Sustainable

Sustainability is one of the fundamental pillars of Mostra's work. We are a small-scale festival, aware of both our limitations and our potential contribution, but also driven by a strong commitment to creating positive change within the electronic music scene across multiple areas. Over the years, we have implemented concrete actions that reinforce our commitment to becoming a festival that is more respectful of its environment, embraces a social perspective, and reflects critically on the realities that surround us.

The starting point, with ReRoot

During the first edition of our Mostra'm programme in 2022, we organised a workshop together with ReRoot, a London-based non-profit organisation that firmly believes in the power of electronic music as a force for positive change. ReRoot develops goals and promotes collaborative actions to address systemic environmental and social challenges.

The participatory workshop "Envisioning a Sustainable Mostra Festival" marked the starting point for developing our sustainability roadmap. Inspired by the Vision 2030 for a sustainable electronic music industry created by ReRoot and DJs For Climate Action, ReRoot partnered with Mostra to take on the role of Green Ambassador within the project and has accompanied us in developing this roadmap ever since.

With the support of our strategic partner ReRoot, we developed a three-year roadmap  based on three key areas of work: 1) How we show up; 2) Locations and operations; 3) Travel and hospitality. After every edition, we publish an annual update  detailing our progress and achievements while outlining our priorities for the future.

Travel and accommodation

At Mostra, we recognise that one of the largest contributors to any festival's environmental footprint comes from artist and guest travel, particularly international flights. One of the actions we have developed over the years focuses on visitors travelling to Mostra from outside Barcelona. In this regard, we have partnered with accommodation providers across the city that implement environmentally responsible practices and maintain a strong social commitment, including Hostal Grau Barcelona, Andante Hotel, Casa Jam Barcelona and Twentytú Hostel Barcelona.

Festival pass holders can benefit from discounted accommodation at these venues, allowing them to support one of the festival's core pillars—sustainability—throughout their stay in Barcelona during Mostra.

Along the same lines, we reduce the number of flights taken by international artists by programming fewer overseas acts, helping to lower the festival's carbon footprint and reduce the environmental impact of mobility. For artists travelling from outside Barcelona, we prioritise train travel over flights by including an additional complimentary night's accommodation in their contracts for journeys exceeding 600 kilometres, encouraging the use of rail transport whenever possible. At the same time, around one fifth of the artists on our line-up are Barcelona-based, reinforcing our commitment to supporting the local scene while also reducing travel-related emissions.

We actively promote public transport through awareness campaigns encouraging audiences to travel to the festival using more sustainable means of transport. During the 2024 edition, for example, we operated up to three collective shuttle buses from Castell de Montjuïc back to the city centre to facilitate the audience's return journey after the festival.

Energy, catering and materials

Also in 2024, we decided to power one of the festival's stages using batteries supplied by 100% renewable energy, avoiding the use of fossil fuels. This conscious decision enabled much cleaner energy consumption to power both the sound system and the bar area at the Foso stage.

When it comes to food and beverage services, we prioritise working with social integration organisations and entities from Barcelona's social and solidarity economy, including the cooperatives Abarka (2022, 2023, 2024) and La Raíz (2024), formed by African and Latin American migrant collectives respectively, as well as Menjador Ca la Rosa (2023) and La Deskomunal (2026).

We also use reusable cups and disposable cardboard tableware across bars and catering services to minimise the use of single-use plastics. During the 2024 edition, we donated part of the revenue generated through cup returns to Kantina Migrante, a collective of migrant women based in Barcelona.

Regarding the production of festival spaces and materials, we prioritise receiving donated carpets, fabrics and pillow fillings in order to give them a second life. Using these materials, we created mattresses from the street banners that promoted the 2024 edition of the festival across Barcelona. Since then, they have served as resting areas during subsequent editions, allowing audiences to relax between performances or enjoy the music in a horizontal listening position.

In this way, we have repurposed nearly 300 street banners installed throughout the city with municipal support, transforming them into oversized cushion covers. At the same time, we found a new use for the filling material itself: surplus foam from another Barcelona-based project that would otherwise have been extremely difficult to recycle, giving it a second life as a durable, functional and sustainable object.

Other measures we have implemented include renting or prioritising the shared use of materials instead of purchasing new ones through organisations such as Barcelona's Banc de Recursos Mancomunats; focusing our communication and marketing campaigns primarily on digital channels while using recycled and certified paper whenever printed materials are necessary; and ensuring that surplus food and other reusable materials are donated to organisations with a social purpose.

A socially engaged festival

Mostra is also a socially engaged festival that addresses contemporary issues with a clear social perspective. In December 2023, during our first intercontinental ExtraMostra event in Colombia, we organised a fundraising campaign for children from local communities in Pereira together with the collectives Natural and Communion. One year later, in December 2024, we concluded another fundraising campaign supporting people affected by the devastating floods caused by the DANA storm in Valencia, following our first ExtraMostra event of the season in the city.

As part of the Mostra'm programme, we have also promoted spaces for critical reflection, such as Charlie C. Thomas's performative lecture, which explored the evolution of the heart symbol—from its association with love to its role within digital culture and capitalism—in order to examine how far-right movements across Europe and the United States have appropriated this emotional imagery to legitimise exclusionary narratives under the appearance of care and belonging.

The carbon footprint

In 2024, we produced our first carbon footprint assessment to establish medium-term mitigation measures. This report served as a preliminary assessment that would enable us to calculate the carbon footprint of the 2025 edition with greater accuracy and establish it as our baseline year. Conducting a preliminary assessment was particularly necessary because air travel represented such a significant proportion of our estimated emissions and because more accurate data was needed to verify those calculations.

To better understand our environmental impact and identify opportunities to reduce it, we carried out our first comprehensive carbon footprint assessment in 2025  in collaboration with ReRoot and Zero Consulting, a Barcelona-based environmental auditing consultancy. The project received funding from the Catalan Institute for Cultural Companies (ICEC) through the programme Grants for actions that reduce environmental impact and promote or improve accessibility for companies or organisations in the cultural sector.