Increasing urbanisation and climate change belong to the greatest challenges of the 21st century. A high share of global greenhouse gas emissions are estimated to originate in urban areas (40 % to 78 % according to UN Habitat 2010). Therefore, low carbon city strategies and concepts implicate large greenhouse gas (GHG) mitigation potentials. At the same time, with high population and infrastructure densities as well as concentrated economic activities, cities are particularly vulnerable to the impacts of climate change and need to adapt. Scarce natural resources further constrain the leeway for long-term, sustainable urban development. The Low Carbon Future Cities (LCFC) project aims at tapping this three-dimensional challenge and will develop an integrated strategy / roadmap, balancing low carbon development, gains in resource efficiency and adaptation to climate change. The study focuses on two pilot regions - one in China (Wuxi) and one in Germany (Düsseldorf+) - and is conducted by a German-Chinese research team supported by the German Stiftung Mercator. The paper gives an overview of first outcomes of the analysis of the status quo and assessment of the most likely developments regarding GHG emissions, climate impacts and resource use in Wuxi. The project developed an emission inventory for Wuxi to identify key sectors for further analysis and low carbon scenarios. The future development of energy demand and related CO2 emissions in 2030 were simulated in the current policy scenario (CPS), using five different sub-models. Selected aspects of Wuxi's current material and water flows were analysed and modelled for energy transformation and the building sector. Current and future climate impacts and vulnerability were investigated. Recent climatic changes and resulting damages were analysed, expected changes in temperature and precipitation in the coming four decades were projected using ensembles of three General Circulation Models. Although Wuxi's government started a path to implement a low carbon plan, the first results show that more ambitious efforts are needed to overcome the challenges faced.
Contemporary combined heat and power (CHP) systems are often based on fossil fuels, such as natural gas or heating oil. Thereby, small-scale cogeneration systems are intended to replace or complement traditional heating equipment in residential buildings. In addition to space heating or domestic hot water supply, electricity is generated for the own consumption of the building or to be sold to the electric power grid.
The adaptation of CHP-systems to renewable energy sources, such as solid biomass applications is challenging, because of feedstock composition and heat integration. Nevertheless, in particular smallscale CHP technologies based on biomass gasification and solid oxide fuel cells (SOFCs) offer significant potentials, also regarding important co-benefits, such as security of energy supply as well as emission reductions in terms of greenhouse gases or air pollutants. Besides emission or air quality regulations, the development of CHP technologies for clean on-site small-scale power generation is also strongly incentivised by energy efficiency policies for residential appliances, such as e.g. Ecodesign and Energy Labelling in the European Union (EU). Furthermore, solid residual biomass as renewable local energy source is best suited for decentralised operations such as micro-grids, also to reduce long-haul fuel transports. By this means such distributed energy resource technology can become an essential part of a forward-looking strategy for net zero energy or even smart plus energy buildings.
In this context, this paper presents preliminary impact assessment results and most recent environmental considerations from the EU Horizon 2020 project "FlexiFuel-SOFC" (Grant Agreement no. 641229), which aims at the development of a novel CHP system, consisting of a fuel flexible smallscale fixed-bed updraft gasifier technology, a compact gas cleaning concept and an SOFC for electricity generation. Besides sole system efficiencies, in particular resource and emission aspects of solid fuel combustion and net electricity effects need to be considered. The latter means that vastly less emission intensive gasifier-fuel cell CHP technologies cause significant less fuel related emissions than traditional heating systems, an effect which is further strengthened by avoided emissions from more emission intensive traditional grid electricity generation. As promising result, operation "net" emissions of such on-site generation installations may be virtually zero or even negative. Additionally, this paper scopes central regulatory instruments for small-scale CHP systems in the EU to discuss ways to improve the framework for system deployment.
The paper describes quantitative scenarios on a possible evolution of the EU petrochemical industry towards climate neutrality. This industry will be one of the remaining sectors in a climate neutral economy still handling hydrocarbon material to manufacture polymers. Concepts of a climate neutral chemical industry stress the need to consider the potential end-of-life emissions of polymers produced from fossil feedstock and draft the vision of using renewable electricity to produce hydrogen and to use renewable (hydro)carbon feedstock. The latter could be biomass, CO2 from the air or recycled feedstock from plastic waste streams.
The cost-optimization model used to develop the scenarios describes at which sites investments of industry in the production stock could take place in the future. Around 50 types of products, the related production processes and the respective sites have been collected in a database. The processes included cover the production chain from platform chemicals via intermediates to polymers. Pipelines allowing for efficient exchange of feedstock and platform chemicals between sites are taken into account as well. The model draws on this data to simulate capacity change at individual plants as well as plant utilization. Thus, a future European production network for petrochemicals with flows between the different sites and steps of the value chain can be sketched.
The scenarios described in this paper reveal how an electrification strategy could be implemented by European industry over time with minimized societal costs. Today's existing assets as well as geographical variance of energy supply and the development of demand for different plastic sorts are the major model drivers.
Finally, implications for the chemical industry, the energy system and national or regional governments are discussed.