Effektivare ytterbelysning inom Karlstads Bostads AB
This report is an inventory of the street lighting in half of the residential estates owned by Karlstad Bostads AB, a public housing company. The inventory was made to reduce the environmental impact of the street lighting. From the inventory an estimation of the total installed power and the energy consumption was made. The total estimated power of the street lighting was 125 kW and the energy consumption was 500 000 kWh/year with an estimated running time of 4 000 h/year. The dominating source of light was 125 W discharge mercury lamps. The largest potential to reduce the energy consumption of the street lighting was to replace the 125 W discharge mercury lamps by a substitute 75 W high pressure sodium lamps. This measure gave an estimated reduction of the energy consumption of 10 to 15 %. One other possibility for reducing the energy consumption was found when the control system for switching on and off the street lighting was checked. Many of the street lights were lit before the recommended limit value of the luminance, 5 lux occurred. If the control systems were adjusted the estimated reduction of the energy consumption would be 5 %. Aspects other than energy consumption are also of importance, such as tenants? opinions regarding safety and security.