Moreover, the biomass obtained shows a particularly high energy potential relative to its digestibility level, with a methane production capacity of around 200-300 litres of gas per kilogram of biomass processed by anaerobic digestion. The microalgae also allow the purification of wastewater to a high standard.

Launched in May 2011, the €12 million five-year project has already completed its pilot phase (the first two years) in a 200 m² facility. The plans for the construction of the biomass plant are on schedule, and a one-hectare prototype is under construction. The project’s final phase will span 10 hectares.

In terms of surface area, this will be the first time a project of this scale (10 hectares of cultivation) will be implemented in the world for the cultivation of algae into bioenergy using wastewater treatment. In New Mexico, there is a 6-hectare biofuel production site – but this uses artificial fertilizer rather than waste nutrients. Various other installations around 10 hectares do exist but use food-based crops.

It is expected that by 2016, the biofuel produced by the All-gas project will be enough to power 200 vehicles. When the project reaches its demonstration phase, the biogas produced will be used to power public buses and garbage trucks in the region of Cadiz.

“This original new approach to bioenergy means that Spain’s 40 million population could power 200,000 vehicles every year with a single toilet flush,” said Frank Rogalla, project coordinator and FCC Aqualia’s director of innovation and technology. “The All-gas project is going to change the face of wastewater treatment by generating a valuable energy resource from what was previously considered undesirable waste.”

In recent years, the European Union has made a commitment to find new sources of clean energy. The current aim is that 20 per cent of the energy produced in Europe will come from renewable sources by 2020. The All-gas project has EU funding of €7.1 million.

Wastewater treatment actively consumes energy and resources. The All-gas project proposes using it, as well as CO₂, generated in biomass boilers from residuals such as garden waste or olive pits to feed the algae, which in turn are converted into biogas. A part of the biogas is CO₂, which gets separated from the biomethane and recycled.

"This is not only an R&D project, but also a way of reducing costs and investing in the protection of our natural environment,” said Nicolas Aragon, Chiclana’s environmental councillor. “Chiclana is a worldwide tourist destination and from now on, we will show that along with attracting visitors with our sunshine and beaches, we can also grow sustainable biofuel with our natural resources.”

The technology is said to avoid the controversy that surrounds other biofuel projects, which are based on large-scale food crops. Food-based biofuels have been criticized for raising food prices as well as having an adverse environmental effect. The All-gas system is also self-sufficient as it runs on the energy it produces and it is part of an integral water management system.

The All-Gas consortium is led by FCC Aqualia, and comprises five other organisations, from Germany (Fraunhofer-Gesellschaft), Austria (BDI), the Netherlands (Feyecon y Hygear) and the UK (University of Southampton).