Low Carbon Lighting


We started our lighting project in 2003 in partnership with lighting engineer Richard Hayes. We agreed that street lighting presented a large forward opportunity and we proceeded to read the research papers by Sam Berman published by Berkley University. Berman’s paper has profound implications for low carbon lighting. Most European and North American lighting levels are predicated upon Photopic instruments and sensitivity. Berman’s experiments challenge this fundamentally. Berman exposed his subjects to a procedure of seeing objects out of darkness under the light of differing lamp technologies and established that Scotopic Sensitivity was of greater importance under these conditions than Photopic Sensitivity. After reading these and other related research papers we concluded with Richard that if this was correct, then the low carbon opportunities were immense. We agreed to finance a lighting trial in the City of Leicester to test the research. The trial, the first worldwide was measured by the Institute of Energy and Sustainable Development at DeMontfort University. The DeMontfort University campus embracing a city centre public highway was used for the lighting trial. The Gateway is illuminated with 150 watt high pressure sodium lights casting a typical orange – yellow glow and acts as a “project constant”. We installed our experimental luminaires housing 70 watt CDMT white light lamps to Mill Lane to establish a clearly visible contrast of lamp technologies and wattages. The research team published their results of the human response surveys in March 2006. The documentation is emphatic. We can cut street lighting electricity costs and C02 by 50% or more. The implications of this are relevant to Cities worldwide.