? KWH per month from grid tied 17' & 20'

[Timeless Turbines]

     I just got my energy bill, 550 kwh for my 2400 sq ft home in michigan. I will be building the 20 footer with batteries and grid tied.

[Perry1]

What do you mean by batteries and grid tie? If your grid tied why would you buy batteries as well?

Perry

[Bruce S]

Perry;

With grid tie & batteries, he can charge the batteries while feeding the grid. Of course with this setup he'll need approved switching system that dis-engages the inverter from the grid so when the lineman go working on the problem they don't get fried.

Makes for a good home backup for those times when the lake effect snow take out another transformer.

However, it will need to be signed off on by an EE otherwise P&L and insurance will have a field day.

I don't have a grid tie system, 100watts of PV just won't do it :-), but I do have a few circuits that are disconnected from house power just for these times.

before UE would sign off on them I had to prove they would not kill someone, plus had to use AC plug-ins that are different in color than ALL the rest

Hope this helps;

Bruce S

 

[wooferhound]

If you have batteries with your Grid Tie system, then you will be able to have backup power if the Grid goes down.

[Timeless Turbines]

I am ok with swapping out my batteries every couple of years, as a trade off to buying them.

I have 30 100lb 12 volt deep cycle batteries that gives me 5,000 AH cap.I got for free from my Batteries Plus rep. There used from a corporate i.t. room. Batteries Plus changed out there batteries and gave me the old ones. The corp. changes them out every three years, the next month Batteries Plus offered me 80 hospital bed batteries ( two years old ) but I was not ready for them yet. The batteries I got are the highest quality that that company made , no recycled lead.

Batteries Plus does not sell used batteries, they were happy to help.

[ghurd]

Some of the numbers don't quite line up in my mind.

The battery numbers imply 167AH at 12V?

And 5000AH capacity implies a 12V system.

A 20' 12V is pretty ridiculous?

There are not many 17-20'-ers out there.

Not likely to get any guesses as to what to expect.

G-

[Timeless Turbines]

    Ghurd,

 Please Help me out with this.

I have 30 12 volt batteries, I am shure right now I would wind me stator for 240 volts and use 20 of my 12 volt batteries in series,

They are rated at 140AH @ 10 hour rate. 20 X 140 = ? oops

So its been along time sence I thought about this stuff.

I am thinking the series is still limited to ??.

How meny amps could I draw over a 10 hour peroid if full, and only draw out half or less. I still think 20 X 140 = 2800 AH

[Dave B]

  Forget grid tie, charge and use your batteries for as much power as you can, not just as idle backup. Grid for charging at times sure and maybe a backup generator. Make your own power, use your own power and use less grid power. Take a real good look at the math for selling your power that you will probably need !

  Just an opinion after I've worked the numbers, your area may be better or even worse.

  Dave B.

[ghurd]

The AH rating is how many amps can flow through (out of) a full battery before it is dead.

In series, All the amps flow through All the batteries.

Twenty 12V 140AH is still 140AH, but a 240V 140AH.

And 240V x 140AH = 33.6KWH of power.

Twenty 12V 140AH in parallel is still 12V, but 2800AH.

And 12V x 2800AH = 33.6KWH of power.

Batteries hold a fixed quantity of power.  12V x 140AH = 1680WH.

And 20 hold 1680WH x 20 = 33.6KWH.

They can be arranged to different voltages, but the "power" is the same.

Draw out half, at the 10 hour rate, is half the rated 10 hour amps.

The 10 hour drain for 'dead' is 14A.  (140AH / 10H = 14A)

Half is 7A.

That ignores the Peukert effect, temperature, etc.  But 7A is close enough!

G-

[wooferhound]

That is exactly my thoughts. If you are making less power than you are using, then why are you trying to sell it. It costs more to make your own power than to buy it from the grid, not to mention that the utility pays out at a lower wholesale rate. So use all the power you make and supplement that with grid power.

[TomW]

Woof;



So use all the power you make and supplement that with grid power.

Exactly my way!

Be nice to have a net metering setup but my current gear doesn't do that so I just try to manipulate my loads so I use the various power levels I collect. Being a moving target it takes some forethought and effort but works for us so far.

Tom

[Dave B]

Woof & Tom,

  Great to hear you tend to agree, make your power, use your power, control your own power.

 There is a very strong thought process for many home owners that selling power back is "sticking it to the grid". The power companies could not be happier with this as well as the incentives that fuel this win, win, win, for the utility.

  Unless you can generate far more power than you use it would be wise for many to really take the time and do the math for their area before grid tieing. The grid obviously hopes that the incentives and very strong psychological thought of "sticking it to the grid" will win over this wonderful attribute we have called thinking.

  Each KWH I generate is worth the same amount to me as what the grid would charge me. I have this quiet calm about using less grid power and watching the tail wag the dog.

  If the idea of generating power for the grid works for you then by all means allow the grid to use your power. For me, I will continue to use all of my own generated power and rely less on the grid.  

Dave B.

[Timeless Turbines]

     Sorry For the delay in my responce.

I have started a new small business to pay for building a 20 footer, I got a $400.00 a month pay cut in Dec.

 My Goal for grid tie is to use it as a storage system, in Michigan the utility set up is 12 month net metering, spin the meter backwards and take up to 12 months to use it, and if you don't, you loose it.

 Six months ago the 17 footer people were swaping, out put totals and grid tied set ups were harvesting twice as much power. I think the batteries slow things down.

 For me it is convenience, and and braging rights, I got no kids, and I have wanted to build a very fuctional turbine sence 1980, 30 years is to long. I am an electrician so that should explain it.

[Timeless Turbines]

  Ghurd

Thanks, I have been so busy, and I cant hardly beleave that I have lost so much and not able to spit that info out, right on the money. Its embarrassing.

 Thanks Larry.

[Dave B]

 Unless you have a very unusual set up I have to believe you will be using power at the same time you are generating power. To "spin the meter backwards" you will have to generate more power overall than you use. If you can do this then that is great, I wish you luck.

 Economics seem to play a big part of this for you now. Sticking it to the grid can be an expensive feel good. I think it might feel even better to use less of their power and more of your own.

 Just my opinion after crunching the numbers here. Good luck with your project and keep us posted.  Dave B.