• Energy Research

The private motor vehicles are significantly important means of transportation in modern lifestyle, however, these also contribute to a large proportion of the total air pollution and primary energy consumption. In order to develop green transportation system, it becomes imperative to use integrated technologies to achieve reduced emissions and utilize renewable energy. Electric vehicles (EVs) have been considered as one of these technologies to transform the traditional vehicle mix. However, the uptake of EV has been debated on factors like cost, performance (autonomous mileage), charging point infrastructure construction, energy saving, policy and end users’ adaptation. Present study investigates the technology feasibility (which usually refer to EVs’ cost, EV charging, supplier’s customer services quality, EV travel performance) and users’ adaptation of EV in Beijing, which is a key driver for the EV uptake into the Beijing transportation system. The relevant data have been collected and analyzed in the form of questionnaire survey around all of these factors. While considering the user perception and satisfaction, safety of charging and energy bills have also been investigated. According to the data analysis, it has been found the policy of ‘No traffic restrictions for EVs’ (the traffic restrictions means for certain date, from Monday to Friday the motor vehicles with the last register number of 1 and 6, 2 and 7, 3 and 8, 4 and 9, 5 and 0, are restricted to travel, respectively), the availability of the charging infrastructure and technical support are the most significant factors affecting the users’ opinions on using EVs.

The current rollout of smart meters for gas and electricity, both in the UK and internationally, will help suppliers to better forecast demand and supply accurate bills to consumers. However, even with an in-home display (IHD), the benefits of a smart meter to a domestic customer are limited by the so-called ‘double invisibility’ of energy [1] and the standardisation of IHD design for an imagined home ‘micro-resource manager’ [2]. Furthermore, low-income households may be limited in the benefits they can reap from such systems; already living within a tight budget, suggestions for further energy-related cost savings may be detrimental to their health and wellbeing. This makes it important that the impact of actions taken to save energy is communicated. This can be done using indoor environmental measures, including carbon dioxide, relative humidity and temperature, as part of an integrated meter and sensor system (IMSS) and an associated IHD or digital application. Such a system gives users the ability to make informed decisions about their energy use and indoor environmental health. This paper explores the potential barriers to implementing an IMSS in practice. It explains how an IMSS was designed, based on a review of meter and sensor systems; details the process is taken to trial the IMSS in 19 social housing properties in the English Midlands; and makes recommendations for a larger scale rollout of IMSSs. The paper also reviews current progress in cloud storage and security as relevant to IMSSs and smart metering.

Abstract The transition of householders towards optimal energy use in the residential sector has proved to be challenging, with human energy-use behaviour been identified as one of the factors behind the setback. Social interventions geared towards engaging and making energy end users aware of their energy consumption and its footprint on the environment have been conducted in the past. Forty-six papers on the outcome of these social intervention were reviewed and categorized in this article based on the major strategies applied in anticipation of behaviour change. This paper shares information on the techniques used for the interventions, to what degree each intervention was successful or not and why it was adjudged successful or otherwise. It further explores some of the problems associated with the interventions and their reporting, followed by suggestions on how study practices can be improved. The techniques discussed include the use energy labels, energy performance certificates, energy auditing, prompts, norm appeals, commitments, economic incentives and disincentives, feedbacks, community-based initiatives, benchmarking, goal setting and gamification. Feedbacks, gamification, goal setting and community-based initiatives proved to be the most effective as they all recorded average energy savings of above 20%. Interventions practices can be performed individually, though a combination of complementary intervention tools have been observed to be effective.

Abstract The thermal behaviors of a solar chimney incorporating with organic phase change material (PCM) RT-42 unit under different heat fluxes are studied in this paper. For the numerical model, effective heat capacity method is employed to analyze the performance of RT-42, while the average thermo-physical property approach is used to describe the PCM/fins component. The PCM behaviors during its melting and solidification processes, absorber surface temperature, mass flow rate, and inlet and outlet air temperature difference have been investigated. The numerical results give good agreements with the experimental results. The comprehensive investigations under various heat fluxes from 100 to 800 W/m 2 are carried out by using the verified model. The numerical results show that the performance of the system deteriorates sharply once the heat flux is or lower than 500 W/m 2 , but not big improvement if the heat flux is higher than 700 W/m 2 . Therefore, the performance of the system is highly dependent on the solar radiation. The application of high effective thermal conductivity enhancers can further improve the performance of the chimney under lower solar radiation.

Biogas is one of the options to improve the current serious energy and environment situation in China. However, biogas application is limited in China due to instabilities in quantity and quality of biomass. These instabilities are largely influenced by the local environment and climate. Merging non-upgraded biogas into the natural gas (NG) distributing system can (i) increase utilisation, (ii) reduce carbon intensity of gas pipe network and (iii) promote renewable energy usages. However, merging biogas into the gas pipe network comes with lots of challenges. This paper investigates the approaches of merging biogas into the NG distributing system. The interchangeabilities between the mixed bionatural gas and the China's 12T standard gas are evaluated based on several indices. This study results indicate that the maximal mixing volume ratio of non-upgraded biogas to the typical piped natural gas is 14.7% when the Wobbe number and combustion potential are used as determining indices.

Abstract For some renewable energy such as solar energy, the mismatch between the side of generation and demand should be tackled by thermal energy storage techniques with high energy density and low thermal losses. Thermochemical energy storage is a promising technology to meet these requirements. Within a thermochemical energy storage system, reactor is one of the critical components to achieve the optimal performance. While few studies have investigated the three-phase reactor applied in open thermochemical system in building’s application. This study presents a numerical description of a three-phase thermochemical reactor with air, solid thermochemical material and water flow. Zeolite 13X has been selected as the working thermochemical material and experimental tests have been conducted to obtain the temperature profiles in both the charging and discharging processes. A two dimensional numerical model of the reactors has been developed, verified and validated. A good agreement has been obtained by comparing the numerical and experimental results with the root mean square percent error ranging from 6.02% to 12.29%. Additionally, parameters sensitivity analysis has been conducted for reference diffusivity, heterogeneity factor, and initial water uptake of the zeolite. The numerical model and the investigation provide the tool for reactor design optimisation, charging and discharging processes evaluation and reactor performance improvement.