Power-to-Gas (PtG) is an innovative energy concept which will help to incorporate flexibility into future energy systems, increasingly characterised by the use of fluctuating renewable electricity. One PtG option, dubbed Power-to Hydrogen (PtH2) is to produce hydrogen from water electrolysis applying cheap renewable electricity in times of surplus and providing it for re-electrification in times of electricity shortages or to other hydrogen end-users, whatever promises the best business opportunities. It has been shown by recent studies that these can be best exploited, if PtH2 simultaneously supplies hydrogen to more than one end-use sector. The combination of electricity and mobility sectors has been earmarked as being specifically relevant, promising high utilization of the electrolysers and hence possible revenues. It is the purpose of the HyBalance project to demonstrate the concept of multi-sectoral hydrogen end-use in the renewable energy friendly environment of wind-rich Denmark at Megawatt scale with a PtH2 plant. A group of partners representing all steps along the renewable electricity to hydrogen to end-use value chain have convened to develop a PtH2 demonstration plant. This plant will be designed for combined operation providing both grid balancing services and hydrogen for industry and as a fuel for transport in the community of Hobro in the Danish province of Nordjylland. The plant will be used to demonstrate its feasibility to identifying potential revenue streams from PtH2 under today’s and future constraints (regulatory environment, state-of-art of key technologies), simultaneously applying most recent developments for hydrogen distribution and storage. Relevant applications in the hydrogen production site’s proximity are: hydrogen refuelling stations for fuel cell cars and buses in Hobro, local industry and, as perspective, hydrogen storage in salt caverns located in Hvornum and Lille Torup.

The municipal wastewater in Europe contains a potential chemical energy of 87,500 GWh per year in its organic fraction, which is equivalent to the output of 12 large power stations. Due to the currently applied technologies and related energy loss at each process step, wastewater treatment in Europe today consumes instead the equivalent of more than 2 power stations. Many operators are thus targeting incremental energy efficiency towards energy neutrality, but recent studies have shown that with novel process schemes using existing technologies, sewage treatment plants could actually become a new source of renewable energy, without compromising the treatment performance. The project POWERSTEP aims at demonstrating such innovative concepts in first full scale references for each essential process step in order to design energy positive wastewater treatment plants with currently available technologies. The following processes will be demonstrated in 6 full-scale case studies located in 4 European countries: enhanced carbon extraction (pre-filtration), innovative nitrogen removal processes (advanced control, main-stream deammonification, duckweed reactor), power-to-gas (biogas upgrade) with smart grid approach, heat-to-power concepts (thermoelectric recovery in CHP unit, steam rankine cycle, heat storage concepts), and innovative process water treatment (nitritation, membrane ammonia stripping). These individual technology assessments will merge into integrative activities such as treatment scheme modelling and design, global energy and heat management, carbon footprinting, integrated design options, as well as extensive dissemination activities. POWERSTEP will demonstrate the novel concepts and design treatment schemes of wastewater treatment plants that will be net energy producers, paving the way towards large implementation of such approaches and quick market penetration and supporting the business plans of participating technology providers.