Turning Waste into Power: Celebrating Energy Efficiency Day with Agro-Waste Solutions

Energy Efficiency Day | 5 October 2025

The world will observe Energy Efficiency Day on October 5, 2025. A reminder of the critical role efficiency plays in tackling climate change, reducing energy costs, and safeguarding natural resources. Energy efficiency is not about giving up modern comforts; it involves doing more with less, reducing waste, and creating more innovative pathways to power our lives.

The African Paradox: Abundant Resources, Scarce Energy

Across Ghana and much of Africa, agricultural activities generate vast quantities of residues, including rice husks, corn stalks, cocoa pod husks, palm kernel shells, and many others. Most of these valuable resources are underutilised, burned in the open, left to rot, or dumped as waste that pollutes the environment and contributes to greenhouse gas emissions. Yet, at the same time, many rural communities face energy poverty. According to the International Energy Agency (IEA), more than 600 million Africans lack access to reliable electricity. The paradox is apparent: an abundance of resources on one side, scarcity of energy on the other.

At the heart of my research is the perspective that "waste is not waste until it is wasted", seeing agricultural residues not as a burden, but as an opportunity to generate clean energy for improved livelihoods.

In the Lab: Researchers developing and testing microwave catalytic pyrolysis systems tailored to African biomass resources.

Microwave Catalytic Pyrolysis: Innovating for Efficiency

Unlike traditional pyrolysis, which relies on external heating, microwave catalytic pyrolysis (MCP) utilises microwave energy to heat agro-waste internally. This makes the process:

• Faster: Microwaves ensure uniform heating, speeding up reactions.

• More efficient: Less energy is wasted compared to conventional heating methods.

• Cleaner: When paired with catalysts, MCP reduces emissions and improves product quality.

The process yields three valuable products:

1. Bio-oil – A potential alternative fuel for cooking, heating, or powering small agro-industries.

2. Biochar – A carbon-rich material that, when returned to farms, improves soil fertility, boosts crop yields, and sequesters carbon.

3. Syngas – A combustible gas used for electricity or thermal applications.

This closed-loop system exemplifies energy efficiency in action, i.e. turning what would have been wasted into high-value energy resources while reducing pollution.

Biochar produced from rice husks. Returning carbon to the soil while improving fertility and crop yields.

Powering Energy Efficiency Through Agro-Waste Innovation

The theme of World Energy Efficiency Day, using less, wasting less, achieving more, aligns directly with my research in MCP in the following ways:

• Efficient Resource Use: Instead of discarding agro-residues, we convert them into energy, maximising the value of existing resources.

• Reduced Energy Waste: MCP minimises energy losses during conversion compared to conventional pyrolysis.

• Climate Action: MCP lowers greenhouse gas emissions by displacing fossil fuels and reducing open burning.

• Affordable Energy Access: Decentralised production of bio-oil and syngas provides rural communities with local, renewable, and cost-effective energy solutions.

In other words, this work transforms waste-to-energy efficiency into a practical reality.

 A Community-Based Circular Economy

Our project will be piloted in Samanhu, near Tarkwa, Ghana, where farmers will actively participate in supplying feedstocks and testing the products. This model will ensure:

• Biochar returns to the soil, improving agricultural productivity.

• Bio-oil and syngas are tested in households and small-scale processors for cooking, heating, and power generation.

• Knowledge transfer occurs through workshops with students, technicians, and local entrepreneurs.

By embedding energy innovation within farming communities, the project aims to promote circular economy principles, where nothing goes to waste and every by-product finds a productive use.

Agricultural residue, such as maize stalks, holds untapped energy potential.

Broader Impact for Africa

By innovating with our resources, Africa can reduce dependency on imported fuels and take charge of its energy future, efficiently and sustainably. Africa's transition to clean and affordable energy requires more than large-scale solar farms and wind projects. It also requires localised, efficient technologies that communities can own, operate, and benefit from. Microwave catalytic pyrolysis offers precisely that. With Africa's vast biomass resources, the technology could reshape rural energy landscapes, improve food security through soil enhancement, and contribute to achieving SDGs 7 (Affordable and Clean Energy), 12 (Responsible Consumption and Production), and 13 (Climate Action).

Looking Ahead on Energy Efficiency Day

This World Energy Efficiency Day reminds us that efficiency is not just about better appliances or more intelligent buildings; it's also about rethinking waste. Technologies like MCP represent a powerful opportunity in Africa, where waste and energy challenges often coexist. Through continuous research, collaboration with local farmers, and support from policymakers, we can scale up this solution. The future lies in closing loops, reducing waste, and creating clean energy systems that empower communities. On this day, as we reflect on how to make our world more energy-efficient, I am convinced that the answer lies not only in consuming less but also in innovating more, especially with what we already have in abundance: agricultural residues.

Ato Fanyin-Martin, PhD