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39% of America's Energy Could One Day Be Generated by Rooftop Solar Panels

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istock

The answer to America’s energy problems could be right under our noses—or, rather, right over our heads. According to a recent study by the Energy Department’s Renewable Energy Laboratory (NREL), America’s rooftops are full of untapped potential. In fact, up to 39 percent of America’s energy could be generated just by installing photovoltaic (PV) solar panels on urban rooftops.

Popular Science reports that NREL analyzed rooftops in 128 cities across the United States, representing about 23 percent of all buildings in the U.S., according to an NREL press statement. The researchers assessed the buildings' suitability for hosting PV solar panels and measured how much power could be generated by each location. They found that 83 percent of small buildings had the technical potential to host PV panels on part of their rooftop areas, while 26 percent could host an entire rooftop’s worth of panels.

Researchers say that their findings far exceeded previous estimates of the amount of power that could be generated by rooftops alone. Their analysis estimates that rooftops have a technical potential of 1118 gigawatts of capacity and 1432 terawatt-hours of annual energy generation, which would equal 39 percent of America’s total electricity sales (based on 2013 numbers).

However, it’s important to note that researchers analyzed technical potential only. That is, they considered resource availability and the availability of space without also analyzing economic or political factors—which means that while America may have the space for rooftop solar panels, it may not currently have the political will or a plan of action.

"An accurate estimate of PV's technical potential is a critical input in the development of regional deployment plans," explains researcher Pieter Gagnon. "Armed with this new data, municipalities, utilities, solar energy researchers, and other stakeholders will have a much-improved starting point for PV research and policymaking, both regionally and nationwide."

[h/t Popular Science]

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Michael Gottschalk, AFP/Getty Images
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environment
Germany Wants to Fight Air Pollution With Free Public Transit
Michael Gottschalk, AFP/Getty Images
Michael Gottschalk, AFP/Getty Images

Getting people out of their cars is an essential part of combating climate change. By one estimate, getting people to ditch their two-car household for just one car and a public transit commute could save up to 30 percent in carbon dioxide emissions [PDF]. But how do you convince commuters to take the train or the bus? In Germany, the answer may be making all public transit free, according to The Local.

According to a letter from three of Germany's government ministers to the European Union Environment Commissioner, in 2018, Germany will test free public transit in five western German cities, including Bonn. Germany has failed to meet EU air pollution limits for several years, and has been warned that it could face heavy fines if the country doesn't clean up its air. In a report from 2017, the European Environment Agency estimated that 80,767 premature deaths in Germany in 2014 were due to air pollution.

City officials in the regions where free transport will be tested say there may be some difficulty getting ahold of enough electric buses to support the increase in ridership, though, and their systems will likely need more trains and bus lines to make the plan work.

Germany isn't the first to test out free public transportation, though it may be the first to do it on a nation-wide level. The Estonian capital of Tallinn tried in 2013, with less-than-stellar results. Ridership didn't surge as high as expected—one study found that the elimination of fares only resulted in a 1.2 percent increase in demand for service. And that doesn't necessarily mean that those new riders were jumping out of their cars, since those who would otherwise bike or walk might take the opportunity to hop on the bus more often if they don't have to load a transit card.

Transportation isn't prohibitively expensive in Germany, and Germans already ride public transit at much higher rates than people do in the U.S. In Berlin, it costs about $4 a ride—more expensive than a ride in Paris or Madrid but about what you'd pay in Geneva, and cheaper than the lowest fare in London. And there are already discounts for kids, students, and the elderly. While that doesn't necessarily mean making public transit free isn't worth it, it does mean that eliminating fares might not make the huge dent in car emissions that the government hopes it will.

What could bring in more riders? Improving existing service. According to research on transportation ridership, doing things like improving waits and transfer times bring in far more new riders than reducing fares. As one study puts it, "This seldom happens, however, since transport managers often cannot resist the idea of reducing passenger fares even though the practice is known to have less impact on ridership."

The same study notes that increasing the prices of other modes of transit (say, making road tolls and parking fees higher to make driving the more expensive choice) is a more effective way of forcing people out of their cars and onto trains and buses. But that tends to be more unpopular than just giving people free bus passes.

[h/t The Local]

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Animals
Watch an Antarctic Minke Whale Feed in a First-of-Its-Kind Video
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WWF

New research from the World Wildlife Fund is giving us a rare glimpse into the world of the mysterious minke whale. The WWF worked with Australian Antarctic researchers to tag minke whales with cameras for the first time, watching where and how the animals feed.

The camera attaches to the whale's body with suction cups. In the case of the video below, the camera accidentally slid down the side of the minke whale's body, providing an unexpected look at the way its throat moves as it feeds.

Minke whales are one of the smallest baleen whales, but they're still pretty substantial animals, growing 30 to 35 feet long and weighing up to 20,000 pounds. Unlike other baleen whales, though, they're small enough to maneuver in tight spaces like within sea ice, a helpful adaptation for living in Antarctic waters. They feed by lunging through the sea, gulping huge amounts of water along with krill and small fish, and then filtering the mix through their baleen.

The WWF video shows just how quickly the minke can process this treat-laden water. The whale could lunge, process, and lunge again every 10 seconds. "He was like a Pac-Man continuously feeding," Ari Friedlaender, the lead scientist on the project, described in a press statement.

The video research, conducted under the International Whaling Commission's Southern Ocean Research Partnership, is part of WWF's efforts to protect critical feeding areas for whales in the region.

If that's not enough whale for you, you can also watch the full 13-minute research video below:

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