Billy's Wind-Talk Blog

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Average wind speed for 59 years    

Note: Most wind generators start generating at 9mph, and are at full load at 16 mph

April 20, 2009   Buying a system

The wind system at Santa Maria, Texas:  This system consists of 2-2kw wind turbines.  120 volt 3 phase generators, 120 volt dc battery pack and 3- 2kw sine wave inverters.  The inverters are wired into the house on isolated circuits balancing the load across the inverters.  For the past 4 months the system has been very stable, the battery charge holds at 120 volts after a 3 day test with the wind generators on brake.  The control system will keeps the battery pack in full load wind at 140 volt dc.  Use of multiple generators  allows for maintenance of the system without power interruptions. 

With the Federal Government incentives you save 30% of the total cost of your installation either stand alone or grid tie.

What is the difference between Stand-Alone and Grid-Tie.

A stand-alone system uses batteries to store the power you generate.  When the wind is not blowing the batteries supply you with the power.  You will need enough battery to keep your system powered until the wind speed returns, 1 week or 7 day supply in a wind zone 2-3 should be enough for the average system.  You are not dependent on commercial power.

Grid-Tie system: In a grid-tie system you use the commercial power company as a backup supply.  When the wind is blowing you use the wind power for your system.  When the wind is not blowing you buy the power from the commercial power vendor.  If the commercial power vendor's power is off for any reason your power is also off. 

Most states have a net metering law that allows you to sell your excess power back to the grid.  You will need to check with your power company for the specifications for hooking your system to their grid.

Myths:

1. Wind Turbines kill birds.

I have been using small wind turbine generators for the past 8 years, never have I seen a bird even fly near one when it is moving.  They do sit on them when idle.

2. Wind Turbines are noisy.

On a properly maintained system the noise sounds like wind blowing through the trees.  The decibel level is below the song birds.  The noise level will depend also on the size and number of the propellers, three blade propellers of 6 foot (12foor diameter) and up turn at 400-600 rpm and make less noise than a 6 blade 36 at inches (6 foot diameter).  The blades as shown in our video on www.hightecenergy.com  are quite.

3. The power is not reliable:

As in any system reliability comes with a good design.  While a poor design may not be reliable a good design is very reliable and stable.  With the proper blade design for your wind zone, tower height, generator size, and battery pack a wind system will give you years of reliable service.

4. Maintenance is high and costly:

A good wind turbine will have sealed bearing and require a shot of grease once every 2 years.  The batteries on a stand alone system will require water every 30 days, on a large system it takes about 5 gallons of water.  You will need to mow the grass under and around the towers.

When you purchase a wind system it needs to be designed to meet your power needs, if stand alone or grid-tie.  Remember a poorly designed system will perform bad, while a will designed system will meet and exceed your needs.

April 21,2009   Pay back time

When I talk to potential customers they always ask. "How long is it going to take me to pay for the equipment?"  This is a very good question.  When you decide to spend 15 to 20 thousand dollars on equipment that will generate enough power for an average  style of living it is a big step.  First lets look at your electric bill.  What have you purchased?  Electric power, a consumable product.  This product has no resale value, lets say your electric bill costs $600.00 per month in a years time you will spend on the average $7,200.00 dollars.  In ten years that's $72,000.00 dollars.  Now you are deciding if it is worth purchasing an off grid system that will eliminate your electric bill.  Lets look at what bills will replace your electric cost.  First you have the initial purchase and installation of the new power equipment.  For example the cost is $20,000.00 dollars, and you finance it for 5 years. Lets say a payment of $400.00 per month for 60 months.  Your monthly maintenance for checking the system and batteries  $60.00 per month, $720.00 per year, 10 years 7,200.00. But lets just say $9,000.00.  Now lets move out to 10 years, because that is what we did with the electric bill.  Equipment cost with interest $24,000.00, Maintenance fees $ 9,000.00, and lets add another $5,000.00 just to cover any equipment replacement.  That comes to $38,000.00 a savings of $34,000.00 and you still have the resale value of the equipment.  Lets say you can resell your 10 year old equipment for $5,000.00.  That means that over a 10 year period you have saved enough money to purchase a new system and that new system that now costs $30,000.00.  Is it worth it? I would think so.  When the savings from the initial system not only paid for itself but also paid for your new one, and you still have $9,000.00 to spare.

That does not include the 30% TAX CREDIT from the Federal Government that is in place today. 

April 22, 2009   The Grid

There sure are a lot of !nay-Sayers!  The utility companies have a problem with people who wish to generate their own power.  This is because as more and more do so the utility company load drops.  Their generators have a min-load and when it gets below that the generator must be turned off.  It takes 24- 48 hours to start a unit back up.  They do not want anyone producing their own power!  Net metering laws were set up so that people who are generating power from wind or solar can replace the energy they consume with that, that they generate.  Now the utility company says that you have to have 2 meters one incoming and one outgoing.  This so that they can charge you the retail price and buy back the power you generate at a few pennies.  Lets say you use 20kwh in one day, and you generate 20kwh, with one meter the total usage is zero "0".  Now with 2 meters, incoming meter 20kwh x .20=$ 4.00 , outgoing meter 20kwh x .05= $ 1.00.  Well maybe theirs cost more to produce than yours does,  if so then when they resell your product for .20 per KWH.  That is why now 2 meters going and coming.   We are not in the business of selling electric power, but in the business of reducing your consumption of purchased electric power.  Just like those who use backup generators for power failures,  these generators when started are not connected to the grid, this is for the safety of those who are working to restore the power.  A drop out relay drops out the grid and starts the generator.  Lets do that backwards;  your wind or solar system becomes your primary power source, when power is lost a drop-out relay turns off the wind or solar system and connects the grid.  You then pay for the power consumed until your system in functional.  You now pay a minimal amount for the grid service.  If the grid becomes your secondary power source.

In our demo home, we elected not to use the grid as a secondary power source, but to install a backup generator that will recharge the battery pack.  It is a manual start system, I used 1944 120vdc Kolar gas driven generator with a crank start.  I do not expect to have to use it much or at all.

Remember that producing the correct amount and voltage is more that putting a propeller and generator on top of a pole.

April 24, 2009  Vertical and Horizontal wind generators.

Lets look at vertical and horizontal generators.  Vertical turbines are mounted in such a way that the blade rotates in a vertical position. The horizontal turbine blades rotate on the horizontal position.  There is a difference in how the torque is dispersed by the pole. As load is added to the horizontal turbine the torque twists the pole.  Now start loading and unloading the generator, the back and forth twisting motion heats the metal and causes metal fatigue. The torque on the poles never changes even if the wind changes direction.  On the horizontal the torque on the generator is on the bolts that hold the unit on top of the pole.  The pole does not twist, on a guy-wire system the wires absorb the load torque.  This torque changes as the wind changes.  Not to say that vertical units are bad or that they cannot be engineered to last, but they are not without their own set of problems.

Loose guy-wires on a horizontal system cause load torque problems on the poles.  The poles will shake. As wind turbines and generators increase in size the load torque on both horizontal and vertical systems increases adding stresses to the poles and guy-wires.

Towers and pole installation are important to the life of an installation.

The stand-alone system:  An electric generating system that uses wind as fuel and charges a battery system which in turn is converted to ac voltage through an inverter.

With the problems arising from the utility companies for the use of grid-tie systems, the stand-alone type has less problems.  In areas where the grid is available, for those who are faint of heart you can install a transfer switch, if the stand-alone system fails then the transfer switch takes it off-line and brings on the grid.  I spent many years in the air conditioning contracting business, when we installed a central air system in a home that had window units the owner would tell us that he wanted to leave the window units installed, even though they looked bad.  This was so that when the central unit did not work he had a backup.  The same applies to the stand-alone systems. Are they reliable?  If they are designed correctly the answer is yes. 

April 25,2009    How much power

What most worry about is not having enough power.  Wind power is different from other types of power that run generators.  With steam power, or petroleum.  These energy sources can be controlled, wind on the other hand cannot.  The amount of power produced is relative to the speed of the wind.  The controller on a wind generator simply adds load to the generator to keep the generator with its operating range.  If you look at a 2kw system that will generate 2kw at 16 mph wind that is 20 amps at 120 volts.  As the wind speed increases the controller add load to the generator up to 2kw or 20 amps at 120 volts ac.  In a strong wind that is gusting above 35 mph the generator will produce up to 30 amps at 120 volt ac that is 3kw.  This is power produced, if this power does not have the load necessary, or the ability to store the extra power, it results in damage to the wind generator, or a burn out. Keep in mind that on a conventional generator you reduce the amount of input power to match the load on the generator.  On a wind generator there is no way to control the amount of input power, you can do two things.

Most systems are either under or over powered.  The under powered systems are not adequate and will never provide you with enough power.  These are costly and you will never see a savings.  While the over powered system will make enough power, they have a  high rate of equipment failure.  Then all your savings are spent on repairs.  A well designed system will give you years of service.  The new wind turbine and generators are not the same technology as those used during the early 1900's, to supply power for a few light bulbs.  This new generation will when correctly sized supply your home with a dependable supply of electric power. 

April 27,2009

We had very high winds this weekend, gusts to 40 mph.  I braked the low 35 foot turbine and left the 90 foot unit running.  By lowering the reading on the battery voltage I am able to raise the battery voltage to 150vdc.  This will give me an equalizing charge on the battery pack.  This is part of the maintenance by equalizing it removes the sulfide partials from the battery.  Today we are going to have high winds again so the 90 foot unit is on brake and the controller for the 40 foot is set at 140vdc, this will keep the battery floating and at full charge.  After today we will need to check the water levels in the battery.  Large batteries like the ones used by High Tec Energy will use 5 gallons per months.

April 29,2009  Lifestyle off the grid.

It is different, you have a predetermined amount of power on hand, where the grid in theory has an unlimited amount you can purchase.  It is kind of fun to sit on the porch and watch the propellers turn, it makes you think of simpler times.  The lights turn on when you hit the switch, the soft drinks are cold, the ice cream is frozen, the air conditioner keeps the house cool.  About the only difference is, I really cannot think of one.  I know  nobody has to send me a bill!

Mass Storage:

When you read the blogs about wind generation and the grid, the problem being storage.  The storage problem is not as bad as you would think.  There is a system called a pump-storage,  during off peak times when loads are low, generators are motorized and used to pump water from a lower lake to a high lake.  During high load times or peak loads the water is used to operate the hydro generators.   Lets take wind power, when the grid load is low and there is no place to put the wind power, (the wind generator must be taken off line even if the wind is blowing) this power can be used to pump water from a low lake to a high lake.  We do not need to store the electric power as electricity but as the power needed to produce the electric power.  Wind generators on the coast of Texas can motorized generators in the Rockies' to store the  energy.  This will the wind generators to stay on the grid (wind does always blow when the load is high) during off peak times and relieve the fossil fuel units at peak loads.  Who knows with enough storage we might even eliminate the fossil fuel units all together.

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