The highly anticipated Chevrolet Volt is getting ever closer to the showroom floor. Whether you think of it as an electric car or a plug-in gasoline-electric hybrid, the Volt represents a significant step forward for mass-produced fuel-efficient cars. 

The Volt is different than other hybrids on the roads today in that it uses electricity as the sole means for powering the car; the gasoline engine works only to recharge the car’s lithium-ion battery pack. GM estimates that the Volt will travel up to 40 miles without using a single drop of gasoline, more than enough to cover the average American’s commute to work. Recharge your Volt while at work and you’d then be able to drive home without burning any gasoline. If recharged via a renewable energy source, the car’s power would be entirely emissions-free. 

You can learn more about the Volt in The Volt: An Electric Car That Could Change Everything and Update: The Chevy Volt, the Electric Car of the Future. 

Last week, GM vice chairman Bob Lutz appeared on The Late Show with David Letterman to talk about the Volt. Letterman recently purchased a Tesla Roadster, an all-electric car that gets more than 200 miles per charge, and previously said that the Volt’s 40-mile capability was “crap.” (You can watch Lutz and Letterman’s exchange below.) 

When asked why GM couldn’t make a car with performance comparable to the Tesla, Lutz replied that GM needs to sell cars at volume, and thus needs to give the Volt a practical price tag. Lutz then said that when the Volt hit dealerships in late 2010, it would cost about $40,000 (the Tesla sells for more than $100,000). 

But the first 200,000 Volts Chevrolet sells will be eligible for a federal tax credit of $7,500, bringing the final price to about $32,500. 

So, what do you think? Would you pay $32,500 to $40,000 on an electric vehicle such as the Volt? What if gas prices rise back up to $4 a gallon, or more? Share your thoughts by posting a comment below.

New York Gov. David Paterson recently announced a plan to increase the state’s use of solar power.  Paterson wants the state to install up to 100 megawatts of solar photovoltaic power systems at public and private facilities such as schools and municipal and commercial buildings. According to the New York Power Authority, 100 megawatts could power approximately 15,000 homes.  

The initiative is part of New York’s 45-By-15 energy plan, which aims to have the state running on 45 percent efficient and clean renewable energy sources by 2015. Here’s a link for more information on New York’s energy initiatives.

Also, find out what other states have similar plans to move toward using renewable energy sources.

Hold onto your hats, Congress is debating climate change. Right now the U.S. House is considering the Waxman-Markey climate bill.

To get in on the fun, check out the extensive coverage over on Grist. You can find their latest articles on the climate bill here. (One especially fun article: Grist’s description of Gore v. Hansen on the climate bill, complete with an illustration showing those two environmental heavyweights boxing.)

Also today, I was reading an e-mail update from the American Solar Energy Society. They had a short and helpful summary of why they believe that the climate bill isn’t strong enough and what could be done to improve it. Here’s a link to their recommendations.

Many people dream about powering their homes with solar energy, but aren’t ready to make the investment in solar panels just yet. But chances are you’re already using solar power at home, even if it’s only in a small way.

There are a growing number of small, inexpensive solar-powered gadgets available that fit nearly every budget. That includes not only the familiar solar calculator, but a growing array of solar flashlights, radios, cell phone chargers, outdoor motion lights and more. Solar-powered products also are useful around the homestead, for example, for solar-powered electric livestock fencing.

Over the last couple of weeks, we ran a poll asking people if they were using these small solar-powered products and a surprisingly large number of people —almost 90 percent — said yes!

Now we’d like to know more about what you think of these solar gadgets, including what products you’re using and why — or why not. For example, do you have a solar cell phone charger or radio around because it’s a good backup for emergencies? Are you using solar motion lights because they’re convenient? Do they save you money?

Beyond that, what do you think about these small solar products in general? Are they gimmicky? Interesting? Useful?

Share your thoughts by posting a comment below.

I always enjoy watching videos from the TED website. Here’s an interesting one on tapping wind energy with kites. The idea is that kites have the potential to get much higher up in the air than even the largest wind turbines, so they’re a good tool for tapping into the large amount of wind power found at high altitudes.
 

This week, NPR has been running a series called Power Hungry: Reinventing the U.S. Electric Grid. There’s a whole lot of good information there about renewable energy and the need for improvements to the grid in order to get wind and solar power into our homes. You can find the whole series at the link above.

Or, for one quick highlight, here’s a link to one great graphic on Visualizing the Grid. This map shows just about everything you might want to know about electricity in the United States. What does the grid look like now? Where are new power lines being proposed? Where are the best solar and wind resources? Take a look and find out.

In my last blog, I noted that vertical axis wind turbines (VAWTs) leave much to be desired. My point was that these designs, which have been around for thousands of years, just haven’t panned out. Buyer beware: they’re not all they’re cracked up to be (See An Open Letter-To inventors of Vertical Axis Wind Turbines and Rooftop Wind 'Technology Breakthroughs'.) I wasn’t trying to discourage people from tinkering with them, but I was trying to warn folks who think they’re going to be making a wise investment from buying one.

Many of you posted comments to the contrary, either accusing me of stomping on the dreams and aspirations of young inventors or simply not knowing what I was talking about. Some readers accused me of making baseless claims without any science to back up my assertions.  Let me provide some more information on VAWTs.

While many modern VAWT inventors show videos of their turbines spinning, which convince news organizations and potential buyers of their value, it’s not spinning blades that matter. What matters is energy output. Because wind speeds are low at ground level, VAWTs won’t produce much energy — nowhere near as much useful energy as a well placed horizontal axis wind turbine. That’s why horizontal axis wind turbines are the technology of choice for most applications. 

The main reason that wind speed is so low at ground level is ground drag. Ground drag is caused by friction when air flows across a surface. Friction is the force that resists movement of one material against another.

When wind flows across land or water, friction dramatically reduces the speed with which wind flows over land.  Ground drag due to friction varies considerably, depending on the texture or roughness of the surface. The rougher or more irregular the surface, the greater friction.  As a result, air flowing across the surface of a lake encounters less friction than air flowing over a meadow. Air flowing over a meadow encounters less friction than air flowing over a forest.

Interestingly, friction slows wind speed to a height of about 1,650 feet above the Earth’s surface. However, the greatest effects are closest to ground — the first 60 feet (20 meters) above the ground over a relatively flat, smooth surface. 

The effect of friction is quite profound. A 20-mile-per-hour wind measured at 1,000 feet above the surface of the ground covered with grasses, flows at 5 miles per hour at 10 feet — where most VAWTs are located. It then increases progressively until it breaks loose from the influence of the ground drag or friction at around 80 feet.

Because the effects of friction decrease with height above the surface of the Earth, savvy installers typically mount their wind machines on towers 80 to 120 feet (24 to 37 meters). This removes them from the influence of energy-robbing ground drag. At these heights, the winds are substantially stronger than they are near the ground.

Savvy installers also avoid suburban and urban environments because the surface texture is quite rough in these areas. Trees and buildings dramatically lower annual average wind speeds. They also create a lot of turbulence and eddies — pockets of relatively dead air. Place any turbine in this environment and you can expect significantly reduced energy production.

I like the looks of a lot of VAWTs and wish inventors success, but don’t lose track of the fact that there’s very little energy in ground-level winds during a given year. In fact, a recently published study of wind turbines mounted on buildings in England showed that many turbines failed miserably when it came to energy output. Average wind speed at these levels were just too low to produce a significant amount of electricity. The inverters in many of these systems consumed more energy than the wind turbines produced in a year. See the results of the Warwick Wind Trials.

When you invest in a wind turbine, you want energy output. It’s not spinning blades, but electricity that most of us want — and lots of it — to make our investment worth the while.

Power available from the wind is a function of the wind speed cubed. If the average annual wind speed is low, which it is at ground level or even on the roofs of homes, you just won’t get much energy from a turbine — any kind of turbine. (See Rooftop Wind-Determining Your Resource.) Mounting a turbine at ground level places it in much weaker winds at most locations. It is a bit like mounting solar panels in the shade! NREL’s wind energy expert Jim Green says, “For a given swept area, VAWTs just don’t extract quite as much wind energy as a well-designed HAWT.” 

I’d be happy to be proven wrong. Show me the data that indicates that a ground-level or even a roof-top turbine of any sort produces a sizeable amount of electricity during a year!

It is important to note that years of experience with VAWTS has been rather discouraging, to say the least. “Hundreds of commercial VAWTs were installed in California in the late 1980s and early 1990s,” according to energy consultant Bob Aram. “They all failed and were removed from service. These were not experimental units, but production units.”