Mapping New York's Solar Potential with Lasers!

For a city of people obsessed with using every last inch of real estate efficiently, New York has been neglecting a wealth of empty space—its rooftops. The occasional green roof or patio aside, most of the city’s roofs are covered in black tar, which does nothing more than collect heat and keep the city hotter than it needs to be. The Bloomberg administration, however, thought the city’s rooftops could be doing so much more. The Mayor’s Office of Long-Term Planning Sustainability, along with a few partners, commissioned a plane to fly over the city and capture its every contour with a system of lasers. The result: a map of the city that shows how much energy every single rooftop could be generating, if it had solar panels installed.

If the city’s solar potential were realized, the study showed, New York City could get half of the electricity it needs at peak times from rooftop installations.

The solar map is also a crowd-sourcing tool that allows businesses and residents to add their solar system and leave testimonials. Most cite both worry for the environment and cost savings as motivations for investing in a system and some brag about their tiny electric bills. One family says their bills have not gone higher than $19 per month since they installed the panels. Others rail against ConEdison, the primary electricity provider in the city, and its high prices.

ConEdison is actually happy to see at least some of its customers go solar. It has worked with the NYC Solar America City Partnership to create Solar Empowerment Zones in Staten Island and in Brooklyn. The city is targeting these areas for solar installation; right now, the city will give solar owners in those zones free data monitors to track their energy generation, for instance. These zones are all places where energy use is looking to scale up in the future: The more solar power installed here, the less pressure there will be on Con Edison to build more generation plants to serve these areas.

But the current population of solar power systems on the map is somewhat sparse. The map doesn’t claim to be an exhaustive survey on solar panels in the city, but I counted just two government, nine commercial, and 22 residential projects in Queens, which had more projects than any other borough.

In San Francisco, solar installations jumped after a solar survey in 2007 created a similar map. Solar might be a harder sell in New York, though, a city of apartment dwellers with less investment in the infrastructure of their building. Take my building, for example. According to the solar map, 335 square feet of my rooftop are suitable for solar. But installing solar panels there would save only $629 each year. With twenty apartments in my building, that’s about $31 for each household. None of us have an incentive to push our landlord to install a solar system. In the past, landlords haven’t had an incentive to install green improvements, either: They don’t benefit from reducing their tenants’ electric bills.

The Bloomberg administration has been working to change that. A few months back, they released a new type of lease that would allow landlords to earn back their investments in green improvements like solar panels more quickly. But the alternatives—rising electricity prices, more frequent brown-outs or black-outs—might convince more tenants and landlords that it’s in everyone’s best interest to put our rooftops to work.

Picture courtesy of NYC Solar American City