una planta y una bombilla simbolizan la bioenergía

Reading time: 6 min

When we think of renewable energy, solar energy and wind energy are usually the first ones that come to mind. However, there’s a type of energy that’s generated from different kinds of biomass that is also the fastest growing renewable energy in recent years (up by 30% since 2018). It’s called bioenergy, and it’s one of the most promising options to replace fossil fuels.

What is bioenergy and how is it produced?

When we talk about "bioenergy," we are referring to energy derived from the conversion of biomass, also known as organic material, that can be used to generate heat, electricity, and fuel.

It has enormous potential as various types of organic waste can be converted into energy in a profitable and sustainable way. It's also fundamentally important in the energy transition given that it's a virtually carbon-neutral energy and promotes the circular economy by reusing resources.

Although it may seem like a novel concept, biomass was the first energy source to be used by humans (specifically, wood burning). Today, we use different methods to convert biomass into energy:

  • Thermochemical methods: By applying heat, biomass is converted into energy. These methods are suitable for raw materials with a lower degree of humidity. Pyrolysis, gasification, and combustion stand out as common examples.
  • Biochemical methods: The energy comes from the action of microorganisms that break down the molecules of biological waste. They are applied to materials with a higher moisture content. Some examples are fermentation and anaerobic digestion.

Types of bioenergy and applications

Hands holding pellets

Bioenergy from solid raw materials

The combustion of solid biomass is one of the most consolidated applications. Bioenergy can be produced from forestry and agricultural waste, such as firewood or straw, in both domestic and industrial applications. As of today, there’s a growing trend in the use of wood pellets, which are small cylinders made from forestry and wood industry waste. Their cleanliness, easy handling, cost-effectiveness, and high efficiency make them a reliable alternative to firewood for stoves and boilers.

A Repsol biofuel drum

Liquid biofuels

The transportation sector also benefits from bioenergy, in this case in the form of biofuels, which represent a commitment to sustainability in a sector that is particularly difficult to decarbonize. Advanced or second-generation biofuels are produced using agriculture or forestry waste, the organic part of municipal solid waste, and used vegetable oils. Additionally, some liquid renewable fuels, such as bioethanol, are also used for transportation or heating.


planta de biogás


Biogas, which is composed mainly of methane, is produced from the decomposition of waste such as manure, slurry, or organic municipal solid waste. It's mainly used to generate electrical and thermal energy.

Bioenergy with carbon capture and storage (BECCS)

Bioenergy with carbon capture and storage, or BECCS, is a solution aimed at removing CO2 emissions by using nature-based and technology-based processes.

  • In the first case, it consists of capturing CO2 through reforestation projects – trees that absorb CO2 from the atmosphere throughout their entire growth.
  • In the second case, CO2 emissions from industrial processes or directly from the air can be removed by capture systems and stored, for example, in rock formations (a process known as "geological sequestration"), or used as a raw material to manufacture other carbon-based products. By doing so, much of the emissions are prevented from reaching the atmosphere.

This technology has enormous potential, as the Fifth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC) shows that the range of negative emissions that this technology could achieve amounts to 22 gigatonnes per year

A hand adding fertilizers to a plant

Importance of bioenergy in the rural world

Without a doubt, farming is a strategic sector in the bioenergy field given that agricultural activity generates 17 million tonnes of dry waste from herbaceous and woody waste every year in Spain alone, which could replace 7 million tonnes of oil.

  • On the one hand, renewable gases produced by treating other waste from these sectors will make it possible to replace a total of 1.5 million tonnes of this fuel. Therefore, what was traditionally considered highly polluting waste is now being focused on to generate renewable energies.
  • Another one of its key points is its potential for creating jobs in rural areas, either in the management of forestry and agricultural waste or for energy crop cultivation. This would lead to an improvement in the quality of life of the rural population, as people would be able to access quality jobs without having to leave their towns and promote greater cohesion and stability.
  • On the other hand, there are pioneering projects aimed at boosting the value of the rural world and promoting greater energy independence while protecting the environment: bioenergy villages.

In these villages, biomass is used as renewable energy and is produced in the same place where it's consumed. In order to be considered a bioenergy village, at least 50% of the electrical and thermal energy consumption must correspond to the amount of bioenergy generated in the area. However, it's not only a matter of generating energy sustainably. It's also about using it efficiently. In Germany alone, there are 170 locations that are considered energy villages, but they can also be found in other countries like Austria and Romania.