The Future May be Orange: Seville is Turning Leftover Oranges into Renewable Energy

Seville, the Spanish city famed for its oranges, is now utilising the fruit to generate electricity. Native of Asia and introduced by the Arabs over 1,000 years ago, these bitter oranges have adapted well to the southern Spanish climate. A whopping 48,000 orange trees spread to all corners of Seville, bearing fruit known for its fresh, intense, and acidic flavour. In cooperation with the City of Seville’s Department for Parks and Gardens, the city’s municipal water company Emasesa is showcasing its commitment to a circular economy through a recent pilot scheme launched to test the viability of using unwanted oranges to produce renewable energy.

Emasesa aims to extract the juice from the fruit to create biogas, a renewable form of energy produced by the breakdown of organic matter, such as food waste and plant materials. Biogas can be used in various ways, including as vehicle fuel and for heating and electricity. Last year, scientists from Australia turned tequila into biofuel for cars. In this instance, the biogas is intended to power the EDAR Copero Wastewater Treatment Plant (WWTP) in Seville.

The city council employed 200 people to collect 35 tonnes of oranges on and around public roads. While the juice from the oranges served the purpose of this scheme, the peel has been composted and transformed into fertiliser for fields.

Throughout the winter months, the orange trees deposit on the streets, creating sticky pavements and attracting swarms of flies. These deposits are also hazardous for pedestrians and unfortunate for the city’s cleaning department. “It’s not just about saving money”, commented Benigno López, the head of Emasesa’s environmental department. He continues, “the oranges are a problem for the city, and we’re producing added value from waste”.

The project is expected to generate around 1,500 kWh, which is equivalent to the consumption of 150 homes. At the launch of the project, Juan Espadas Cejas, Mayor of Seville, stated that Emasesa is a role model in the sustainability world. This project is helping Spain work towards switching its electricity system to entirely renewable sources by the year 2050, an ambitious goal announced in 2018. To accomplish this, and continue to fight the effects of climate change, one-fifth of the state budget is to go towards sustainability efforts.

The team behind this project is enthusiastic about the potential of the city’s vast quantity of unwanted fruit and hopes that it will soon be possible to recycle it all. Although this goal would require an investment of €250,000 from the city, it is estimated that if all of the leftover oranges were recycled and the energy put back into the grid, 73,000 homes could be powered.