Dark Sky Ireland Lighting Recommendations 13 February 2020 Public Lighting Recommendations A document prepared for the Road Management Office Prof. Brian Espey, School of Physics, Trinity College Dublin on behalf of the Dark Sky Ireland group Promoting and preserving Ireland's Dark Skies 1 Dark Sky Ireland Lighting Recommendations 13 February 2020 Prof. Brian Espey, School of Physics, Trinity College Dublin on behalf of the Dark Sky Ireland group https://www.darksky.ie/ Contact info: email:
[email protected] Ph: (01) 896-2680 13th February 2020 2 Dark Sky Ireland Lighting Recommendations 13 February 2020 Abstract Public lighting accounts for €56 million in public expenditure annually and is a major item in council budgets. A large proportion of the 480,000 units in the lighting stock are in need of replacement with more efficient luminaires in order to meet energy and carbon reduction targets. The following document is predicated on the assumption that LED lighting will be increasingly used for public lighting and aims to mitigate the negative effects within the constraints of the drive for energy efficiency and lower carbon production. It is important to point out, however, that in line with the recommendations of bodies such as the Institution of Lighting Professionals the greatest savings will be made by dimming lights or removing unnecessary lighting. This document outlines aspects of public lighting in relation to the installation of LED lighting and the desirability to reduce both light levels and the blue spectral component. LED technology is known to have positive outcomes in terms of economic and environmental aspects (including carbon dioxide reduction) and the replacement of older lanterns with modern full cut-off designs which reduce or eliminate light emission above or near the horizontal provide further gains.