Open Access

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.

On 26 January 2019, the Commission on Growth, Structural Change and Employment recommended that no more coal-fired power plants would be operated in Germany by 2038 at the latest. In this paper the Wuppertal Institute comments on the results of the Commission and makes recommendations for the current necessary steps for the climate and innovation policy in Europe, Germany and North Rhine-Westphalia.

Motivated by, inter alia, the increasing energy prices, the security of energy supply and climate change, the new EU "Action Plan for Energy Efficiency: Realising the Potential" (EEAP), sets out the policies and measures required to be implemented over the next six years to achieve the EU's goal of reducing annual primary energy consumption by about 20 % by 2020. By increasing energy efficiency, the security of energy supply and the reduction of carbon emissions are also improved. The paper will analyse the 20 % target of the new EEAP for the energy demand side by comparison with different recent energy scenarios for the EU. It will therefore review the recommended policies and measures and examine, in which energy demand sectors energy efficiency may be increased and to which extend. The main focus is whether the recommended policies and actions will be sufficient and which additional measures may be useful, if additional measures are needed.