Open Access

The EU Horizon 2020 project HiEff-BioPower (grant agreement No 727330, duration: 10/2016 - 09/2021) aimed at the development of a new, innovative, fuel flexible and highly efficient biomass CHP technology for a capacity range of 1 to 10 MW total energy output, suitable e.g. for on-site generation at larger residential apartment buildings or local heat grids. The new technology shall define a new milestone in terms of CHP efficiency and contribute to a sustainable energy supply based on renewable energies using otherwise unused residual biomass. It consists of a fuel-flexible updraft gasification technology with ultra-low particulate matter emissions, an integrated gas cleaning system and a solid oxide fuel cell (SOFC). The technology shall be applicable for a wide fuel spectrum for residual biomass (wood pellets, wood chips or selected agricultural fuels like agro-pellets) and achieve high gross electric (40%) and overall (90%) efficiencies as well as almost zero gaseous and particulate matter (PM) emissions (close or below the level of detection) as non-energy benefits. At the end of the project, final technology data has become available, as well as techno-economic analyses and market studies. Based on this data, this paper presents final results from the environmental impact assessment of the new HiEff-BioPower technology.

Agriculture is a major sector responsible for greenhouse gas emissions. Local food production can contribute to reducing transport-related emissions. Since most of the worldwide population lives in cities, locally producing food implies practicing agriculture in urban and peri-urban areas. Exemplary, we analyze the potential to produce fresh vegetables within Berlin, Germany. We investigate the spatial extent of five different urban spaces for soil-based agriculture or gardening, i.e., non-built residential areas, allotment gardens, rooftops, supermarket parking lots, and cemeteries. We also quantify inputs required for such food production in terms of water, human resources, and investment. Our findings highlight that up to 82% of Berlin’s vegetable demand could be produced within the city, based on a reasonable validation of existing areas. Meeting this potential requires 42 km2 of urban spaces for cultivation, a considerable amount of irrigation water, around 17 thousand gardeners, and over 750 million EUR of initial investments. The final vegetable cost would be around 2 EUR to 10 EUR per kg without any profit margin. We conclude that it is realistic to produce a significant amount of Berlin's vegetable demand within the city, even if it comes with great challenges.