M. Newborough

Energy consumption in UK households: Impact of domestic electrical appliances

The social-psychological aspects of energy use in UK households have been reviewed. A major survey, which focused on identifying environmental attitudes and beliefs, energy-use behaviour, ownership levels for certain appliances and their utilisation patterns, was undertaken among householders resident in the south-east of England. The results indicate that members of the general public are (i) interested in receiving information concerning household energy use and the associated environmental impact, and (ii) willing to modify their behaviour in order to reduce household energy consumption and environmental damage. Therefore, there is an urgent need to provide end-users with accurate energy-consumption and environmental-impact information, persuasively presented, to stimulate energy-rational and environmentally sustainable behaviour. For each major domestic electrical appliance, the survey data permit estimates of the variations in energy consumption per household and of the aggregate annual consumption nationally.

Auditing energy use in cities

`Energy auditing’ as a technique for obtaining a ‘snapshot’ of the energy flows in a city or urban conurbation is discussed in the context of meeting national and international targets for CO2 emissions abatement. An audit methodology is presented which addresses the key questions: Who needs to be involved in the audit? How should the city or conurbation be divided? What data are required? How might these data be obtained and then analysed? Which are the areas of significant consumption? A basis for setting local targets for reducing future energy consumption and CO2 emissions is presented. The scope for auditing major cities and conurbations in the United Kingdom is identified with reference to implementing Local Agenda 21 and satisfying CO2 emissions reduction targets.

Designs, thermal performances and other factors concerning cooking equipment and associated facilities

Cooking appliances are notoriously wasteful of energy. The present survey and investigations outline the history and behaviours of the main forms of cooking equipment available and indicate the energy efficiencies of the various designs. Improvements regarding equipment design, cooking techiques and consumer education are suggested from an energy-thrift perspective.

Intelligent automatic electrical-load management for networks of major domestic appliances

The utilisation of household equipment (i.e. for space-heating, water-heating, cooking, washing, cleaning, drying, food-preservation, entertainment, and personal care) influences significantly the UKs peak electrical demand. By developing intelligent load-management facilities for domestic dwellings, which do not infringe adversely on personal lifestyles, peak demands may be reduced. A significant saving in the predicted national requirement for reserve power-generating plant should thereby the achieved. Such home-automation systems would also help facilitate the introduction of a responsive time-of-use electricity-pricing system, which passes on the real-time cost of power generation to the end user. Once realised, this would encourage consumers to be more energy-conscious when purchasing and using electrical equipment.

Electrolyser-based energy management : A means for optimising the exploitation of variable renewable-energy resources in stand-alone applications

Abstract Electrolyser-based energy management (EBM) offers a versatile means for optimising the process of harnessing energy supplies derived from variable and/or intermittent renewable resources, e.g. solar (photo-voltaic), wind, wave and tidal. In general, EBM systems consist of an electrolyser, water and gas (hydrogen and, optimally, oxygen) storage and management systems and a means of (re-) generating electricity, e.g. a fuel cell. Such systems achieve their management via energy conversion and storage, this operational principle being referred to as electricity supply-and-demand management (ESDM). Implementation of this principle offers significant advantages in the utilisation of variable and/or intermittent renewable resources, as it permits electricity generated during periods of high-availability/low-demand to be “time-shifted” for subsequent re-supply during periods of low-availability/high-demand. Furthermore, EBM systems have the important advantage over other ESDM systems that the stored form of energy is readily utilisable as a pollution-free gas supply for thermal end-uses. This reconversion route significantly enhances the overall energy-conversion efficiency. Electrolyser and fuel cells based upon proton-exchange membrane technologies are preferred because these afford considerable operational advantages over any alternatives. In this paper these advantages are expanded upon and preliminary data based on these ideas are presented.

Effects of operative behaviours and management planning on energy consumptions in kitchens

The ways in which individual catering appliances were used, as well as the planning of meal production, have been studied for five catering facilities (namely for 3 canteens, an hotel and a psychiatric hospital). For each kitchen, activity charts were deduced from the observed patterns of use of each appliance. Several of the identified practices, such as switching-on appliances well before necessary, incurred excessive energy consumptions. Other established habits, such as permitting inordinately-long cooking or holding periods for the food at elevated temperatures, increased energy consumptions and adversely affected the quality of the food produced. The undertaken surveys provided evidence for: 1. (i) the need to review existing practices within kitchens, in order to promote the adoption of more efficient operational procedures and equipment use; 2. (ii) the need, as a systematic requirement, to train staff in the effective uses of new appliances; 3. (iii) the incorporation of programmed timers to switch-on, as well as switch-off, equipment and so relieve staff of the worry that these items will not be at the desired temperatures (and so not be available for immediate use) when required; and 4. (iv) the removal from the kitchen of equipment which is no longer needed or is of low efficiency.

Heat transfers from a horizontal cylinder in a rectangular enclosure

A 9.5Â mm-diameter, horizontal, cylindrical heater was traversed horizontally and vertically within a 750Â mm long, 350Â mmx350Â mm square-sectioned relatively-cold enclosure for two values of the Rayleigh number, namely 7.0x104 and 1.0x105. The maximum steady-state rate of natural convection occurred when the heater was located parallel to and near a vertical wall (i.e. with 0.25

Multi-purpose mathematical model for electromagnetic-heating processes

Electromagnetic-heating processes are reviewed. Theoretical analyses of electromagnetic-heating processes in isotropic materials of various regular geometries and with ranges of physical properties have been undertaken. The mathematical model so devised may be employed as a design tool in the development of a product/process and may thereby serve as a means for reducing the necessity for experimentation, which is usually expensive. In particular, the educational benefits of employing such a multi-purpose mathematical model, to improve the understanding of the thermal effects of electromagnetic-heating techniques, are emphasised.

Improving the thermal performances of domestic electric ovens

Experimental analyses of the thermal performances of (i) various heating-element configurations, (ii) a low-emissivity internal oven-lining, (iii) control systems for regulating internal air temperatures, and (iv) various thermal-insulation systems for an oven have been undertaken. Overall, a substantial increase in the thermal efficiency was achieved, i.e. from 17 to 26%. This compares favourably with the value of 13%, as measured for a typical commercially available domestic oven.

Evolution of energy-efficient food-preparation facilities

The catering industry is one of the more energy-profligate sectors of British society, if assessed according to the ratio of the amount of energy used divided by that needed if efficient systems and practices were employed to achieve the same quality of end-product. Consequently, worthwhile energy-thrift opportunities exist for reducing energy consumption in British kitchens, whether associated with canteens, cafes, restaurants or hotels. To facilitate encouraging the implementation of these improvements, detailed energy-conscious recommendations are proffered in this survey with respect to the structural and argonomic designs of food-preparation facilities. Also, advice which should enable caterers to select (and demand from appliance manufactures) more energy-efficient equipment for initial installation in, or when refurbishing, their kitchens is presented. By the economically justifiable introduction of these proposals, it is predicted that a reduction in overall energy usage in the catering industry of at least 25% (i.e. about £1·25 x 108 p.a. in the UK at 1987 prices) may then be achieved.