http://hdl.handle.net/10468/708 Sat, 18 May 2013 22:35:30 GMT 2013-05-18T22:35:30Z http://hdl.handle.net/10468/1010 How much wind energy will be curtailed on the 2020 Irish power system? McGarrigle, E. V.; Deane, J. P.; Leahy, Paul G. This paper describes a model of the 2020 Irish electricity system which was developed and solved in a mixed integer programming, unit commitment and economic dispatch tool called PLEXOS. The model includes all generators on the island of Ireland, a simplified representation of the neighbouring British system including proposed wind capacity and interconnectors between the two systems. The level of wind curtailment is determined under varying levels of three influencing factors. The first factor is the amount of offshore wind, the second is the allowed limit of system non-synchronous penetration (SNSP) and the third is inclusion or exclusion of transmission constraints. A binding constraint, resulting from the 2020 EU renewable energy targets, is that 37% of generation comes from wind. When the SNSP limit was increased from 60% to 75% there was a reduction in wind curtailment from 14% to 7%, with a further reduction when the proportion of wind capacity installed offshore was increased. Wind curtailment in the range of SNSP limit of 70-100% is influenced primarily by the inclusion of transmission constraints. Large changes in the dispatch of conventional generators were also evident due to the imposition of SNSP limits and transmission constraints. Mon, 01 Jul 2013 00:00:00 GMT http://hdl.handle.net/10468/1010 2013-07-01T00:00:00Z http://hdl.handle.net/10468/887 Typical tropospheric aerosol backscatter profiles for Southern Ireland: The Cork Raman lidar McAuliffe, Michael A. P.; Ruth, Albert A. A Raman lidar instrument (UCLID) was established at the University College Cork as part of the European lidar network EARLINET. Raman backscatter coefficients, extinction coefficients and lidar ratios were measured within the period 28/08/2010 and 24/04/2011. Typical atmospheric scenarios over Southern Ireland in terms of the aerosol load in the planetary boundary layer are outlined. The lidar ratios found are typical for marine atmospheric condition (lidar ratio ca. 20–25 sr). The height of the planetary boundary layer is below 1000 m and therefore low in comparison to heights found at other lidar sites in Europe. On the 21st of April a large aerosol load was detected, which was assigned to a Saharan dust event based on HYSPLIT trajectories and DREAM forecasts along with the lidar ratio (70 sr) for the period concerned. The dust was found at two heights, pure dust at 2.5 km and dust mixing with pollution from 0.7 to 1.8 km with a lidar ratio of 40–50 sr. Fri, 01 Feb 2013 00:00:00 GMT http://hdl.handle.net/10468/887 2013-02-01T00:00:00Z http://hdl.handle.net/10468/888 Analysis of an 18O and D enhanced water spectrum and new assignments for HD18O and D218O in the near-infrared region (6000–7000 cm−1) using newly calculated variational line lists Down, Michael J.; Tennyson, Jonathan; Orphal, Johannes; Chelin, Pascale; Ruth, Albert A. An experimental infrared spectrum due to Orphal and Ruth (2008) [10] recorded using isotopically enriched water in the 6000–7000 cm−1 region is analysed and assigned. The assignment procedure is based on the use of known transition frequencies for H216O and H218O, existing variational line lists for HD16O and D216O, and newly calculated variational line lists for HD18O and D218O. These new variational line lists are presented herein. The main absorption comes from HD16O and HD18O, for which there are few previous assignments in the region. Assignments to 426 new HD18O lines are presented. In all 3254 of the 4768 lines observed in the spectrum are assigned, resulting in a number of newly determined energy levels. These assignments are in agreement with the recent work of Mikhailenko et al. (2012) [41]. Sat, 01 Dec 2012 00:00:00 GMT http://hdl.handle.net/10468/888 2012-12-01T00:00:00Z http://hdl.handle.net/10468/707 The effect of introducing a winter forage rotation on CO2 fluxes at a temperate grassland Leahy, Paul G.; Kiely, Gerard Temperate grasslands have the potential to sequester carbon, helping to mitigate rising atmospheric CO2 concentrations. The ability of grasslands to absorb CO2 is influenced by site elevation, soil type, management practices, climate and climatic variability. There is a need for long-term observations and field experiments to quantify the effects of the key drivers of management and climate variability. This paper presents over 4 years of eddy covariance measurements of CO2 flux over a managed temperate grassland site in south-east Ireland. For the first 2 years the entire study area was under grass. During the second 2 years a winter forage crop was grown over part of the site. The site was found to have a net uptake of CO2 during all years. However, the magnitude of the CO2 uptake varied considerably from year to year, with a maximum net uptake of 1.32 kg CO2 m−2 in 2004, a year with no winter forage crop. Net uptakes were much lower in the 2 years of mixed grass and kale cultivation, but detailed analysis of the measurement footprint and statistical comparisons showed that this was not due to the introduction of the forage rotation. For a short period following sowing of the forage crop, daytime CO2 uptake was less than that of the area under grass, but over subsequent months daytime CO2 uptake of the kale areas recovered strongly and exceeded that of the grass areas. The net effect over the year following kale planting is close to CO2-neutral. Wed, 01 Aug 2012 00:00:00 GMT http://hdl.handle.net/10468/707 2012-08-01T00:00:00Z