Wind Turbines

[Pappy]

At this point this is more curiosity than anything else. I have a customer that produces his own power for his house with solar panels. He is connected to Austin power but says that he sells to them more often that he has to use their power.

What would it take to power a shop completely off-grid using a wind turbine? If a system based on this one from Northern Tool would be sufficient, the system would pay for itself in a couple of years. I will have to pay to have a transformer installed to connect the shop to the city grid so that would be about $500 saved initially. I would also be runing power to 2 storage buildings and a finishing room (The current Playpen). One storage building (wood) would be only one circuit for lights and an outlet to plug in a fan occassionaly, the other one (garden pony barn) would have a circuit for lights/ceiling fan and another for plugs. The finishing room would need 3 circuits. (Lights, compressor, power outlets)

http://www.northerntool.com/shop/too...9318_200449318

[LCHIEN]

The problem with wind is that when it blows its producing continuous steady power. But your application, woodworking, takes bursts of high power when the machines operate and uses low power when not running (just lights). You need a way to store power to meet your peak needs, which is usually costly. In order to run your equipment you have to have a generator big enough to handle the maximum or peak load - maybe a air compressor, table saw, DC and Airconditioning plus your base load (lighting, fans, stereo, air cleaner)- 80 Amps. And it won't be available to this level when its calm (no wind).

One solution is the oppoosite of what you asked (for offgrid) and that is to use the grid as a storage medium. By connecting to he grid you will be pushing your continuous power to them when you don't use it and pulling power when you need it. Since the grid is a large number of users, over a short time of a few hours the average tends to stay the same as everyone's peaks and valleys average out and you can operate at with no wind.

By pushing power to the grid most of the time and then pulling power only when you switch machines on, you can handle peaks of 80A to run machines. even when you're pushing maybe 10A or 20A to the grid; when the shop is shut down or idle you will be making money. And your generation equipment can be smaller.

Oh, I see the link its a $2000 1800Watt wind generator unit with storage batteries . The 1800 watts is the output pof the inverter that runs off the batteries and the 600W turbine charges the batteries. In this case you won't have much capacity for running more than a 2 HP peak load, and probably not for very long - your average can't exceed about 600W on windy days, less when its calm.

I'm not really sure of how big a generation facility you have to have to become a co-generator.

[BizCoach]

I agree that using the grid as a storage medium is probably a better deal than buying and maintaining your own. Whether you should go solar or wind (or a combination) depends on where you live, how much wind there is, how much sunlight etc.

Many states and utility companies have a rebate program for alternative systems. If they can reduce demand, they don't have to build new generators so the money that would go into generation can go to you. The feds have a similar deal I think.

See if one of the agencies or utilities that gives a rebate can do a site survey and recommend a technology. Then compare what they say with what the people who are trying to sell you a system say.

Where I live (Connecticut) even with the rebates the solar systems tend to have a payback of 10 years or more. I haven't talked to anyone who has such a small wind turbine as you mentioned. But there is a small scale industrial one nearby put up by the owner of a printing company. I'm guessing they use more power than a wood shop. I think he said it cost $10,000 http://newhavenindependent.org/index...ected/id_22624

You can find info on a couple of smaller test projects funded by the state here
http://ctcleanenergy.com/YourBusines...4/Default.aspx

Some other good links here
http://www.nrel.gov/learning/re_wind.html

[LCHIEN]

This article appeared inthe chron today. some of the electric companies will work with you to install solar panels. you lease them for $110-140 per month and it will prvode about half your electric needs and save you about $50-60 per month buying electricity. Excess electricity can be sold to the power company, up to 500 KWh for 8.5 to 12 cents per KWh, if you don't use any you can sell about $50 worth.

I can see myself telling the neigbors, I lose $70 every month but I'll make it up in the long run...


http://www.chron.com/disp/story.mpl/...y/7544263.html

[Pappy]

Loring, let's see if I'm getting this math right...

$140 to lease the panels/system to save $60 on my electric bill leaves me $80 in the hole.

If I sell back the maximum allowed to the electric company, I make $50.

$80 - $50 = $30 it cost me each month so I can say I am going green.

Somehow this just don't make a lot of sense to my old brain. I can just tell everyone I drive a green vehicle. Dodge Ram that gets 16 mpg, but it's
GREEN!

[Chris_B]

But if you live in CA...

In a normal state, solar makes NO sense economically.

However, here in California the monthly electricity rates are:

• ~$0.30/kWh for ~500-800 kWh/mo
• ~$0.40/kWh for > ~800 kWh/mo

Merely 3.5X the national average...

So if you can afford the capital here in the sunshine, the payback on a modest-sized system (2-3kW) to bring the cost/kW out of the stratosphere is about 7 years.

[BizCoach]

Pappy,
Obviously it doesn't make economic sense most places or everyone would be doing it. There are situations where it does make more sense than others - in places with lots of sun/wind and where the electric rates are high. Plus that $30 a month you're paying goes toward something that when paid off, will put more $ in your pocket. And it does increase the value of the property when you sell. I don't think that was factored in (but on the other side neither was maintenance).

Of course the reason it doesn't make economic sense has a lot to do with politics. We don't charge electric companies for the pollution they cause and we do subsidize oil, gas (and I think coal) and have built an infrastructure that supports older forms of energy better than the newer ones. This is part of the thinking that makes rebates for solar and wind seem fair.

As for economics, I know in Connecticut, when you factor those rebates in then it often does give you about an 8 year payback which is better than you can earn at a bank these days. Connecticut has very high electric rates but not the most sunny place in the land.

I don't mean to say that the politics is good or bad, it just affects what the economics are.

[LCHIEN]

Loring, let's see if I'm getting this math right...

$140 to lease the panels/system to save $60 on my electric bill leaves me $80 in the hole.

If I sell back the maximum allowed to the electric company, I make $50.

$80 - $50 = $30 it cost me each month so I can say I am going green.

Somehow this just don't make a lot of sense to my old brain. I can just tell everyone I drive a green vehicle. Dodge Ram that gets 16 mpg, but it's
GREEN!

actually your math is WRONG.

The generator can only generate about $50 worth of electricity per month - a limit of the solar panel size and the amount of sunshine typically available. You can either use the electricity to save yourself $50 OR you can sell it to the electric company (If you don't use any) for $50, not enough generating capacity for both.

So you are ~$80/mo (~$1000/yr) in the hole to be able to say you are green.

[cabinetman]

actually your math is WRONG.

The generator can only generate about $50 worth of electricity per month - a limit of the solar panel size and the amount of sunshine typically available. You can either use the electricity to save yourself $50 OR you can sell it to the electric company (If you don't use any) for $50, not enough generating capacity for both.

So you are ~$80/mo (~$1000/yr) in the hole to be able to say you are green.

Aren't you taxed for selling the power, like income, or sales tax? And, what would you be...a power retailer, or wholesaler? All of a sudden, you become a utility, or would that be a sub-contractor?.

.

[BizCoach]

Selling power back to the grid is something that's been around for a long time. I've read lots about it and never heard of anyone being taxed. I think because you're helping the utilities (which are regulated monopolies) avoid the cost of building new generating capacity. But I'm not a tax accountant.

Also regarding the calculation. Solar and especially wind generate power at times when you might not be using electricity. The idea that "You can either use the electricity to save yourself $50 OR you can sell it to the electric company" is only true for what you generate when you'd be using it. What you'd generate at other times is a win, I think.

[LCHIEN]

actually, a situation like this you will be most likely a net user (few people use less than $50 average per month electricity, i.e. in the summer when generation will be at a peak but so will A/C useage) so you would be billed for the difference in the power you used and the power you provided, you'd get a smaller bill and no income tax.

If you are a steel mill and have a large coal-fired co-generation plant on premises, you might be a net provider or possibly a net provider some months and a net user other months depending upon your plant utilization. If you are a huge user like that you probably will have a complex long term contract negotiated with the power company that deals with both peak and off peak rates as well as power factor and what percentage of current standard or marginal rates the power company will sell and buy at. Probably the power company will require advance notice as to whether the cogen will be providing power that day so they can have their most expensive-to-operate generators stand down.

I'm sure that months with net income from power cogeneration will be taxable but the cost of fuel and maintenance of the generators is all tax deductable as a business expense.

[Pappy]

My math was intentionally on the side of maximums, so even in the best case senario, I would still loose ~$30!

[wardprobst]

Don,
If you want to go green contract with a electrical company that offers that option. We use Dynowatt, 100% wind power and pay 1 penny per kilowatt for that option above the regular rate.
If you want to get off the grid you will find out that economies of scale make that difficult to do economically at least at this time with the current technology. As you know, we have a southern exposure that would be ideal for solar but I'm not able to justify the cost yet. Hopefully, some day.

DP

[jackellis]

Wind and solar make sense in California and some of the eastern states in very specific circumstances. In Texas, there's almost no way to make it pay given electricity rates, which are pretty reasonable.

If the energy equivalent of natural gas was the same as the price of oil, things would be different. Gas is now around $30/barrel equivalent.

We have a friend who can use either propane or an electric heat pump to stay warm in winter. In summer, they need air conditioning. They installed a 10 kW solar system next to their house and expect to recover the cost in 6 years, but only because electric rates in Northern California are driven by politics rather than economics or common sense. Without the solar panels, they'd be paying $300-400 per month.

[Poobah]

I installed a 6.3kW system when I moved out near Los Angeles. Payback should be about 8 years (3 or 4 years if the current administrations CA and Fed keep f-ing everything up and raising rates like there's no tomorrow). But a large chunk of that payback comes from the Fed and state rebates which knocked about 50% off the cost of the system.

Overall I generate up to 1500 kWh in the best months and my total yearly bill was about $600. In the peak months I used around 2500-2800 kWh, so subtracting the 1500, I only had to pay for 1200. That is key as we have a very progressive tier system of electric rates. It's only smart to cover tier 3-5 with solar/wind power at this time, as tier 1 in the LA area is below $0.10/kWh.

Without solar I would have probably spent an additional $3000-4000 on electricity.

From what I've read above about NorCal they are even more screwed than we are here. Solar and wind would make even more sense there.