The creative endeavours to find innovative new ways to improve sustainability and reduce our dependence on fossil fuels can boggle the mind.
There have been some interesting headline seen across the spectrum. There have been studies for instance on how to exploit the gases from cow dung to turn it into cleaner energy. This would happen through use of an anaerobic digester, something used for a different but equally powerful purpose.
In Seville, 48,000 trees litter the streets in the winter months with 5.7m kilograms of bitter fruit. This creates hazards for pedestrians as well as a big clean up operation.
The municipal water company had a bright idea. They introduced a trial to produce electricity using methane from fermenting the wasted oranges.
Electricity through biogas
The excess oranges go through a process of juice extraction for the generation of electricity through biogas. The excess waste is then composted to become fertiliser which farms benefit from.
As part of the purification process, the organic matter in the wastewater is stabilised. This happens through an anaerobic digestion which helps generate methane-rich biogas. This gas is then used as fuel in co-generation engines to produce electricity.
“The project started as a result of EMASESA’s interest in achieving energy self-sufficiency in the urban wastewater treatment process,” according to the company’s CEO, Jaime Palop.
EMASESA aims to use this trial to achieve energy self-sufficiency for its Wastewater Treatment Plant in the city. The facility already generates electricity from organic matter.
The plant is expected to generate about 1,500 kWh, enough to power 150 homes. If all the city’s wasted oranges were recycled in this fashion, the energy put back into the grid would power 73,000 homes.
Surplus electricity generated
The plan is to put any surplus electricity generated into the grid by 2023.
Declared to be leading the way on energy efficiency, Juan Espadas Cejas (the mayor of Seville) said, “Emasesa is now a role model in Spain for sustainability and the fight against energy climate change”.
This is a great example of how industry leaders can show true innovation and transform a problem into a solution, and how one city’s problem of oranges littering the streets can be utilised to produce energy and power 73,000 homes.