New York City holds data on the annual residential electricity use of every zip code in the city, a dataset that indirectly reflects where the big consumers live, where the building stock could be more efficient, and where the cost of utility bills falls the heaviest on low-income households.
Stick all that data on an interactive map, and it looks something like this, the Energy Zip web app from a group of NYU astrophysicists (no, there is no direct connection here to astrophysics; these guys have done this open-data project in their spare time). Jonathan Roberts, Jeff Allen and Ronnie Jansson are hoping that New Yorkers will also share some of their own electricity data with the site so that they can calculate some more fine-grained data on where energy use fluctuates the most between summer and winter (suggesting hot spots where neighborhoods could become more efficient).
For now, though, they're able to map residential electricity use per person (left) and per household (right), by zip code.
A few neighborhoods on the Upper East and West Sides of Manhattan are using more than 5,000 kilowatt hours of electricity per person, per year, compared to less than 1,500 kilowatt hours in purple pockets of the city. But some of that difference has to do with the size of households rather than the size of their energy bills. Those Manhattan zip codes include more single-person households, the outer boroughs larger families. Energy use spreads out more evenly across the city in the second map, at right, measuring per-household electricity use.
There's one notable exception, though: Roosevelt Island.
"When we saw that, we thought 'this is ridiculous, this must be an error in the data,'" Roberts says. In fact, though, unlike most of the rest of New York City, homes on Roosevelt Island primarily use electricity for winter heating, rather than gas or oil.
The map below at left shows the percentage of median income by zip code devoted to electricity use, with homes in the Hunts Point and Mott Haven neighborhoods of the Bronx devoting 9.3 percent of their pre-tax income to the utility. In most of the rest of the city, that share is closer to 1 or 2 percent.
"That’s effectively a 7 percent regressive tax on the people of Hunts Point and Mott Haven just from their electricity, which is remarkable," Roberts says.
Those Bronx neighborhoods would be the most logical place for the city to target residential energy tax credits that help residents install renewable energy sources. The map at right, however, shows where those credits have been used, per household. For various reasons, likely having to do with outreach about the program and the cost of installation, the city's residents most in need of utility relief, and the buildings that could most use an energy retrofit, may not be getting them. At least maps, though, can help reveal that.
All images courtesy of energyzip.org.