Since its establishment, Mt Stromlo has had policies around both the environment and lighting to allow us to do our work and keep the skies as relatively dark as possible. While the necessity of this may have stopped or been reduced with the 2003 fires, in the past 5 years, Omexom, who manages and operates the lighting infrastructure in Canberra, have been aiming to reduce light spill and the carbon footprint of the city. The ACT lighting network is being upgraded to both better and more efficient lights (LEDs) with 60% of luminaire now upgraded. The new luminaire are able to be individually controlled and have a custom power/wattage output. We have been trialing reducing the overall lighting of Canberra at various levels, and measuring the impacts on sky glow, sky brightness, as well as the energy and subsequent CO2 emission savings. We will present the system, experiment, and results from this as well as where to next - both in Canberra and as a model for other cities across the world.