admin answers:

I do not think there is that many types of wind turbines because wind turbine’s solo purpose is to make eletricity and they don not really bulid them in the suburbs because it may be noise and it take a lot of space and also ot needs a lot of wind so only a limited area will be able to set up wind turbines.

admin answers:

The turbine has to be 30 feet above surrounding buildings and trees. It has to be two tower heights away from any building. If it falls in any direction, it must not cross a property line. You pretty much need to have an acreage to have a wind turbine.

admin answers:

Eath4Energy is a scam. Please see my review at http://www.nlcpr.com/Deceptions6.php

If your motivation is to reduce your energy bills, then you should first look at conservation projects. These are things like using low flow shower heads, replacing old appliances and adding more insulation.

If your motivation is to generate some energy for learning purposes or as a matter of principle, then consider the following:

Building a wind generator yourself is not a simple project. If you can build an utility trailer for your truck (welding, metal fabrication) then you could certainly tackle the job. There is a great book available from www.otherpower.com called Homebrew Wind Power plus you can order any parts and assemblies that are beyond your abilities to fabricate. Cost of turbine is about $2000 and you need a tower as well. There are cheap units at some hardware stores but they are garbage compared to to the unit designed by www.otherpower.com

A more realistic project would be to get a commercial solar panel (making your own from broken cells on eBay is not worth it), inverter, charge controller and battery and using it to power some things in your house. For about $1000 you could have something to power a small computer. A complete system to power your home is more in the $30,000 range.

There are, unfortunately, no cheap ways to make your own power as Earth4Energy is promoting other than perhaps getting lucky in an eBay auction or purchasing a solar system from a bankruptcy sale.

Do your conservation measures first. Then read Homebrew Wind Power, read the solar links at http://www.nlcpr.com/Links1.php and then decide what type of project you are up for. By then, you will know exactly what you want to do.

admin answers:

Look at the Prairie Turbines site again. The price of the micro-controller including the hall device is $255. The $45 book provides a complete list of material and instructions to build everything else.

The micro-controller monitors the speed sensor and provides control signals to two solid-state relays. One relay connects the motor to the grid when the speed reaches the motor’s 1800 RPM synchronous speed and disconnects the motor if the speed drops below 1800 RPM. The other relay is energized to release the brake when the controller is energized and de-energized by the controller when the motor speed exceeds the maximum safe operating speed. If this occurs, the controller apparently must be manually reset.

I did not find the maximum safe operating speed stated on the web site. If the full load speed of the motor is 1750 RPM, the full load slip is 1800 minus 1750 or 50 RPM. The speed at which the motor would generate full load current and present full load torque to the turbine is 1800 RPM plus the full load slip or 1850 RPM. With the design described, a three-phase motor is connected to a single phase source with capacitors connected between the source and the third motor phase. That is likely to increase the motor slip somewhat.

I am not sure what happens if the motor is driven above the speed at which it generates full load current. A three-phase motor operating as an induction generator connected to a three-phase supply has a torque vs. Speed curve that is something like the mirror image of the motoring torque vs. Speed curve. The curve is likely different with the single-phase connection used in this case. I don’t know what the speed vs. Current curve looks like in either case, but I will see if I can find it. I am also curious to know if the Alan Plunkett listed on the web site as an author is the Alan Plunkett that is well known author of technical papers on inverter and variable frequency drive subjects.

Added information:
I found information indicating that, for a 3-phase motor connected to a 3-phase supply, the speed vs. Current curve for induction generator operation is like a mirror image of the speed vs. Current curve for motor operation. That would mean that the maximum speed would need to be limited to the synchronous speed plus the full-load slip. The web site indicates that the full-load speed for the motor that they used is 1725 RPM for 3-phase operation. That would make the maximum speed 1875 RPM plus the additional slip due to the single phase with capacitor arrangement.

admin answers:

Smoke is a problem because most smoke will also contain carbon monoxide, and that’s not the kind of stuff you want your “exhibit” producing at a science fair.

I have absolutely no idea if it would work…but…Halloween is over and many retailers will prbably be having clearance sales on their Halloween items. I know that those “fog machines” produce their own cloudy “stuff”. I’d suggest you look into a buying a discounted fog machine, now that the sales are on.

You can also make your own fog machine if you want.

admin answers:

Actually, check out some of the links on http://www.builditsolar.com

If you are going to do much of the work yourself, you will be sadly disappointed by what is available in print:

Homepower magazine http://www.homepower.com for example, it most often reads like a sales brochure, because “hands on” to a number of people usually means buying most of the system ready made in a kit. Hands on for me is breaking out the soldering iron and doing point to point wiring on components to construct the regulators (often called charge controlelrs.) Too much chaff for a hands on person to find useful. Some of the ads are useful.

Nuts and Volts http://www.nutsvolts.com/ is a bit better, but their topical coverage is far ranging so you do not always get as much as you would like. Spendy, might be better to sheck it out at the bookstores and buy it off the newstand when a decent article appears.

Mother Earth news http://www.motherearthnews.com is pretty good, but the best bang for the buck there is to buy their archives on CD rom, which is 3 disks, broke down by decade. There is a fair amount of substance, sometimes you encounter an article that sought to convert one item over to another, only it would have been much less work and cost for them to have started out from ground level and construct (with used parts) the same thing, which they sought to construct in the first place, a solar charged electric tractor is one specific item I have come to mind as one the author of the article could have done better. You might find the book they published “The Mother Earth News Handbook of Homemade Power,” which is not real good for specifics in some areas, but is good for some ideas if you are good at working from thumbnail sketches, you can fill in the blanks where there are gaps in detail. The book was written more as a “primer” than a complete compillation.

For your wind systems, there is a lot to be found at http://www.lindsaybks.com Hugh Piggott has written a few good books on the home construction of windmills. The LeJay Manual is a good reprint that has a lot of good info for home constructing- down to the wooden propeller profiles. As well as the book “Generator Secrets.”

One of the good sources for materials and tools supplies and systems is Northern Tool http://www.northerntool.com

One thing on propeller materials- never us ABS and never use PVC. As tempting as those can be they break. When they break, the blades will go for a great distance in modest winds. They can kill too.

admin answers:

The current establishment cost of a coal fired power station is about $2000 per kilowatt of power produced. Over a 50 year life; this is quite low compared with establishment costs for wind and solar power generation, and a lot (hundreds) of wind generators are needed to produce the same power output of a large coal powered generator. This is why it is proving difficult to replace coal for large scale power generation.

Here’s a wiki ref:
http://en.wikipedia.org/wiki/Fossil_fuel_power_station

admin answers:

Energy conservation can show how efficient/cost effective a wind power generator can be.

admin answers:

As can be seen from the power curves in the first link, there is nothing till about 12km/h wind, then only a small fraction of the maximum power which is reached at around 28km/h. It is important to undertake a proper survey, as wind shear can have a large influence. The Vestas site has advice about planning, but not much detail. Send them an email.

In this kind of situation, with no grid to fall back on, it is usual to have diesel generators running to smooth the load. These are special “low load” types (see the 6th link below). They run on no load when the wind is there, synchronised with the wind generators.

I should warn you that it is easy to convince yourself that a wind system is ok when it isn’t, because you want it to be true. There are all sorts of considerations. It may make sense to have oversized turbines so you still get enough power despite bad wind. What happens when no-one is using power? One or two big ones or lots of smaller ones? You need the turbine manufacturer and/or experienced consultants to help make these decisions with a proper site appraisal. If the trees are all horizontal that is a good start. It should definitely be what most people would think is a windy place, and with steady winds. Solar panels are easier to engineer, perhaps lower risk, but it does depend on where you are too. No clouds in that case. It is not uncommon to have them together, with the low load diesels.

You probably already know the peak power demands from existing power supplies. You should try to factor in for 25 years growth of island power usage too. The figure varies, especially because or airconditioning/heating situation. One could say a typical is 4kWh per house per day. You have to consider community buildings too. This figure takes no account of peak demand anyway. It tells you how much fuel you need for diesel generators.

Vestas is a Danish pioneer in larger wind systems, with some innovative features.
The first link shows power versus wind speed.
The second link also has these for the latest models, look for the brochures. It also gives advice about
The third link has a list of other manufacturers.
The 4th and 5th links have pictures of wind farms with some details that could be helpful for contacts.
The sixth link is about low load diesels.

admin answers:

Climbing 200 feet is important. Once a year someone has to climb down and hand inspect each blade. Being comfortable working on machinery at 200 feet is required. You don’t climb much in nasty weather, but you will climb to the nacelles in winter.

Most windmills use a induction generator with a back to back inverter. The generator generates power at whatever frequency, and the inverter converts it to 60hz. Being able to trouble shoot this type of equipment is a plus.