Talking about all things energy, from clean tech, to biofuels, and policy.

Southern Heat Strains Power Generation

The heat this summer has been extraordinarily intense in many Central and Southern states, and triple-digit temperatures continue to roast parts of Texas, Oklahoma, and Arkansas. For example, Dallas, Texas is closing in on its record for the longest streak of 100°F days, and similar milestones have already been reached in other parts of the Lone Star state. At 88.9°F, the average temperature in Oklahoma during the month of July set a new record for the all-time warmest calendar month for any state in the US during any month. 

Perhaps not surprisingly, this unrelenting warmth is putting a strain on power generation in several areas. During warm weather like this, the demand for electricity peaks with the highest temperatures, as people rely more on air conditioning to keep cool. In order to meet the extra demand during hot weather, power companies typically have to boost their electricity output.

The cruel twist is that, by affecting power plant cooling systems, the persistent heat can also hamstring electricity generation, and this has played out during the past few weeks in parts of the South.

Last week, the Tennessee Valley Authority was forced to cut power generation in half at their Browns Ferry nuclear power plant near Athens, Alabama.

A few months back, I wrote about the threat heat waves pose for nuclear power plants, and Browns Ferry in particular. Nuclear plants draw in water from nearby rivers or lakes for cooling purposes, but they face...

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Interactive: Powering the Nation with Wind

By David Kroodsma

How much electricity could the U.S. generate from wind turbines? The answer may surprise you. For example, Texas alone could provide more electricity using wind energy than the entire United States currently uses.

Click through this graphic above and you’ll see just how far we are from fully utilizing this vast resource. Only five states (Washington, West Virginia, Pennsylvania, Tennessee, and Utah) have installed more than one percent of their potential wind energy generation. As a nation, we’re using only about 0.2 percent of our country’s potential wind resource.

It's also clear where this resource lies: in the Great Plains. The top states for potential wind power are Texas (see above), as well as Kansas, Nebraska, South Dakota, Montana, North Dakota, a...

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Replacing Coal With Clean Energy — Let Me Count the Ways

Coal-fired power plants provide about 45 percent of U.S. electricity. To increase the percentage of electricity coming from clean energy sources, America will likely have to move away from coal. Credit: Cathy Haglund/flickr.

As I recently pointed out, Americans consume immense quantities of electricity each year. Depending on where you live, it might come from a coal or a gas-fired power plant, a nuclear plant, a hydroelectric dam, wind turbines or even solar panels. I must admit, though, that I have no idea where my electricity comes from (other than out of the wall). But since I live in central New Jersey, my electricity probably comes from both coal, gas, and nuclear power plants.

For the country overall, the relative proportions of each type of electricity have stayed constant for about the past 15 years:

  • Coal and natural gas produce 70 percent of our electricity
  • Nuclear power generates about 20 percent
  • Renewable sources (like wind and hydropower) provide about 10 percent.

Now, it looks like those proportions could be about to change.

During the 2011 State of the Union address, President Obama announced a new U.S. energy target: produce 80 percent of electricity from clean energy sources by 2035. Burning coal and natural gas to generate electricity releases billions of tons of heat-trapping carbon dioxide (CO2) gas into the atmosphere, so switching to more “clean” energy sources would help curb a lot of America’s greenhouse gas emissions, which are partly responsible for warming the climate.

So where is all this “clean energy” going to come from? To start with, Obama’s plan counts natural gas as “clean,” since even though it produces CO2, the emissio...

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Interactive Map Compares States’ Renewable Energy Goals

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...

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Mapping US Tidal Power Potential

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...

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