Blog Post

Transition to renewable energy: the need to produce clean energy.

Fueling the Future One Onion at a Time

On a vibrant Tuesday morning in 2050, you prepare to embark on your daily commute. You approach the morning shuttle, a marvel of futuristic engineering that hovers silently above the ground. Its sleek form captures the early light, casting a radiant silhouette against the cityscape. As you step up to the shuttle door, there’s no need for a ticket or a pass. Instead, a small receptacle by the door invites a different kind of fare. You drop in a handful of last night’s onion peels. The shuttle hums to life, powered by your culinary leftovers. This is no longer the realm of science fiction but the everyday reality of biomass conversion technology. In this new era, energy is not just harvested, it’s given back by each of us.

As we consider this future, let us explore the here and now: the transition to renewable energy sources, an essential shift to address and mitigate the consequences of climate change. Europe, like many other parts of the world, relies heavily on fossil fuels to meet its energy needs (Eurostat, 2024), but this dependence comes at a significant environmental cost. To move away from this damaging path, we must come together and adopt clean energy alternatives. Fortunately, the green energy options currently developed are very diverse, ranging from solar, wind, hydraulic, biomass, to geothermal energy. Each presents unique advantages and challenges, but collectively they offer a pathway to a sustainable and resilient energy future.

In this blog post, we will focus on renewable energy based on biomass conversion, aligning with the objectives of the FENIX project. Energy based on biomass conversion involves harnessing organic matter, much like the onion peel that might one day be your ticket to ride, to generate biogas, biomethane, and biofuels during decomposition.

Cooking up Energy

Currently, biogas production mainly uses agricultural biomass as feedstock, the so-called energy crops, such as rapeseed, sunflower, corn, and sugar cane. However, using agricultural land for energy instead of food cultivation stirs debate, especially with the looming need to nourish an estimated 9.8 billion people by 2050 (United Nations, 2017). Fortunately, biogas production is not limited to specific feedstocks and there is still huge untapped potential in the use of bio-waste (don’t have read it yet? link to previous blog)Bio-waste, representing 34% of municipal waste which is generated by human food consumption, is a significant source of economically valuable materials and essential nutrients that were once part of the soil. Unfortunately, since it is currently incinerated, landfilled or turned into compost, it results in the loss of large amount of these valuable nutrients.

On the other hand, recent years have seen a surge in technologies like anaerobic digestion (AD) and pyrolysis, which transform biomass into renewable energy in the form of biogas, electricity, or heat. However, these technologies often face economic viability challenges as they struggle to fully utilize all by-products, which are often seen as mere residual streams. Navigating these issues has proven to be a long and winding road; the high costs associated with waste management often diminish the potential profits from these by-products, limiting the overall economic efficiency and leaving much of their potential for sustainable development and circular economy unexplored.

Within the realm of bio-waste lies a wealth of untapped resources. These are not only capable of generating clean energy solutions but also valuable by-products such as biochar and digestate. These by-products are rich in nutrients that can serve as potential agricultural products, enhancing fertility, soil health and promoting a shift out of the fossil-based chemical fertilizers most widely used. By tapping into the potential of bio-waste for producing agronomic products such as fertilizers or soil amendments, we can cultivate more sustainable farming practices, thereby enhancing resilience and productivity in the face of environmental challenges. This creates a powerful synergy between renewable energywaste management, and sustainable agricultural practices, all while protecting soil health. By leveraging renewable energy sources like biomass or waste-to-energy technologies, we cut down on greenhouse gas emissions and reduce dependence on fossil fuels. At the same time, implementing effective waste management strategies, including valorisation, plays a crucial role in reducing pollution and conserving valuable resources.

Synergizing Energy, Waste, and Agriculture

In line with these principles, the FENIX project adopts innovative methods to produce soil amendments containing a blend of biochar and digestates out of bio-waste based renewable energy technologies. This involves employing a pyrolysis process to convert green waste from cities pruning into biochar and biogas. Additionally, we harness digestates as by-products from anaerobic digesters that use bio-waste from supermarkets to generate biogas. Subsequently, the biogas generated by these two technologies undergoes an upgrading process to produce biomethane, which is seamlessly integrated into the natural gas grid decreasing the dependency on the one from fossil origin. Through these multifaceted approaches, FENIX strives to advance sustainability and address pressing environmental challenges caused by the increasing energy requirements.

As we envision stepping into that 2050 commuter shuttle powered by last night’s dinner, we see not just a futuristic dream but a tangible future, one that projects like FENIX are actively building. By transforming everyday waste into powerful solutions, we can actively create this sustainable future.


Eurostat. (2024, May). Eurostat Stadistics Explained. Retrieved from Energy statistics - an overview:

United Nations. (2017). Department of Economic and Social Affairs. Obtenido de World population projected to reach 9.8 billion in 2050, and 11.2 billion in 2100:

By: J. Gómez, M. Romero
Editorial: L. Salinas
May 2024