistry.
- Green biomass – This consists of grass, stalks, leaves and beet leaves, for instance. Green biomass is used in things like livestock fodder and soil enhancer.
- Algae – Algae contain a large number of valuable components such as oils, fatty acids, proteins and sugar. It can be used to manufacture things like biofuel, livestock fodder and chemicals.
- Animals from livestock breeding, fishery or hunting – This type of biomass is mainly used for human consumption, but some products (such as fat) can also be used for other purposes such as energy production.
- Waste flows – These are organic waste flows of households or industry.
Biomass can be used as food, as materials, in chemistry or energy generation. In this article, we look into the question of whether biomass is reallly a sustainble method for generating energy.
Reduce CO2 emission
The general warming of the climate is a global 'hot topic' and does not only involve politicians and activism groups, but has become a topic that is heavily discussed by every citizen. You have probably never heard the word CO2 emission as often as you have heard it over the past few years. But how does this work exactly? CO2, also called carbon dioxide, is a gas that occurs naturally in our atmosphere. This means there is nothing wrong with CO2 in itself. But just like with many other things, too much of something is never good. Due to burning coal, oil and gas to generate energy, we are emitting huge quantities of CO2. And this eventually causes problems such as the melting of polar ice caps and a global rise of the water level. Plenty of reasons to work together to reduce CO2 emissions.
Biomass as an energy source
Currently, 60 percent of all energy generated in The Netherlands is a type of biomass combustion. You read that right: the energy from biomass is generated using combustion as well. And CO2 is released while burning biomass too. However, the idea with biomass is that the CO2 that is released is captured again by growing forests or other organic material. Because it is continually 'growing back', biomass will never run out and the regrowing process removes CO2 from the air again. Plants capture carbon in their tissues and use it to create oxygen. Bio-energy which is renewable is also called 'green' energy.
Drawbacks to biomass
The discussion taking place is about the sustainability of this bio-energy. This includes the question of whether burning wood instead of fossil fuels actually helps fight climate change, or if it really just exacerbates it. When burning wood, the CO2 that was stored over decades is released all at once. Also, entire forests have to be cut down for burning wood, releasing a large amount of carbon stored in the soil. The soil on which energy crops are grown, can therefore not be used for growing food afterwards. On top of this, it takes years for new trees to grow back, raising the question of whether there is enough biomass available to meet the growing demand for bio-energy.
Biomass is more than wood from trees from the forest.
But: bio-energy is an umbrella term encompassing all kinds of energy products originating from trees, plants, algae and animals. Some types of bio-energy have a carbon circle which is very short. When burning agricultural by-products, for instance the stalks and stumps of tomato plants, the duration of the carbon cycle is less than a year. This means that the CO2 released during combustion will already have been captured from the air by new plants in a year's time.
And then there is the term 'residual wood'. When weak trees prevent the strong trees from growing well, the weaker trees are cut down. These trees are often not of sufficient quality to be useful for something, such as building homes or furniture. Branches are frequently broken off trees by strong storms and continuous supplies of wood become available during maintenance of gardens and estates which cannot be used for anything else. When you leave all of this wood and let nature takes its course, it will rot. And during the rotting of wood, the carbon connections stored in the wood will react with oxygen, which is then converted into CO2. Stated simply, the greenhouse gases are released one way or another. Whether you burn the wood or let it rot in nature. In that case, it would be better to use the (residual) wood as an energy source, so that you address that need and don't have to generate energy elsewhere which would release much more CO2.
Biomass can therefore definitely be sustainable. However, the discussion about biomass should not be debating whether, but how we can use biomass optimally in our fight against climate change. If you would like to know more about this, we recommend reading the article about biomass by Follow the money. Would you like to know more about the biomass system used at 't Lennepserf? If so, it goes without saying that you can contact us.