Showing papers by "Conny Bakker published in 2012"

Insights into the design, use and implementation of home energy management systems

Abstract: Between 2008 and 2011, three different home energy management systems (HEMS)that give feedback on energy consumption were implemented in households in the Netherlands. Home energy management systems are defined as intermediary devices that can visualise, monitor and/or manage domestic gas and/or electricity consumption. Through a series of questionnaires, interviews, focus groups and usability tests, a wide range of knowledge was gathered on factors influencing the effectiveness of the three systems. The resulting insights were structured with the help of a conceptual model, which outlines the various interactions between users, energy monitors, and their social and physical environments. The insights provide a broad spectrum of factors to be considered for the successful design and implementation of home energy management systems. This paper aims to provoke an open discussion to ascertain the value of the different factors and further the development of effective and useful HEMS.

Environmental sizing of smartphone batteries

Abstract: Smartphone use has increased at a phenomenal pace worldwide. In 2011 more smartphones have been sold than desktop pc's, notebooks, netbooks and tablets together. The total worldwide smartphone sales reached 472 million units in 2011, and 149 million of them were sold in the fourth quarter of 2011. The smartphone is, like almost every other mobile device, powered by batteries, limited in size and therefore capacity, which makes energy management paramount. While global demand and use of mobile devices continuously expands, the energy density of smartphone batteries has grown at an insignificant rate, but the use period still decreases because of high loads and big screens. In this paper we have studied the power breakdown of five smartphones on sale in 2011. We have defined three different user profiles for “heavy”, “moderate” and “light” users and we can state that theoretically it is sensible to re-size the battery based on the user profile. While keeping the user period acceptable we can decrease the battery capacity for moderate and light users with 25%, reducing the worldwide energy needed to product smartphone batteries with 2.1 to 3.4PJ per year. In practice the aging of the battery will result in a decreasing battery capacity over its life. When taking this into account most batteries comply with the moderate users and only a resizing strategy for the light users is sensible. This will account for only 20% of all users and can result in a worldwide decrease of energy needed for producing the smartphone batteries with 0.5 to 0.9PJ.

Rethinking eco-design priorities; the case of the Econova television

Abstract: Eco-design heuristics (defined as experience-based techniques for problem solving) can play a useful role in helping designers prioritize eco-design strategies. One of these eco-design heuristics (the ‘use phase’ heuristic) is: Frequently used electric and electronic products usually have, over their life span, a dominant impact in the use phase. Modern mobile devices like smart phones however have their dominant impact in the production phase and therefore challenge this heuristic. The paper asked whether this could be a trend and whether we might find more electric and electronic products that challenge the ‘use phase’ heuristic. We found that in general, the development of highly energy-efficient consumer electronics and the widespread shortening of product lifespans have indeed started to shift the focus to the materials and production phase of the life cycle. The case study of the Econova television showed that with a ‘best in class’ product like this TV, it is not possible to establish which life cycle phase is dominant. These findings led to several additions to the ‘use phase’ heuristic.

A business model framework for product life extension

Abstract: Product life extension is an increase in the utilization period of products. Design research on product life extension strategies has so far mainly focused on technical aspects of products, like ‘prevention engineering’ or ‘design for repair, maintenance and upgradability’, and on individual consumer-product relationships, like ‘design for emotional durability’. The viability of product life extension in a business context and the associated consequences for product design, have however remained largely unexplored. In this paper a starting point is provided for this exploration, by outlining the development of a business model framework for product life extension, using strategies for product life extension and mapping these against common elements of contemporary business model theory. Drawing on case studies, examples are used to show how the framework can be used in practice by designers and business developers.

Eco-design opportunities for critical material supply risks

Abstract: A number of recent publications point to the important role of eco-design approaches in risk mitigation for critical materials supply The core of eco-design is life cycle thinking - usually as some form of Life Cycle Assessment (LCA) approach together with a set of generic guidelines such as checklists, etc There has however been little appraisal of the extent to which eco-design offers opportunities in the context of critical material supply risks It is this gap that this paper will tackle Through research with 30 companies in The Netherlands, a small number see the phenomena of critical materials as an opportunity to seek competitive advantage via new product designs There is also evidence that those companies see opportunities via an eco-design based approach but there are some issues that need to be addressed before such eco-design approaches could be more successful and used widely

Assessing the overall life cycle impact of home energy management systems

Abstract: An ever-increasing body of research explores the effectiveness of Home Energy Management systems (HEMS) in achieving energy savings. To date, however, the overall life cycle impact of the HEMS itself has not been taken into account. Thus, no assessment has been made whether the amount of energy saved (esaved) outweighs the energy needed for production, use and disposal (einvested). To determine whether esaved>einvested, a lifecycle assessment was conducted comparing three HEMS in six usage scenarios. The results show that the impact is dependent on the type of HEMS, and that the benefits do not always outweigh the (environmental) costs.