Building performance evaluation of domestic energy efficient retrofits in current and future climates

Approximately half of the houses in Northern Ireland were built before any form of minimum thermal specification or energy efficiency standard was enforced. Furthermore, 44% of households are categorised as being in fuel poverty; spending more than 10% of the household income to heat the house to bring it to an acceptable level of thermal comfort. To bring existing housing stock up to an acceptable standard, retrofitting for improving the energy efficiency is essential and it is also necessary to study the effectiveness of such improvements in future climate scenarios. This paper presents the results from a year-long performance monitoring of two houses that have undergone retrofits to improve energy efficiency. Using wireless sensor technology internal temperature, humidity, external weather, household gas and electricity usage were monitored for a year. Simulations using IES-VE dynamic building modelling software were calibrated using the monitoring data to ASHARE Guideline 14 standards. The energy performance and the internal environment of the houses were then assessed for current and future climate scenarios and the results show that there is a need for a holistic balanced strategy for retrofitting.

Circuit-aware design of energy-efficient massive MIMO systems

Densification is a key to greater throughput in cellular networks. The full potential of coordinated multipoint (CoMP) can be realized by massive multiple-input multiple-output (MIMO) systems, where each base station (BS) has very many antennas. However, the improved throughput comes at the price of more infrastructure; hardware cost and circuit power consumption scale linearly/affinely with the number of antennas. In this paper, we show that one can make the circuit power increase with only the square root of the number of antennas by circuit-aware system design. To this end, we derive achievable user rates for a system model with hardware imperfections and show how the level of imperfections can be gradually increased while maintaining high throughput. The connection between this scaling law and the circuit power consumption is established for different circuits at the BS.

An analysis of wind curtailment and constraint at a nodal level

Many countries have set challenging wind power targets to achieve by 2020. This paper implements a realistic analysis of curtailment and constraint of wind energy at a nodal level using a unit commitment and economic dispatch model of the Irish Single Electricity Market in 2020. The key findings show that significant reduction in curtailment can be achieved when the system non-synchronous penetration limit increases from 65% to 75%. For the period analyzed, this results in a decreased total generation cost and a reduction in the dispatch-down of wind. However, some nodes experience significant dispatch-down of wind, which can be in the order of 40%. This work illustrates the importance of implementing analysis at a nodal level for the purpose of power system planning.

Mapping Ireland’s Energy Pathways: Characterizing and Catalyzing Transition

In 2015 Ireland has arguably begun to make its first bold steps in confronting the challenges of energy transition, with the objective of a “low carbon, climate resilient and environmentally sustainable economy by the end of the
year 2050” expressed in the 2015 Climate Action and Low Carbon Development Bill and the 2015 Energy Bill acknowledging that energy transformation relied on a new breed of ‘energy citizens’. These represent the first formal articulation of Ireland’s ambition to engage in a radical, long-term and far-reaching transition process, and raises a myriad of questions over how this can be operationalised, resourced and whether it can maintain political momentum. A range of perspectives on these issues is provided in the growing body of literature on transition theories (Rotmans et al 2001, Markard et al 2012) and the inter-disciplinary EPA-funded CC Transitions project, based at Queen’s University Belfast, represents an attempt to translate this into the context of Ireland’s institutions and technological profile. By relating this to international research on sustainability transitions, which conceptualises transitions as multi-level, multi-phase and multi-actor processes, this paper will explore the opportunities of alternative pathways that could take Ireland towards a more progressing, inclusive and effective low carbon future. Drawing on a number of case studies it will highlight some of the capacities for transition required in Irish society: where these exist, how they are being built or enabled, and the barriers to wider social change.