• Energy Research
• 11. Sustainability close
• DE close
• KR close
• Fraunhofer Society close

With about 22%, the transport sector is one of the largest global emitters of the greenhouse gas CO₂. Long-distance road freight transport accounts for a large and rising share within this sector. For this reason, in February 2019, the European Union agreed to introduce CO₂ emission standards following Canada, China, Japan and the United States. One way to reduce CO₂ emissions from long-distance road freight transport is to use alternative powertrains in trucks — especially heavy-duty vehicles (HDV) because of their high mileage, weight and fuel consumption. Multiple alternative fuels and powertrains (AFPs) have been proposed as potential options to lower CO₂ emissions. However, the current research does not paint a clear picture of the path towards decarbonizing transport that uses AFPs in HDVs. The aim of this literature review is to understand the current state of research on the market diffusion of HDVs with alternative powertrains. We present a summary of market diffusion studies of AFPs in HDVs, including their methods, main findings and policy recommendations. We compare and synthesize the results of these studies to identify strengths and weaknesses in the field, and to propose further options to improve AFP HDV market diffusion modelling. All the studies expect AFPs on a small scale in their reference scenarios under current regulations. In climate protection scenarios, however, AFPs dominate the market, indicating their positive effect on CO₂ reduction. There is a high degree of uncertainty regarding the emergence of a superior AFP technology for HDVs. The authors of this review recommend more research into policy measures, and that infrastructure development and energy supply should be included in order to obtain a holistic understanding of modelling AFP market diffusion for HDVs.

AbstractIn 2008 the German Ministry of Economic Affairs and Energy launched an initiative for new or retrofitted energy-efficient school buildings as focus area within their research programme “EnOB” (Energy Optimised Buildings). The initiative (www.eneff-schule.de) comprises three different energy levels:•Best practice schools with energy-efficient renovations above the requirements in the energy-saving ordinance•Three-liter-house schools with energy needs for heating, hot water and auxiliary below 34 kWh/m2year•Plus energy schools that produce more energy than they use in the annual balanceCurrently three different plus energy school buildings have been planned, realized and monitored within the initiative, two of them being renovations (Stuttgart and Rostock), the last one being a new school building (Hohen Neuendorf). The three energy concepts include rather different technologies to generate heat and to reduce the energy consumption of ventilation and lighting systems. This is partly due to the research initiative approach of “EnEff:Schule” that asks for testing innovative technologies. There is however a general tendency to:•Low U-values of the building envelope with about 0.11–0.15W/m2K at the walls and roof, 0.10W/m2K for new base plates and 0.20–0.34W/m2K for renovated ground slabs and basement ceilings and 0.80W/m2K for windows•Large PV areas to compensate for the remaining energy use, sometimes in combination with other technologies or systems that generate electricity•Mechanical ventilation systems with high heat recovery rates but in combination with natural ventilation•User-dependent control strategies for ventilation and heating•Use of daylight at both the window/solar shading side and the electrical lighting controlThe paper compares the different technologies used at the building envelope, the heating, ventilation and lighting systems, the calculated and measured energy consumptions and the building costs.

In order to achieve long-term targets for energy savings and emission reductions, substantial savings will be needed from existing buildings. For example, a recent analysis for the USA examines aggressive strategies to cut carbon emissions in half by 2040 and finds that in order to achieve this emission reduction target, more than half of existing buildings will need comprehensive energy efficiency retrofits. Germany is targeting an overall primary energy consumption reduction of 50% in 2050 including increasing building renovation rate to 2% per year. In France, ambitious targets have also been set for existing buildings: 50% reduction of primary energy consumption in 2050 compared to the 2012 level. Multiple countries have realized the importance of comprehensive building retrofits and have begun to adopt policies to spur these improvements. For example, Germany is emphasizing grants and loans through the KfW Development Bank, complemented with building and heating system labels, a new “heating check” programme, and possible technical renovation requirements. France has established a goal of bringing all buildings up to “A” performance level (on their A–G scale) by 2050 in order for them to be sold or leased, with lower performance levels required as soon as 2020. In the USA, the focus has been on a combination of rating and disclosure of energy use, financing, and technical assistance. Focused community approaches show promise. This paper summarizes the efforts, successes and challenges, future directions, and savings of building retrofit policies in the three countries. We conclude by contrasting the three countries and discussing areas of opportunity for these and other countries.

Life Cycle Assessment (LCA) is increasingly being applied in corporate accounting. Recently, especially carbon footprinting (CF) has been adopted as ‘LCA light’ in accordance with the Greenhouse Gas Protocol. According to the strategy ‘balance, reduce, substitute, compensate’, the approach is intended to provide the basis for optimization towards climate neutrality. However, two major problems arise: (1) due to the predominant focus on climate neutrality, other decisive life-cycle impact categories are often ignored, resulting in a misrecognition of potential trade-offs, and (2) LCA is not perceived as an equal method alongside cost and value-added accounting in everyday business, as it relies on a fundamentally different system understanding. In this paper, we present basic considerations for merging the business and life-cycle perspectives and introduce a novel accounting system that combines elements of traditional operational value-added accounting, process and material flow analysis as well as LCA. The method is based on an extended system thinking, a set of principles, a calculation system, and external cost factors for the impact categories climate change, stratospheric ozone depletion, air pollution, eutrophication and acidification. As a scientifically robust assessment method, the presented approach is intended to be applied in everyday operations in manufacturing companies, providing a foundation for a fundamental change in industrial thought patterns on the way to the total avoidance of negative environmental impacts (i.e., environmental neutrality). Therefore, this is validated in two application examples in the German special tools industry, proving its practicability and reproducibility as well as the suitability of specifically derived indicators for the selective optimization of production systems.

Energy system models underpin decisions by energy system planners and operators. Energy system modelling faces a transformation: accounting for changing meteorological conditions imposed by climate change. To enable that transformation, a community of practice in energy-climate modelling has started to form that aims to better integrate energy system models with weather and climate models. Here, we evaluate the disconnects between the energy system and climate modelling communities, then lay out a research agenda to bridge those disconnects. In the near-term, we propose interdisciplinary activities for expediting uptake of future climate data in energy system modelling. In the long-term, we propose a transdisciplinary approach to enable development of (1) energy-system-tailored climate datasets for historical and future meteorological conditions and (2) energy system models that can effectively leverage those datasets. This agenda increases the odds of meeting ambitious climate mitigation goals by systematically capturing and mitigating climate risk in energy sector decision making. MTC, JW and LPS contributed equally to this manuscript. 25 pages, 2 figures. Fixed typos in manuscript title. This perspective is based on the discussion held at the 2021 Next Generations Challenges in Energy-Climate Modelling (NextGenEC'21) workshop

Abstract Indonesia is among the countries with the largest planned coal power capacity additions worldwide, thereby posing a substantial challenge for global climate change mitigation goals. To understand the underlying political drivers, we carry out expert interviews and examine how individual actors and their objectives, as well as the country context influence energy policy formulation. We find that under President Joko Widodo, energy policy formulation has been driven by the development of public infrastructure, while securing popularity for the presidential election in 2019. State-owned enterprises represent a source of political patronage and are employed to achieve those goals. Diminishing export markets have incentivized the politically well-connected and highly concentrated Indonesian coal industry to lobby for the construction of coal-fired power plants in order to raise domestic demand. There is also a strong incentive to sustain coal mining as a key economic activity, as associated royalties significantly contribute to local and national public budgets. Local pollution and climate change mitigation are of low priority. Despite the government’s documented awareness of the energy sector as the biggest contributor to future emissions, climate protection is narrowly framed as a forestry and land-use issue.

To reduce greenhouse gas emissions, nations have introduced energy efficiency regulations for new and existing buildings. This has been considered advantageous as more efficient building envelopes would reduce energy consumed to heat and cool home interiors to within accepted thermal comfort bandwidths. However, as these methods have been adopted, many nations have identified an unintended visible presence of surface and interstitial condensation and mould in new code-compliant buildings. In Australia, it has been estimated that up to 50% of Australian houses constructed in the last decade (2006–2016) have a presence of condensation and mould. Australia introduced its first condensation and mould-related building regulations for new homes in 2019. This paper reports on the hygrothermal and mould growth analysis of the most common low-rise residential external wall system, a timber-framed clay masonry veneer wall. A key component of this paper discusses the application of innovative methods in the Australian context. The external wall’s moisture accumulation and mould growth were simulated for a period of ten years using the transient hygrothermal simulation tool, WUFI® Pro, and the mould growth model, WUFI® VTT. This study identified significant risks for this typical external wall system when constructed in a temperate climate.