Auto dimming street lights, can save an amazing amount of energy.
At highway 155 in Nes i Hole, 220 radars have been installed on each light pole. They detect oncoming traffic and adjust the strength of the light. By doing this, the 9 km/5.5 mi stretch saves a whopping 2100 kWh per week. The extra investment will break even after just 4.5 years.