In the middle of the night, it's not uncommon to find hundreds, maybe thousands of city streetlights lighting up the night sky in any city. They are inherently necessary for the safety of pedestrians and passengers of vehicles. But because traffic is far less dense while most people are tucked in their beds, a lot of energy is wasted at night. Fortunately, new innovations in streetlight technology are helping to change that.

Several European cities, which are often riddled with blackouts, have already launched pilot testing programs for smart streetlamps in an effort to conserve energy and reduce carbon emissions. Smart streetlights, designed by the Netherlands' Delft University of Technology, utilize motion sensor technology to determine if pedestrians or vehicles are nearby. If there is no street activity, these intelligent streetlamps can dim to 20 percent power.

When a person or car approaches a streetlamp it ramps back up to 100 percent power to fully light the area. The lights are also wirelessly linked to one another, so if one light senses activity all of the nearby lights will return to full power. Once activity has died down, the devices will dim again. The same sensor will notify a central control center when it needs maintenance.

The technology also has the capability to differentiate between people and animals. So if a stray cat ambles down a street, it won't signal the lamps to turn on unnecessarily.

Each year, Europe spends $13 billion powering its streetlights — an amount that represents 40 percent of government energy bills, according to the Christian Science Monitor. In terms of carbon emissions, streetlights in Europe cause 40 million tons of carbon dioxide emissions every year, the equivalent amount of emissions caused by 20 million cars.

Many cities have seen this as an opportunity for improvement and have turned toward energy-saving lighting options. Four cities in the Netherlands and one in Ireland have already started utilizing Delft University's smart streetlamp model. The system is said to decrease emissions by 80 percent while reducing the cost of light pollution and maintenance.

Chintan Shah, the inventor of these devices, says the system will pay for itself in as little as three years because of the energy savings investors will see. On top of the diminished costs of lighting the streets at night, Shah says smart streetlights can save up to 50 percent in maintenance expenses compared to traditional streetlights.

Other cities in Europe are working to develop their own smart streetlamps. Copenhagen plans to have 20,000 smart streetlamps on the grid in 2014, while similar efforts are also underway in Finland.

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