If you’re interested in learning about wind power, there are a lot of resources available online, and I especially like checking out wind resource maps. There’s no faster way to get a quick look at wind power potential in your part of the world.

Two Fast Links to Wind Resource Maps

• Check out the wind power available on each continent with this collection of global wind power maps, which were produced by a study at Stanford.

• Take a look at U.S. wind power with these state wind resource maps from the U.S. Department of Energy.

Learning More with the Maps

All of these maps break wind resources down into wind power classes. For a quick look at how that translates into actual wind speeds, check out this helpful wind power classes chart from AWEA, the American Wind Energy Association.

A few other things that are helpful to keep in mind when thinking about wind power:

• Wind resource maps are just general guides. Different site-specific features (hills, trees, buildings, etc.) can make a significant difference in whether your property is a good location for wind power. (You can learn more about that with this small wind guide.)
  

• When you’re looking for the mightiest winds, remember that wind resources generally get better as you get higher off the ground. (Notice that the wind speeds on the maps and charts above are always listed for specific heights.)
  

• On this resource page from AWEA it specifies that in general, a wind power class of 4 or higher is currently preferred for large scale wind plants.
  

• A minimum wind speed may be required for grid-connected home wind turbines. This AWEA resource page also explains that average wind speeds of 5 meters per second (11 miles per hour) and above are generally required for grid-connected applications. Assuming a height of 10 meters, that's toward the upper end of Class 2 wind speeds.

Happy wind surfing!

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.”

Having a “green home” can mean all sorts of things. To some people, it means living in a home that’s free of chemicals or materials that produce any sort of toxic fumes (formaldehyde from furniture or volatile organic compounds from paint, for example).

To others, a green home must be extremely energy-efficient: superinsulated, energy-efficient appliances, and with minimal space. It may even include living off the electrical grid.

If a home isn’t built of natural, local materials (such as stone, logs, cordwood or adobe), some people will say it’s not green.

So, with all these variables in mind, what would be your fantasy green home? Tell us what it would be made of, what types of energy-conserving features it would have or about the design. You can write all about it in the comments section below.

Have you considered installing renewable energy systems at your home? For example would you be most likely to have a wind turbine, or solar electric panels? Have you thought about a solar water heater, a solar space heater or solar-powered outdoor lights?

Tell us what you’ve considered and why; whether you’re dreaming big or starting small; and how far in the future you hope to be able to make it happen.

If you’re looking for more information on your options, this article, All Kinds of Solar, is a quick list of the many different ways people use solar energy. Another good introduction to home-scale renewable article is the article Choosing Renewable Energy, which discusses one couple’s efforts to get off the grid with wind power, solar power and wood heat.

If you’re interested in the big picture of what’s happening in renewable energy, you’ll find a lot of interesting stuff at RenewableEnergyWorld.com. Check out their about us page for a quick list of links to more info on green jobs, breaking news and product descriptions.

Some of the information is very technical, but you can find basics too. Take a look at the Renewable Energy Technology Overview for background on solar, wind, geothermal and other renewable technologies. I also enjoy listening to the weekly podcast, Inside Renewable Energy.

Finally, there’s some interesting material from the Renewable Energy World Conference and Expo that took place in Las Vegas earlier this week. You can find video from the event here, or click here to go to the event’s blog.

PHOTO BY WARREN GRETZ/DOE/NREL

I have a couple of renewable energy calendars, and when you flip through them, you can’t help but notice a recurring theme. There are photos of wind turbines with photogenic cattle (or goats, or sheep) and glossy pictures of solar panels mounted on barns. All this is enough to start you thinking about renewable energy on the farm.

If you’ve ever wondered how farmers can benefit from renewable energy, check out this terrific page on farm energy from the National Sustainable Agriculture Information Service (otherwise known as ATTRA). The ATTRA site is full of practical information on sustainable agriculture, and they have a great collection of resources on renewable energy, including solar energy, wind energy, energy efficiency and biofuels.

What kind of information is covered? Well, you can read all about generating your own electricity with solar panels or wind turbines, the best solar greenhouse design, and methane recovery from animal manure (a subject which, understandably enough, I've never seen pictured on a calendar). Check it out!

BY BOJAN FATOR/ISTOCKPHOTO

I’d love to be able to say that my electricity comes from solar panels or a backyard wind turbine, but nope, I must admit, it comes from the grid. (My household does purchase green tags to offset our electricity use, but that’s another story.)

But here’s an interesting question: If your electricity comes from the grid, how can you find out what fuels it comes from? Different energy options have different costs and benefits. For example, is it possible that your utility gets some of its power from a wind farm? How about a nuclear power plant? How much of it comes from coal?

You can find out by using this nifty feature on the EPA web site. If you live in the United States, all you have to do is type in your ZIP code and identify your utility, and it gives you a couple of handy graphs and links that tell you which fuels the electricity comes from in your region, how that relates to pollution and how it compares to national averages.

When I typed in my ZIP Code, it showed that here in northeast Kansas our electricity comes predominantly from coal — which unfortunately is associated with a lot of greenhouse gas pollution. And you can see from the graph that our fuel mix does in fact produce more carbon dioxide pollution than the national average.

So if you’d like to find out where your electricity comes from, just try the link and find out. And if you haven’t already, now is a great time to learn more about green power options from your utility, or other renewable energy options for your home.

It’s easy to get excited about the potential of solar and wind power. For one thing, generating electricity from the sun and wind is a great alternative to burning fossil fuels because it does not produce carbon dioxide emissions or other air pollutants. But did you know these renewable technologies can help fight poverty, too?

That’s because solar panels and wind turbines can bring power to parts of the world where people don’t have electricity. In fact, an estimated 1.6 billion people — a quarter of the world’s population — do not have electricity at home, according to the Energy for Development report from REN21 (the Renewable Energy Policy Network for the 21^st Century). Installing small-scale solar panels and wind turbines can be an especially effective way to bring electricity to these areas, because it doesn’t require the enormous investment of, say, building a coal-fired electric plant and transmission lines.

The REN21 report mentioned above was published by the Worldwatch Institute, and it’s full of good information on renewable energy and poverty. You also can find more information on this subject on the Worldwatch Web site. For example, here’s one interesting article about a successful pilot project in rural India. The project brought solar power to 100,000 people who previously did not have reliable electricity. By providing electricity for lighting it reduced local reliance on kerosene, a fuel that was often unavailable or unaffordable — and that can cause serious problems with indoor air pollution.

Do you know of other projects where renewable energy is being used to alleviate poverty? You can share your thoughts by posting them in the comments field below.

Climate change getting you down? If you've ever wondered if humanity can really do anything about greenhouse gas emissions, watching David Letterman's recent rant about climate change may help you get it all out of your system. (You can find it here on The Huffington Post. The quick summary: We are dead meat.)

But this week I’ve been feeling more optimistic, and for good reason. On Tuesday and Wednesday I attended the Kansas State Energy Conference to learn more about what’s happening locally and nationally on different energy issues. As part of that, I was lucky enough to get to hear the keynote address from one of the leading experts on climate science, Dr. James Hansen.

Don’t get me wrong, no one is likely to walk away from a lecture on climate change with a rosy view of the Earth’s future. It certainly wasn’t all good news. But at the same time, Hansen wasn’t saying that we’re dead meat or that it’s already too late. Instead, his message was that we still have time to act.

However, it’s a narrow window. We need to take serious action immediately, and it sounds like we’re talking about some pretty major steps — such as figuring out how to get off of coal completely unless we can figure out how to capture and store the carbon. There’s a great article from Hansen here on the Worldwatch Institute Web site with much more information on his views on climate.

Another bright spot: It was exciting to be at the conference and see how much is already happening in the world of wind power. There are a lot of new wind turbines being installed here on the Great Plains and in other windy spots around the world. Let’s keep them coming.

Photo by RUSTY DODSON/ISTOCKPHOTO

Wouldn’t it be nice if all the energy we used could come from local, renewable resources? Here’s a great article from the San Francisco Chronicle about people who are trying to make that idea a reality. (You can also read the article here on Common Dreams.)

It explains that just as a “locavore” is someone who eats locally grown food, a “locavolt” is someone who seeks energy created from local, renewable resources. One “locavolt” idea mentioned in this article is a concept Mother Earth News readers may already be familiar with, community supported wind.

If this gets you started thinking about producing energy locally, here are a few other resources you might want to check out.

* Do you live in a good location for producing solar or wind power? Here’s an article with more information on evaluating your home’s renewable energy potential.

 * To learn more about community supported wind power, a great resource is the non-profit organization Windustry and their Community Wind Toolbox.

 * The U.S. Energy Information Administration (EIA) has state and country energy profiles with good background information on energy issues in different areas. For example, here’s the profile for my home state of Kansas. Not surprisingly, it shows that we burn a lot of coal from Wyoming, but don’t yet have a lot of wind turbines.

What are some of the energy issues where you live? You can share your thoughts by posting a comment below.

Wind turbines come in all sizes, but if you’re trying to understand exactly how big a wind turbine is some of the terms are unfamiliar. What’s a kilowatt exactly? How is that different from a megawatt?

There’s a handy cheat sheet here that explains all the measurements, but I find them a little hard to visualize. Fortunately, there are a lot of great photos out there on the Web! Below are a few wind turbine photos as a frame of reference. You can find many more wind turbine photos online by visiting the Web site of the National Renewable Energy Lab.

Small Wind Turbines

The smallest home wind systems are equal to about a kilowatt. For example, the wind turbine pictured in this cornfield is a 1 kilowatt wind turbine.

Another common size of small wind turbine is a 10 kilowatt turbine, such as the one pictured by this house.

For a better sense of what sizes wind turbines come in, check out this page from the American Wind Energy Association. It has a list of manufacturers of small wind turbines (defined here as anything 100 kilowatts or less), and the models they produce, with links to more information.

Big Wind Turbines

On the other hand, some of the commercial scale wind turbines are closer to a megawatt (1,000 kilowatts.) The wind turbines pictures along this road are 1.5 megawatt wind turbines.

If you want to get a better sense of what megawatts means, check out this handy map from AWEA that shows commercial-scale wind projects in the United States. Click on the links to different states and you can find out exactly where new wind projects are being built and how many megawatts they are.

 Photos courtesy DOE/NREL

So how big is that wind turbine exactly?

When you’re talking about wind, it helps to get familiar with the terms kilowatts and megawatts. There’s a handy cheat sheet here that explains all the measurements, but I find them a little hard to visualize, so I thought I’d post a few pictures as a frame of reference.

What does a 1 kilowatt turbine look like? Something like the photo above of a wind turbine in the cornfield. For more perspective on the various sizes of small wind turbines, check out this page from the American Wind Energy Association with more information about the various models of small-scale turbines and their relative sizes.

On the other hand, some of the commercial scale wind turbines are closer to a megawatt. The large wind turbines pictured next to the road are 1.5 megawatt wind turbines. (1 megawatt is equal to 1,000 kilowatts.)

For a better sense of what a megawatt is, check out this handy map from AWEA that shows the number of installed megawatts by states. Click on the links to different states and you can find out exactly where new wind projects are being built and how big they are.

Photos Courtesy DOE/NREL

Wouldn’t it be great if more of our electricity came from wind and solar power? There are a lot of good reasons the United States should start generating more electricity from renewable sources. But what will it take to make that happen?

One thing we are likely to need is an upgraded, expanded electric grid with more transmission lines extending to the sunniest and windiest parts of the country. Today, there’s a great article in the New York Times that does a good job of explaining the connections between transmission upgrades and developing renewable energy.

You can find another good discussion of the need for grid improvements here in this recent article from Renewable Energy World. It was originally published by the American Wind Energy Association, and includes many details about how upgrades to the grid could help speed up the development of wind energy.

 It’s also worth mentioning that some individual states are already leading the way with transmission upgrades — notably Texas.

Do you think the United States needs to upgrade its electrical grid? Tell us your thoughts by leaving a comment below.

Photo by Tom Wald/Istockphoto

This week, there’s a nice article from Worldwatch with statistics on exactly how fast renewable energy is growing in the United States. The good news is, it’s growing rapidly — especially electricity from wind and geothermal.

But it made me wonder, exactly how much of our electricity already comes from renewable sources? Well, according to this fact sheet from the Energy Information Administration (EIA), it’s about 8.5 percent, and almost all of that is from hydropower — 6 percent.

Where are we going? One EIA projection says that we could be at 12.6 percent renewable electricity by 2030. Not very inspiring, is it? However, the U.S. Department of Energy also projects that we could produce 20 percent of our electricity from wind by 2030 if we address several challenges, including the need for additional transmission lines.

On the other hand, Al Gore recently challenged the country to set the audacious goal of getting 100 percent of our electricity from renewables within 10 years, so by 2018. It’s easy to see why he compared it to the challenge of putting a man on the moon: That would be a huge leap forward from where we are now. But it might be just the push we need to make the transition to renewable energy.

What about the presidential candidates? On his campaign Web site, Barack Obama specifically calls for 10 percent of our electricity to come from renewable sources by 2012, and 25 percent by 2025. (On his Web site, John McCain doesn’t suggest a specific goal for renewable electricity, but does say he favors support for renewables, including through tax credits.)

What kind of goals for renewable energy do you think the United States should aim for? Share your comments below.

Which countries have installed the most wind power? It used to be Germany, followed by Spain. But the United States is now in the lead, according to estimates from the American Wind Energy Association. You can read more about it here in the Financial Times, or here, on Live Science.

 Looking for more statistics on wind energy around the world? A good source for this kind of information is the Global Wind Energy Council. Here’s their 2007 Global Wind Report (pdf).

Texas is already the U.S. leader in wind power with about 5,300 megawatts of installed wind capacity, but that lead is likely to get even bigger thanks to a new multi-billion dollar transmission upgrade that was just approved by Texas regulators.

Transmission capacity is a frequent stumbling block for windy parts of the world that want to put up more wind turbines. That’s because utility-scale wind projects require high voltage lines to carry the electricity where it’s needed. The transmission upgrades in Texas will make it much easier to build new wind power projects because they will help connect windy West Texas with the state’s largest cities.

Read More:

Texas Approves a $4.93 Billion Wind-Power Project, New York Times, New York Times

Texas to Spend $4.93 Billion on Transmission Lines for Wind Power, EERE

Can you afford solar-electric panels, or a backyard wind turbine? For a growing number of people, the answer is yes.

But how you answer that question depends a lot on your state's net metering laws, because this one policy makes it much easier to pay for home solar or wind-electric systems.

That’s because net metering policies allow you to sell any extra electricity you produce back to the utility at the retail rate. It’s a simplified billing process where when you’re drawing electricity from the grid, your electric meter spins forward; when you’re producing electricity that you’re not using, your meter spins backward.

If you don’t have net metering, the utility can charge you more for the electricity you buy than you get for the electricity you produce. For a grid-connected wind or solar system, that makes a huge difference in how quickly the system pays for itself in reduced electric bills.

Currently, most U.S. states have net metering laws, although they don't all make it equally easy to connect to the grid. For more specifics on state policies, check out this list from the Database of State Incentives for Renewables and Efficiency (DSIRE). Only eight states don’t have net metering laws: Alaska, South Dakota, Nebraska, Kansas, Tennessee, Mississippi, Alabama and South Carolina.

Fortunately, more states are passing net metering laws all the time. So if you want net metering and don’t have it, let your state legislators know!

Photo by Michael Braun/Istockphoto

Ever wondered what kind of places use wind power? Check out the links below for a few examples. These 25 very different places all get some or all of their energy from wind power.

1. Hersheypark, Hershey, Penn.
2. Sacred Heart Monastery, Richardton, N.D.
3. Marina Nature Center, Berkeley, Calif.
4. Mackie's Ice Cream Shop, Scotland
5. Ski Resort, Vail, Colo.
6. Betty's Hope Sugar Mill and Morgan Lewis Sugar Mill, Caribbean
7. Maple Honda Dealership, Canada
8. Pioneer Millworks, Farmington, N.Y.
9. Pizza Fusion, Florida
10. Great Western Hospital, Swindon, Great Britain
11. Mohawk Fine Papers, Inc., Cohoes, N.Y.
12. New Belgium Brewery, Ft. Collins, Colo.
    
13. City of Varese, Italy
14. Audubon New York
15. Highball Distillery, Portland, Ore.
16. Only Natural Pet Store, Boulder, Colo.
17. Calgary Light Rail, Canada
18. Rosebud Sioux Indian Reservation, South Dakota
19. Southface Energy Institute, Atlanta, Ga.
20. City of Houston
21. Solrose Studios, Santa Barbara, Calif.
22. Green House Data, Cheyenne, Wyo.
23. Strosniders Hardware Stores, Maryland
24. Earthology Records, Hinckley, Minn.
25. John Masters Organics, New York

 Do you know of other wind-powered places? Share them in the comments section below.

Wind energy is the nation's fastest-growing form of renewable energy. Despite sometimes heated debates (even here at Mother Earth News) about the aesthetics of wind farms and the reliability of wind power, according to Business Week, in the past five years, output from wind farms has grown tenfold. Today, wind farms meet 1 percent of U.S. energy needs. Advocates of wind energy say wind could someday supply 10 percent of all U.S. electricity, as it does already in countries like Spain.

One of the largest complaints about wind (and solar) energy is a lack of constant supply. If the wind stops blowing, people depending on the breeze are in trouble — or are they? A group of Midwest utilities outside of Dallas Center, Iowa, is currently working on technology that could solve the problem of storing wind energy by tucking it away underground. The system works by funneling compressed air into a deep well. Thousands of feet below the surface of the Earth, the compressor pumps air into layers of sandstone. The porous sandstone acts essentially like a big balloon, and when wind supply is low, the flow is reversed and the chamber empties, bringing a whoosh of air back up the pipe and into a natural-gas-fired turbine.

This isn't a distant pipe dream, either; the project began in 2003 and is expected to go online in 2011. There are already two compressed-air storage facilities operating in the world (one on Germany and one in Alabama), but they are not driven by wind turbines.