Integrated Optimal Power Flow for Distribution Networks in Local and Urban Scales

This paper develops an integrated optimal power flow (OPF) tool for distribution networks in two spatial scales. In the local scale, the distribution network, the natural gas network, and the heat system are coordinated as a microgrid. In the urban scale, the impact of natural gas network is considered as constraints for the distribution network operation. The proposed approach incorporates unbalance three-phase electrical systems, natural gas systems, and combined cooling, heating, and power systems. The interactions among the above three energy systems are described by energy hub model combined with components capacity constraints. In order to efficiently accommodate the nonlinear constraint optimization problem, particle swarm optimization algorithm is employed to set the control variables in the OPF problem. Numerical studies indicate that by using the OPF method, the distribution network can be economically operated. Also, the tie-line power can be effectively managed.

Stable oxygen isotopes in irish oaks: potential for reconstructing local and regional climate

The long Irish oak tree-ring chronology, developed for archaeological dating and radiocarbon calibration, is the longest of any in northwest maritime Europe, spanning most of the Holocene (7,272 years). Unfortunately, the rings widths do not carry a strong climate signal and the record hasnever been satisfactorily applied for dendroclimatic reconstruction. This pilot study explores the potential for extracting a climate signal from Irish oaks by comparing the stable oxygen isotopes ratios from 10 oak tree cores (Quercus robur and Quercus petraea L.) collected across the Armagh region of NE Ireland with local and regional climatic and stable isotopic data. Statistically significant correlations between isotope ratios and the amount of summer precipitation (r = -0.44) point to the isotopic composition of summer rainfall as the dominant signal. Including the Armagh data into an extended regional oxygen isotope series did not reduce the correlation coefficient with regional precipitation (r = -0.68, p < 0.01). Correlations of this magnitude in dendro-hydroclimatology are typically restricted to trees growing at their ecological limits. This research suggests that there is considerable potential for including living trees and ancient timbers from Ireland into a regional composite to reconstruct the summer hydroclimate of Britain and Ireland.

Local Storage Meets Local Demand: A Technical Solution to Future Power Distribution System

Future power systems are expected to integrate large-scale stochastic and intermittent generation and load due to reduced use of fossil fuel resources, including renewable energy sources (RES) and electric vehicles (EV). Inclusion of such resources poses challenges for the dynamic stability of synchronous transmission and distribution networks, not least in terms of generation where system inertia may not be wholly governed by large-scale generation but displaced by small-scale and localised generation. Energy storage systems (ESS) can limit the impact of dispersed and distributed generation by offering supporting reserve while accommodating large-scale EV connection; the latter (load) also participating in storage provision. In this paper, a local energy storage system (LESS) is proposed. The structure, requirement and optimal sizing of the LESS are discussed. Three operating modes are detailed, including: 1) storage pack management; 2) normal operation; and 3) contingency operation. The proposed LESS scheme is evaluated using simulation studies based on data obtained from the Northern Ireland regional and residential network.

Archives and Copyright: Risk and Reform

This paper considers the place of the archive sector within the copyright regime, and how copyright impacts upon the preservation, access to, and use of archival holdings. It begins with a critical assessment of the current parameters of the UK copyright regime as it applies to the work of archivists, including recommendations for reform that have followed in the wake of the Gowers Review of Intellectual Property (2006-2010), the Hargreaves Review of Intellectual Property and Growth (2010-2011), the Consultation on Copyright (2011-12), as well as the government’s response thereto: Modernising Copyright (2012). It considers the various problems the copyright regime presents for archives undertaking mass digitisation projects as well as recent European and UK initiatives in this domain. It argues that the UK copyright regime, even when read in conjunction with current national and regional recommendations for reform, falls short of delivering a legal framework that would enable archivists to realise the full potential that comprehensive, universal online access to the country’s archival holdings would contribute to local and national democracy and accountability, to education, learning, and culture, and to the sense of identity and place for local people, communities and organisations. Ultimately, a case is made for the differential treatment of archives within the copyright regime – different, that is, from libraries and other related institutions operating within the cultural sector. The paper concludes with a policy recommendation that would greatly enhance the ability of archives to provide online access to their holdings, while at the same time safeguarding the economic interests of the authors and owners of copyright-protected work.