Utilizing the potential of wastewater heat as a renewable energy source

Reimagining waste by-products as viable energy sources 

The REFLOW pilot city Berlin is using data-driven marketable solutions towards climate-neutral heating. The vision is to extend usage and mainstream wastewater heat recovery, while reducing energy emissions. As a European pioneer, the Berlin pilot has a unique approach to match demand and supply with a ‘Waste Water Heat Radar’ that puts attention in data privacy and safety. 

Wastewater is currently being categorized as a by-product of water being used in households as well as industry. However, wastewater contains thermal energy which is lost when entering the sewage system. Utilizing the potential of wastewater heat, with the support of municipal procurement, has the capacity to generate a viable energy source.  

The Berlin pilot aims at raising awareness and supporting the development of conscious energy consumption, whilst simultaneously offering appropriate sustainable business models and marketable solutions. The solution is approached in a holistic way, whereby different actors from the energy supply chain are included, such as energy buyers and suppliers. The aim is that the successful implementation of this circular strategy in Berlin will inspire other municipalities to adapt and apply similar solutions.    

Wastewater heat for a transition towards climate neutrality

The world is currently facing the impacts of the unsustainable extraction and use of scarce resources. As a response, Germany has committed to climate neutrality from 2045 onwards. To this end, the municipality of Berlin is putting in place guidelines for a sustainable transition and climate protection. Part of the 2045 commitment is Berlin’s Energy and Climate Protection Programme 2030 (BEK 2030) and the digital monitoring and information system (diBEK), a framework to move away from continuously relying on conventional energy streams and appropriate backbone digital infrastructure.

Berlin pilot’s proposal is to focus on the intersection between society, economy, environment and data science, with a compelling opportunity: Wastewater heat. However there exists a gap between technological implementation and availability of quantitative and qualitative data. The proposed solution is bridging this gap by providing a data-driven web application that maps the potential of wastewater heat, therefore closing the loop between energy availability and energy need.

Since we are dealing here with a highly regulated market setting, a multi-stakeholder approach is needed that revolves around two main axes: (i) Enabling communication and dissemination for the wider citizen audience in order to raise awareness of the potential of the solution, and (ii) working together with industry, property owners, developers, architects, water utility companies and suppliers of equipment for a successful and holistic implementation.

Berlin’s pathway to change: a user-centred approach 

There are five main components comprising Berlin’s pathways to change: (1) technology development, (2) awareness raising, (3) generating interest, (4) implementation and (5) exploitation or replicability. All activities within Reflow have a strong user-centred approach and are supporting and reinforcing each other. The strategic outputs are digital-driven applications and explanatory videos.  

The data-driven application is a platform that maps demand and supply and generates matches between actors. It is transparently showcasing the potential of wastewater heat and is mainly targeting municipal decision makers. Furthermore, an illustrative video explains the solution for a diverse audience. 

Combined these two outputs are aimed at increasing awareness, while supporting the potential recovery of wastewater heat. This can significantly reduce energy costs, and can prove a major contribution to a sustainable energy transition on a municipal level

Data-driven futures for climate action 

The Berlin pilot is mainly targeting the United Nations’ Sustainable Development Goals: (6) Clean water and sanitation, (7) Affordable and clean energy, (11) Sustainable cities and communities and (13) Climate action. Beyond the Reflow project lifetime, the Berlin pilot is envisioning that through their efforts a wider audience of citizens will be acquainted with the potential of wastewater heat. Identified local opportunities during the project are laying the pathway across the interested public towards a solid implementation. For example, stepping stones of this pathway are influencing a sustainable legal structure, including media and collaborating with key decision-makers. The pilot aims to provide a successful and sustainable business model which can be applied in Berlin and beyond.  

During Reflow, the pilot has been approached by large energy companies which are interested in building upon the first iteration of the ‘Waste Water Heat Radar’. The international scope of such energy companies amplifies the impact on a larger region when combined with an impact-driven organisation. The collaboration with such a partner would roll out the radar across key geographic markets with a higher credibility and would provide a great opportunity for the future of energy markets.  Therefore, the Berlin pilot is not only aligning its actions with the national and global agenda, but also hopes to continuously aid the efforts on climate action.

Bridging the gap between technological implementation, transparent data-driven applications and citizen readiness is challenging. However, the general public’s demand for ever more sustainable cities is rising, and this puts additional motivation to come up with innovative and creative solutions. The intricate deployment of wastewater heat as a viable energy source needs a multi-stakeholder approach, systematic technological solutions, and concrete local communication and dissemination strategies. Despite the difficulties it is a process worth initiating, that can inspire other cities along the same energy transition path.