By Matt Zonis
Sun, water, waves, wind… no this isn’t the beginning to an episode of Captain Planet or a tour of power plants in Orbit City courtesy of George Jetson, but real sources of energy that are being harnessed and used to greater or lesser extent today. While it’s true that we still heavily rely on fossil fuels, renewable energy is on the rise, now accounting for almost 10 percent of US electricity generation. This number is only expected to increase, in part due to rising demand for renewable electricity from individual states in the absence of a national mandate. For many reasons, including a goal of encouraging economic development and the growth of the clean tech sector, many states have taken it upon themselves to increase their use of renewable energy by implementing policies known as Renewable Portfolio Standards (RPS).
Simply put, an RPS is a goal set by an individual state that requires that a certain percentage of electricity sold to customers within that state be produced by renewable sources by a specified year. Currently, 36 states have an RPS. For instance, in Haw...
When I was young, I lived just a couple minutes from the ocean, and during the summer I went to the beach almost every day. Sometimes there was nothing more than a few yards of rocky shoreline exposed. At other times, when the tide was out, the smooth stones gave way to rippled sand that stretched over a half mile out to the horizon. Those were the best days, when my brother and I had time to collect sand dollars, dig for clams, and build sand castles. Eventually, the tide would change, and the water would start its journey back towards the rocks.
In places like Puget Sound in the Pacific Northwest, strong tidal currents could be harnessed to generate electricity. Credit: mikeyskatie/flickr.
Even though the incoming water could swallow up a sandcastle in mere minutes, I never thought of the tide as being powerful. But in some places, like Puget Sound in the Pacific Northwest, a changing tide can send water rushing through channels so narrow that it picks up incredible speed. In fact, this tidal water flow can be so powerful that its energy might someday be harnessed to generate electricity, just like water that flows through a hydroelectric dam on a river.
No power stations that use tidal power have been built in the U.S. yet (though several countries, including France, Canada, and South Korea, have operational stations), but there is growing interest in the idea of undersea turbines that capture this renewable energy source. The Department of Energy (DOE) has funded several tidal power test projects, and numerous international companies have recently been testing their turbines in places like S...
By Ruthie Nachmany
When Audrey Zibelman paints a picture of what an energy-efficient city might look like, she imagines a young woman, fresh out of college, who has come to Zibelman's home city of Philadelphia for her first job. In a rush to get to work one morning, the woman remembers too late that she left the lights on in her apartment—but that's no problem: she can use her iPhone app to switch the lights off remotely. She hops on a commuter train that runs on electricity; every time it stops, an on-board system recaptures some of the train's energy of motion, much like a Prius does. When she gets off the train, she gets a text message from the transport company, thanking her for saving energy. As she enters her new office in a LEED-certified energy efficient building, the lights turn on automatically to her preset preference (they'll turn off automatically when she leaves the room), and the temperature automatically sets to her comfort. She looks out the window at the skyline, dominated by other green buildings. She thinks to herself, “This is a cool city.”
At a recent Philadelphia conference on improving energy efficiency in America's cities, presenters discussed how personalizing power, with iPhone apps for example, will help reduce energy consumption. Credit: Yutaka Tsutano/flickr.
Zibelman painted her picture of the near future again last month, when she spoke at the America’s Sustainable Future conference in Philadelphia. Zibelman is the founder and CEO of Viridity Energy, a company that helps people and businesses increase their energy efficiency. Her goal was to begin a conversation among local energy innovators about how their community is trying to get smart about...
The International Energy Agency issued a new report today that asks, and then answers, this question: "Are We Entering a Golden Age of Natural Gas?" You can download the 131-page document if you like, but the bottom line is (spoiler alert!): yes. However, it's important to understand that the authors' analysis is based on a set of assumptions that may or may not end up being true.
But assuming they're right, what does "golden age" really mean in this context? If you think it means we're going to enter some sort of golden age because of natural gas, think again. What the report actually says is that natural gas itself may about to experience a golden age — meaning we could be using more of it in the next few decades than we do now. By 2035, it says, natural gas could make up 25 percent of the world's energy supply. Natural gas already makes up 21 percent of our energy mix, so the difference between the upcoming golden age and the present age might not look all that significant.
A worker checks the valve of a gas pipe at a natural gas plant in Suining, in southwest China's Sichuan province on November 15, 2010. Credit: STR/AFP/Getty Images.
Still, that would represent a 50 percent increase in how much natural gas the world consumes (it doesn't change the overall percentage much because there will be growth in other energy sources as well). So it's good news if you're in the natural-gas business. There are a couple of reasons why natural gas might gain in market share compared to other energy sources. First, there's lots of it, and, unlike oil, it's spread relatively evenly around the world. Second, new drilling tec...
In their new June 2011 issue, Scientific American magazine has published a story investigating the safety of the newest generation of nuclear power plants (a digital subscription is required for access). To accompany the story, the online team has produced a new interactive graphic available to everyone that pinpoints each of the 104 nuclear reactors across the United States (and the locations of 22 proposed new reactors).
Similar to the map Climate Central’s David Kroodsma produced in March 2011, immediately following the nuclear disaster at the Fukushima Daiichi facility in Japan, this new map compares the location of American plants to regions of high earthquake risk (Climate Central's interactive tracked the location of previous earthquakes).
Compiling reactor data from the Nuclear Regulatory Commission (NRC) and seismic hazard data from the U.S. Geological Survey (USGS), the SciAm graphic shows that there is already a handful of U.S. nuclear power plants located in earthquake-prone areas of the country. The threats aren't just to reactors in California and Washington State; some located in South Carolina, Tennessee, Arkansas and Missouri are also along the fringe of seismically active regions.
Earthquakes pose low probability but high consequence risks for American nuclear power plants — after all, scientists can’t always anticipate in advance when tremors will happen and how strong they will be. However, reactors built near fault lines are co...