Taofeeq Ibn-Mohammed

Environmental life cycle assessment and techno-economic analysis of triboelectric nanogenerators

As the world economy grows and industrialization of the developing countries increases, the demand for energy continues to rise. Triboelectric nanogenerators (TENGs) have been touted as having great potential for low-carbon, non-fossil fuel energy generation. Mechanical energies from, amongst others, body motion, vibration, wind and waves are captured and converted by TENGs to harvest electricity, thereby minimizing global fossil fuel consumption. However, only by ascertaining performance efficiency along with low material and manufacturing costs as well as a favorable environmental profile in comparison with other energy harvesting technologies, can the true potential of TENGs be established. This paper presents a detailed techno-economic lifecycle assessment of two representative examples of TENG modules, one with a high performance efficiency (Module A) and the other with a lower efficiency (Module B) both fabricated using low-cost materials. The results are discussed across a number of sustainability metrics in the context of other energy harvesting technologies, notably photovoltaics. Module A possesses a better environmental profile, lower cost of production, lower CO2 emissions and shorter energy payback period (EPBP) compared to Module B. However, the environmental profile of Module B is slightly degraded due to the higher content of acrylic in its architecture and higher electrical energy consumption during fabrication. The end of life scenario of acrylic is environmentally viable given its recyclability and reuse potential and it does not generate toxic gases that are harmful to humans and the environment during combustion processes due to its stability during exposure to ultraviolet radiation. Despite the adoption of a less optimum laboratory manufacturing route, TENG modules generally have a better environmental profile than commercialized Si based and organic solar cells, but Module B has a slightly higher energy payback period than PV technology based on perovskite-structured methyl ammonium lead iodide. Overall, we recommend that future research into TENGs should focus on improving system performance, material optimization and more importantly improving their lifespan to realize their full potential.

Drivers of U.S. toxicological footprints trajectory 1998–2013

By exploiting data from the Toxic Release Inventory of the United States, we have established that the toxicological footprint (TF) increased by 3.3% (88.4 Mt) between 1998 and 1999 and decreased by 39% (1088.5 Mt) between 1999 and 2013. From 1999 to 2006, the decreasing TF was driven by improvements in emissions intensity (i.e. gains in production efficiency) through toxic chemical management options: cleaner production; end of pipe treatment; transfer for further waste management; and production scale. In particular, the mining sector reduced its TF through outsourcing processes. Between 2006 and 2009, decreasing TF was due to decrease in consumption volume triggered by economic recession. Since 2009, the economic recovery increased TF, overwhelming the influence of improved emissions intensity through population growth, consumption and production structures. Accordingly, attaining a less-toxic economy and environment will be influenced by a combination of gains in production efficiency through improvement in emissions mitigation technologies and changes in consumption patterns. Overall, the current analysis highlights the structural dynamics of toxic chemical release and would inform future formulation of effective mitigation standards and management protocols towards the detoxification of the environment.

A quantitative model for environmentally sustainable supply chain performance measurement

Abstract The development of robust mechanisms for supply chain performance measurement have been identified as an integral step needed for the transition towards sustainable supply chain systems and a greener global economy. However, measuring the environmental performance of supply chains is a challenging task, due to several factors, such as the lack of standardised methodologies and the inherent multi-criteria nature of the problem. By leveraging the capability of a Multi-Regional Input–Output framework to handle the complex and global nature of supply chains, the current work presents a robust environmental sustainable performance measurement model underpinned by industrial lifecycle thinking. As a result, some theoretical insights are provided and an empirical application of the model to the Metal Products industry of the BRICS (Brazil, Russia, India, China, and South Africa) nations undertaken in an attempt to address some of the methodological and applied measurement challenges. In particular, this allowed the modelling of carbon emissions trends within, and between the BRICS nations and with the Rest-of-the-World over a 20-year period (1992–2011) as well as providing an opportunity to hypothesis on their future carbon emissions performances. Specific analyses of the Metal Product industry showed that demand represents the main driver for the increasing carbon footprint. However, the overall decline in reported carbon footprint was due to improvements in emissions intensity and efficiency gains induced by technology. The study further assesses the effects of imports and economic growth on carbon footprint and discusses the implications of the study to sustainability transition processes in the BRICS nations.

A Decision Support Framework for Evaluation of Environmentally and Economically Optimal Retrofit of Non-domestic Buildings

Currently, the building sector has an oversized carbon footprint as it represent the single largest contributor to global greenhouse gas emissions (GHG), with approximately one third of global energy end use taking place within buildings. The challenge to successfully reduce the energy consumption in the building sector is to find effective strategies for retrofitting existing buildings. Significant emissions reductions are possible from applying low carbon retrofit intervention options to existing buildings. The choice of low carbon retrofit intervention options involves evaluation of applicability, energy end uses, environmental impact and cost of application versus energy savings. To develop energy efficiency strategies for building stock, there is the need for optimised methodologies and decision aid tools to evaluate whole-life economic and net environmental gain of the options. This paper describes the development of an integrated framework for a Decision Support System (DSS) based on the optimal ranking and sequencing of retrofit options for emissions reduction in non-domestic buildings. The DSS framework integrates economic (cost) and net environmental (embodied and operational emissions) cost or benefit parameters and an optimization scheme to produce an output based on ranking principles such as marginal abatement cost curve (MACC). The methodology developed can be used to identify and communicate trade-offs between various refurbishment options to aid decisions that are informed both by environmental and financial considerations.

A Robust Model to Enhance Organisation Boardrooms’ Decision-Making Process Towards a Low Carbon Economy

The role of organisations in efforts to address negative externalities on the natural environment has become urgent. As such, an organisation-focused perspective would be a limited view point of addressing global environmental impacts on the natural environment. We argue that by drawing on resource-based view theory, development of decision support systems (DSS) is an example of how organisational competences which are rooted in technology can be directed and used to not just create value but also enhance environmental sustainability. To this end, we present a decision support model which seeks to provide stakeholders with a better understanding of how to effectively conduct energy savings investment to promote energy conservation and sustainability within organisation. Bridging knowledge domains, the model presented integrates the key variables of economic and net environmental benefits to produce optimal decisions. These variables are used within an optimisation scheme that consists of integrated modules for data input, sensitivity analysis and takes into account the use of a set of energy saving options that satisfies a range of criteria (environmental, demand, cost and resource constraints); hierarchical course of action; and the evaluations of ‘best’ case scenario based on marginal abatement cost methods and Pareto optimisation. The steps involved in the system development are presented and its usefulness is evaluated using a case study application. The results of the application are analysed and presented, verifying the feasibility of the model whilst encouraging further improvements and extensions. The methodology developed provides stakeholders with an efficient and reliable decision process that is informed by both environmental and financial considerations.

Using Policy Instruments to Drive Optimal Living and Sustainable Consumption in the Built and Natural Environment

In order to drive optimal living and sustainable consumption in the built and natural environment, there is the need to develop more sustainable, less energy-intensive systems and approaches that offer economic advantages, better operational performance, environmental merits and social acceptability. Measures to achieve these objectives including low-carbon technologies such as renewable energy generation technologies and energy efficiency measures are widely available today. Current focus on these technologies to reduce operational energy requirements has led to the neglect of embodied energy. This may result in obscuring the actual or net environmental gain for a given technology. Understanding the actual life cycle environmental gains is therefore necessary if a holistic effort in achieving sustainable built environment is to be attained. Furthermore, these environmental measures (operational and embodied) must be considered within an economic context. Against this backdrop, this chapter illustrates how policy instrument such as Marginal Abatement Cost Curve (MACC) can be used as a mechanism for evaluating low-carbon technologies taking into account both operational and embodied emissions and financial cost. The implication of emissions embodied in international trade flows within a MACC framework is also discussed.