Residential Wind Turbines

[Floydian]

I started doing solar installs a few months ago. PV and hot water. Most of the PV systems are pole mounted and grid tied. Some roof mounts but you cant adjust the panels a few times through the year and they stay warmer which equals less efficiency. The hot water systems I've done are from Thermo Dynamics. They are complete systems and pretty easy to install. They have a 20 watt panel that powers a DC circulator so they work when the grid doesn't. In most areas you can produce between 50 to 70% of domestic hot water needs. My boss wont touch wind unless its a perfect site and there are not many according to him.

 

[SPIKER]

if you go to this forestry forum the 2nd page here has a very long post regarding wind there are also solar and gas/ethanol posts going on now which are all good reading with lots of links posted by people who are off grid in bad locations ect. I was supprized at how affordable the new designs are becoming and how little wind is needed...

http://www.forestryforum.com/board/index.php/board,3.0.html

mark

 

[Eagleview]

A problem with feeding power back into the grid which can become life threatening is that when a lines man has been assured that the grid power is off by the supplier . He may well get a "supprise" when he touches a wire just as someones auto switch on their system senses the batteries are charged and directs current to the grid .

 

[Lasgambler]

Unless you live in an open place where you constantly curse the wind and your wife has the washing blown off the line , forget about wind power . As stated , put some Photovolactic solar panels on the shed roof and sit back . Even on a cloudy day my panels are putting charge into the batteries . Turbines are noisy , unsightly , are often stationary and have parts that wear out , it's a nice thought to harness the wind but is not a trustworthy supply of power .

Iron Horse pretty well sums it up!

I have been building homes off grid for about 5 years now and know the Turbines are a waist of money. However I live in an area with over 300 days of sunshine per year.

 

[cdaledave89]

Forget it. A local company called Vox Energy Solutions had a booth at the Home Show here in March and I talked to them about the turbine they had on display. Well, after trying to get in touch with them for four months I finally talked to someone who was interested in helping me. I sent a copy of my electric bill & usage. After a few weeks they told me that 2 options would work for me: a larger turbine that would handle 80% of my yearly electric usage at an installed cost of $86,000 and a smaller one (the Skystream 3.7) that would generate about 20% of my electricity for an installed cost of $16,000. I was told that the payback would be 28 years for the large turbine and 22 years for the small turbine. When I asked for details of how the payback was calculated I soon found that: 1. Their calculation sheet was completely erroneous (math errors). 2. They assumed that the pending de-regulation of electricity utilities in PA in 2010 would result in price increases of 10% per year for the next 30 years. (possible, but highly unlikely) 3. They did not take into account that the electric company will probably charge an additional monthly fee to be enrolled in net metering (feeding back into the grid). 4. They based their generation calculation on the median rating of the turbine - not the anticipated wind conditions at my location - nor did they offer to conduct monitoring of actual wind speeds.

I did my own (reasonable) calculations and determined that the payback for the smaller turbine would be near 60 years and the payback for the larger one would be well over 100 years. This didn't even take into account the investment income that I would lose if I just sat on the money in a simple savings account. My monthly electric bill is only $100, so there is no way that this is financially smart. I can't see the economics working for anybody except those choosing to be off-grid.

 

[QRTRHRS]

A problem with feeding power back into the grid which can become life threatening is that when a lines man has been assured that the grid power is off by the supplier . He may well get a "supprise" when he touches a wire just as someones auto switch on their system senses the batteries are charged and directs current to the grid .

The systems that I was involved with nearly 30 years ago sensed line voltage or they would not generate. Though nothing is certain with electricity and electronics. I wish I could remember more about backfeeding. PP&L was very concerned about safety and had their engineers on the jobsite overseeing everything we did.

Do we have any linemen on the forum? I would think the threat from backfeeding gas generators was everpresent already?

 

[RonMar]

A problem with feeding power back into the grid which can become life threatening is that when a lines man has been assured that the grid power is off by the supplier . He may well get a "supprise" when he touches a wire just as someones auto switch on their system senses the batteries are charged and directs current to the grid .

All the grid tied systems I have looked at do not use batteries. There is no point in batteries if you feed power back to the grid, the grid becomes your battery. All these approved systems disconnect at the loss of commercial power. IE, even if you have sun, if you don't have commercial power on the incomming lines, the inverter will not run. they have to do this to get installation approval.

From the more practical standpoint, in the event that the anti-islanding circuitry should fail. Unless the break in commercial power is on the line feeding your house from the power pole on the street, your little inverter is quickly going to fall on it's face(shutdown, blow fuse, or fail)when it attempts to power your neighborhood...

And having watched quite a few linemen work, no one in his right mind just goes up and touches a line. It gets tested, then grounded, then worked on, then ungrounded, then power is re-applied. The testing, grounding and ungrounding are done with insulated poles.

 

[Eagleview]

All the grid tied systems I have looked at do not use batteries. There is no point in batteries if you feed power back to the grid, the grid becomes your battery. All these approved systems disconnect at the loss of commercial power. IE, even if you have sun, if you don't have commercial power on the incomming lines, the inverter will not run. they have to do this to get installation approval.
.

So what you are saying is that at night when you are home from work and your consumption is greatest , you are using power from the grid ? And when the mains power supply is out for whatever reason , so is your stand alone power ? What is the point of having Solar Power if you have no storage ? And in regards to no linesmen ever touching live wires , many die each year from doing just that , we lost one last month . Also many times we do'nt turn off the grid power , our linesmen work on the live lines using insulated cherry picker booms etc , they also reach out of Helicopters and work on live high tension power lines but when they are doing so they know it's live and take special precautions as apposed to when someone with an illegal power hookup starts his generator etc and charges the line from the other end that is thought to be off line .

 

[RonMar]

So what you are saying is that at night when you are home from work and your consumption is greatest , you are using power from the grid ? And when the mains power supply is out for whatever reason , so is your stand alone power ? What is the point of having Solar Power if you have no storage ?.

That is correct. What is the point? You are being green. All day while you are at work and your house load is minimal, your solar system is happly pumping green killowatt hours into the grid and spinning your meter backwards(actually spins a second meter in all the systems I have seen). When the sun goes down, you start drawing power from the grid spinning your main meter forward. If everything is sized correctly and your consumption isn't too great, you should have no bill or even receive a check from the utility for the KW hours you have provided. Or you will build credit in the summer and use that credit in the winter. It is this savings in electric bill that eventually pays for the system. This isn't backup power, it is an investment that will eventually pay for itself while it helps the environment. Batteries are not economically feasable if you have comercial power available. You want backup pwer, get a generator

These days batteries are half the cost of a PV system, and where the PV panels may last 20 years, the batteries will not. They also require attention to detail and maintenance. And the real kicker is that watts are watts regardless of the source. To power large loads like A/C or electric ranges or cloths dryers would require a prohibitively large inverter and battery bank that is under used most of the time. The only people who use batteries are those that have no other option, IE: the battery life cycle costs and alternate fuels are less expensive than getting commercial power to the site. And again, since the size necessary for an all electric house is very spendy, most will shift the larger loads to propane or use a generator, or do without.

And in regards to no linesmen ever touching live wires , many die each year from doing just that , we lost one last month . Also many times we do'nt turn off the grid power , our linesmen work on the live lines using insulated cherry picker booms etc , they also reach out of Helicopters and work on live high tension power lines but when they are doing so they know it's live and take special precautions as apposed to when someone with an illegal power hookup starts his generator etc and charges the line from the other end that is thought to be off line .

That is a shame, but more than likley is that either proper procedures were not followed, or some physical accident such as a pole or structure failing brought them into contact with live lines. The rule is that ALL lines are treated as if they are hot. When the proper steps are not followed, that is when people get hurt... I have never looked, but I don't think I have ever seen a case where someone was hurt from backfed power. I am sure it has probably happened, but Again, it is not very likley. Watts are watts, regardless of the source. A power source that would power your home would shred itself in short order if it tried to power your neighborhood...

 

[Eagleview]

A power source that would power your home would shred itself in short order if it tried to power your neighborhood...

I'm still a little confused , if what you say above is correct . How then is a usefull amount of power fed back into the grid from the solar panels on a residential house without doing damage to itself ? And that same power not leathal to linesmen ?