It's hard to accurately predict how much power we can generate from the sun. You can't simply plop solar panels down everywhere; only some surfaces work. To figure out exactly how much solar capacity New York City has, scientists have created an interactive map showing where panels could be installed. And they did it with lasers.
The New York City Solar Map , created by the City University of New York (CUNY ) shows that two-thirds of the city's rooftops could be used to generate solar power based on their angle, shape, and shading from surrounding structures and trees. In fact, New York City has enough solar capacity on its roofs to power half of the city during periods of peak demand.
The map was made possible thanks to lasers--or more specifically, Light Detection and Ranging (LiDAR ) data taken from laser-equipped plane flyovers. LiDAR--a technology that shoots down laser pulses and measures the amount of time that it takes for them to bounce back--is also used to map forests, optimize wind farms (by measuring wind speed and turbulence), and even for adaptive cruise control systems, which use the technology to measure the distance between cars.
We decided to test the solar map on Fast Company's headquarters at 7 World Trade Center. This was the result:
Upon clicking the "Get Site Details" button, we also learned that the building has 14,693 square feet available for solar installations, and it could accommodate a 161 kW solar system on the roof. (We'll ask the landlords.)
In total, the map shows that New York could generate up to 5,847 megawatts of solar power--but today, city rooftops only generate 6.6 megawatts from just 400 installations.
Ramping up installations won't be easy or quick. Installation costs can run upwards of $10,000 (though solar leasing companies like SolarCity  take care of that problem), and utilities are still learning how to adapt to having large amounts of intermittent renewable energy sources on the grid.
But past evidence indicates that just having a citywide solar map makes a difference. After San Francisco launched its solar map , the number of solar installations on private roofs shot up from 551 in 2007 to 2,300 today, according to the New York Times . So it's entirely possible, then, that lasers may just help launch a solar revolution in the Big Apple.