• Energy Research
• other engineering and technologies close
• 13. Climate action close
• 11. Sustainability close
• 15. Life on land close
• DE close
• CA close

Given the global energy and environmental situation, the European Union has been issuing directives with increasingly demanding requirements in term of the energy efficiency in buildings. The international competition of sustainable houses, Solar Decathlon Europe (SDE), is aligned with these European objectives. SDE houses are low energy solar buildings that must reach the near to zero energy houses’ goal. In the 2012 edition, in order to emphasize its significance, the Energy Efficiency Contest was added. SDE houses’ interior comfort, functioning and energy performance is monitored. The monitoring data can give an idea about the efficiency of the houses. However, a jury comprised by international experts is responsible for carrying out the houses energy efficiency evaluation. Passive strategies and houses services are analyzed. Additionally, the jury's assessment has been compared with the behavior of the houses during the monitoring period. Comparative studies make emphasis on the energy aspects, houses functioning and their interior comfort. Conclusions include thoughts related with the evaluation process, the results of the comparative studies and suggestions for the next competitions.

The successful electricity grid integration of solar energy into day-ahead markets requires at least hourly resolved 48 h forecasts. Technologies as photovoltaics and non-concentrating solar thermal technologies make use of global horizontal irradiance (GHI) forecasts, while all concentrating technologies both from the photovoltaic and the thermal sector require direct normal irradiances (DNI). The European Centre for Medium-Range Weather Forecasts (ECMWF) has recently changed towards providing direct as well as global irradiances. Additionally, the MACC (Monitoring Atmospheric Composition & Climate) near-real time services provide daily analysis and forecasts of aerosol properties in preparation of the upcoming European Copernicus programme. The operational ECMWF/IFS (Integrated Forecast System) forecast system will in the medium term profit from the Copernicus service aerosol forecasts. Therefore, within the MACC‑II project specific experiment runs were performed allowing for the assessment of the performance gain of these potential future capabilities. Also the potential impact of providing forecasts with hourly output resolution compared to three-hourly resolved forecasts is investigated. The inclusion of the new aerosol climatology in October 2003 improved both the GHI and DNI forecasts remarkably, while the change towards a new radiation scheme in 2007 only had minor and partly even unfavourable impacts on the performance indicators. For GHI, larger RMSE (root mean square error) values are found for broken/overcast conditions than for scattered cloud fields. For DNI, the findings are opposite with larger RMSE values for scattered clouds compared to overcast/broken cloud situations. The introduction of direct irradiances as an output parameter in the operational IFS version has not resulted in a general performance improvement with respect to biases and RMSE compared to the widely used Skartveit et al. (1998) global to direct irradiance conversion scheme. Cloudy situations and especially thin ice cloud cases are forecasted much better with respect to biases and RMSE, but large biases are introduced in clear sky cases. When applying the MACC aerosol scheme to include aerosol direct effects, an improvement especially in DNI biases is found for cloud free cases as expected. However, a performance decrease is found for water cloud cases. It is assumed that this is caused by the lack of an explicit modelling of cloud-aerosol interactions, while other meteorological forcings for cloud processes like the temperature field are modified by the aerosols.

AbstractThe presented synthesis of the title compounds (II), (IV), (VI) and (VIII) is extremely simple and highly efficient without the use of any chromatographic purification.

Abstract Hybrid energy storage is a multi-modal approach to store and supply different forms of energy (electricity, heat, cold) simultaneously. This is an important sector coupling approach and enables large scale flexibility for a deep decarbonization of energy systems. Two different proposed energy storages – power-to-heat-to-X energy storage (PHXES) and pumped thermal energy storage (PTES) – are investigated in detail in this work towards their potential towards a hybrid deployment. The techno-economic analysis includes thermodynamic flowsheet simulations and unified cost estimations based on the used equipment. It is shown that the main input data set (e.g. working fluid selection, turbomachinery efficiency, pinch temperatures) has a strong influence on storage roundtrip efficiency in the thermodynamic simulations, but also on storage costs. Cost decrease and performance increase can be conflicting development targets, and it is not clear if future energy systems rather require technologies with the highest storage efficiencies or if low cost is an important prerequisite. PHXES and three variants of PTES are implemented into a simplified energy system model of the city of Hamburg that comprises the electric load and heat demand of the district heating system. Two scenarios (fossil benchmark and 80% decarbonization) are used to select the technologies and their capacities that allow the most cost-effective energy supply solution by a linear-programming optimization procedure. Large scale renewable power generation and hybrid energy storage play the major roles in the decarbonization scenario. PHXES with a storage capacity of 69 GWh, hot water storage (3.6 GWh) and a battery system (430 MWh) are part of the cost-optimal solution. A cost sensitivity analysis shows that a total cost reduction of 60–80% is required for PTES to become competitive in this model scenario.

This paper presents an experimental study of indoor thermal environment near a full-scale glass facade with different types of shading devices under varying climatic conditions in winter. Interior glazing and shading temperature, operative temperature and radiant temperature asymmetry were measured for facade sections with roller shades and venetian blinds at different positions. Interior glass surface temperatures can be high during sunny days with low outdoor temperature. Shading systems significantly improved operative temperature and radiant temperature asymmetry during cold sunny days, depending on their properties and tilt angle. During cloudy days the impact was smaller, however the shading layers could still decrease the amount of heat loss through the facade. A transient building thermal model, which also calculates indoor environmental indices under the presence of solar radiation, was developed and compared with the experimental measurements. Part II of this paper uses this validated model with a transient, two-node thermal comfort model (including transmitted solar radiation) for assessment of indoor environmental conditions with different building envelope and shading properties, facade location and orientation.

Abstract Recharging infrastructure (RI) deployment plays a vital role in improving the public recharging availability for transport electrification. Decarbonizing transportation using low-emission electricity requires massive RI network. Even though the consumers are reluctant to purchase electric vehicles (EVs) until RIs are sufficiently placed, the investors are not willing to invest in RIs due to recharging demand uncertainties. Therefore, a scientific planning framework is needed to ensure the sustainable deployment of EV-RIs in complex networks. In this study, a lifecycle thinking-based multi-period infrastructure-planning framework is proposed to develop sustainable public EV-RIs in an urban context. This framework consists of a temporal model to find the dynamic EV-RI demands, a stochastic model to obtain travel distances, and a multi-objective optimization model to select the best desirable capacities and locations for potential EV-RIs. A case study of a typical medium-scale municipality in Canada was assessed using the proposed framework and validated using conventional infrastructure planning scenarios. The geo-processing data, regional travel behaviors, and recharging characteristics were used as model inputs. The results of the case study showed that the proposed framework can be used to estimate multi-period public recharging demands, minimize lifecycle costs, maximize service coverage and infrastructure utilization, and ensure reasonable paybacks compared to conventional planning approaches. Moreover, this framework can be used to compare different investment assistances, which are required in the early stages of the RI deployment process to encourage investors. Furthermore, government and private institutions can use this framework to identify recharging demands, permitting, and developing RIs in the long-run.

Abstract The residential sector accounts for most of energy-consumption in developing countries in the form of traditional energy. The use of commercial energy is nominal and confined mostly to urban areas where fuelwood is already monetized. A model, based on an end-use/process analysis approach, is developed on a spreadsheet, which is capable of simulating scenarios to address issues of increasing traditional energy-demand caused by population growth, sustainable supply capacity of the existing energy resources, potential for development of new and renewable energy resources, technology. This paper is divided into two parts: general energy issues and the modelling approach, and the application of this approach to Nepal in the context of fuelwood-supply sustainability.

Abstract Alternative fuel vehicles (AFV) may help to reduce global CO2 emissions from the transport sector. One obstacle for AFV market diffusion is the lack of refueling infrastructure which prevents potential users from buying AFVs. Meanwhile infrastructure suppliers await market developments before investing in an extensive infrastructure roll-out. This mutual interaction has been a field of research for several years and a variety of modeling approaches have been applied. This paper aims at reviewing models of combined AFV and refueling infrastructure market diffusion and pointing out research gaps. We retrieve stylized facts which models should account for from empirical studies on natural gas vehicles, user acceptance analyses on AFVs and technical restraints of plug-in electric vehicles (PEVs) and fuel cell electric vehicles (FCEVs). Ten interaction models are evaluated with respect to the identified aspects. We find that simulation is the most common approach for an interaction model. Besides, the majority of the examined stylized facts is covered by the models. However, models for FCEVs could be improved by reflecting the transport of fuel to refueling infrastructure while new models on PEVs should include charging duration, frequency and charging station ownership.