Lighting the Way: Urban Energy Efficiency

When you're out in rural New Jersey, there's an easy way to find New York: look for the glow. While the rest of the sky will get dark, you will see two hazy, orange glows on the horizon. The brightest one is NYC, the other is Philadelphia. Lights are one of the defining features of an urban area. Can't see any stars? You must be in Manhattan. Or in Jersey City.

To some extent, there's good reason for this. You want sidewalks to be well lit, so people can travel with greater safety. Some places never shut down, and the burn of their electricity lets you know that they're open and waiting. But lots of it is simply light pollution: waste generated by our indifference to what the sum total of all that light is costing us. Or waste created on purpose, because as humans we are still fascinated by the shimmer of man-made stars.

Such is Paris, the City of Lights.

But even Paris is recognizing that the excesses of old need some rethinking. In June 2013, a California company named Silver Spring Networks teamed up with the city of Paris to embark on a program to modernize the old city's streetlights and traffic signals. The program is just a first step toward developing a smart grid throughout Paris.

Smart Grid

A smart grid is a complex web of utilities and infrastructure services that talk to each other and are able to respond in real time to changing conditions. Smart grids allow for two-way flows of energy. Currently, electricity flows from the power station to the consumer. But as solar panels become more popular, and energy more distributed, the grid will need to handle energy flowing back from consumers, as well. Smart grids can also be in direct communication with the systems inside buildings, such as the air conditioning, allowing them to automatically adjust temperatures to avoid spikes during high usage times. The high level of data gathering and communication done through such a system allows for increased efficiency and resiliency.

But the cost of such a system is high, which is why Silver Spring and Paris are starting with the lights. Street lights are already ubiquitous. Enabling them to report on their usage will, by necessity, create a communication network throughout the city's infrastructure, which can be leveraged for further smart grid uses later.

LEDs for Savings

The major upgrade to the lights themselves will be the switch to LEDs. New York City is already underway with its plan to replace all the street lights in the city with LED bulbs. They expect a 35% savings, which translates to $250,000 a year just for the 1,500 lights in Central Park. New York has over 300,000 fixtures total. They project a return on investment in 5 years, presuming that greenhouses gases have no monetary value.

Silver Springs projects even higher savings, near the 65% range, for Paris. The savings isn't entirely due to raw wattage from the bulbs, either. Maintenance costs drop dramatically, as LEDs are rated for 50k hours, compared to 10k for fluorescents. A smart streetlight can even report on its current lumen output, altering the city when it needs to be replacing without having to have anyone inspect it.

In Paris, the new LED system will also support auto-dimming. The European standards for roadway lighting define an illumination level based on cars per minute. As usage of the roadway drops, the lighting level requirement drops as well. The new system will be able to automatically dim the lights on used highways, lowering energy consumption.

While the United States has no such standards, it is an intriguing avenue to investigate. Perhaps Jersey City has some sections of highway that don't need as much light at 2 a.m. as they are currently getting. Even strictly directed lighting can save the city money, as less of it is required if you're ensuring that it's all going onto the ground where it's needed, instead of up into the air, washing out stars.

Given the success that New York is already seeing, it seems only natural to ask when Jersey City can start down this same path. The cost savings are only part of the benefit. The telecommunications network that would accompany the roll out would also be the start of a smart grid. As the energy usage of the city goes down, and distributed generation via solar goes up, a smart grid gives us the ability to avoid outages and recover from disasters faster. The convergence of these forces is where the future smart city is born: a partially self-sustaining, actively adjusted system that maximizes efficiency and uptime.

Before JC invests in more inventory to keep our old lights burning, it should start an exploratory project for making the switch.


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