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.

The South African government started the development of a basic energy efficiency policy framework in 2005, including a voluntary label for refrigerators. This initial label was the intended precursor to a mandatory standards and labelling (S&L) programme, but the impacts achieved were only very limited. Based on this first experience, the South African Bureau of Standards (SABS) formed in 2008 a working group for the development of the new and more specific South African National Standard SANS 941. This standard identifies energy efficiency requirements, labelling and measurement methods as well as the maximum allowable standby power for a set of appliances as reliable basis for introducing a mandatory regulation. Nevertheless, due to many existing barriers, such as lack of funding and low priority assigned to the initiative, a very long period passed by between the S&L planning and final policy implementation. Finally, in November 2014, the South African government published mandatory performance standards coming into force in 2015/2016 for a first set of appliances consisting of refrigerators, washing machines, dryers, dishwashers, electric water heaters, ovens, A/C and heat pumps. To analyse the effectiveness of the new S&L programme and the potential influence of delays in the implementing process, the authors performed an immediate first-hand evaluation of the new policy. As analytical reference base for available energy efficiency potentials, results from bottom-up scenario calculations will be presented exemplarily as case study for cold appliances covered by the S&L programme. A retrospective market study will show market trends before policy implementation and compare results with the new mandatory requirements. For the further policy analysis, a programme theory approach will be applied, in order to better understand why, how and under what conditions the policy works. Relationships with other energy efficiency policies and measures as well as positive or negative effects will be described. Furthermore, cause-impact relationships will be analysed to explain the functioning of the policy. Finally, success and failure factors will illustrate what needs to be done to achieve the desired energy efficiency targets. Henceforth, even though this study does not assess the direct transferability of the South African S&L programme to other regions, its findings could be relevant and useful for countries planning the implementation of similar policies.