Worth grid tie for 30 cents/kwh???

[CoolBreeze]

Hawaii (my home state) has just committed to introducing a feed in tariff program for small

renewable energy producers. I believe the PUC is forcing a reluctant utility to buy electicity

and at  "rates that will exceed current electricity prices" (a quote from the local newspaper)

Current consumer rates for elecricity in Hawaii county are $.31/kwh. Apparently the PUC

will be providing more details about the program in the coming months.

I am reserching building my own turbine(s) for the sole purpose of feeding

the power to the grid under this new program.

I am tentatively shooting for an array of turbines to produce an average

of 10kwh per hour using about ten turbines.

I have ordered the Homebrew Windpower book by Dan and Dan and have the help of a machinist.

I have a background in electronics.

I am looking at three different sites for the turbine installation.

Site 1: one acre (about 125x380'),bare rock, no obstacles,mean wind speed 11.2mph-12.3mph,

cost= 20k, zoned residential.

Site 2: 14k square feet, scrub brush with max tree height at 8 feet, mean wind speed

14.5mph-15.7mph, cost=35k, zoned residential.

site 3: 12k square feet, scrub brush with max tree height at 30 feet, mean wind speed

11.2mph-12.3mph, zone residential.

site 4: three acres rectangular shape, bare rock, no obstacles, mean wind speed 11.2mph-12.3mph, cost= 40k,

zoned agriculture.

No site  receives salt spray from the ocean. Rainfall for all sites is about 20"/year.

I'll try to locate some local wind enthusiasts on the island next week but in the meantime

I would appreciate any advice regarding the following:

site choice, PPA (power purchase agreement), feed in tariff, batteries or no batteries,

building permit. Thanks

[freejuice]

Hi, If you are at 31 Cents a KW, I beleive you would be a good candidate for wind/solar.

 I'm at 16 cents here in SC, but we have to run the Air conditioning/heat pump to keep from roasting in the blistering summmers...I could probaly survive without it, but it might make wifey's attitude ill as a hornet.

 I just recently built the 10ft machine in their book, and yesterday on the test stand ( first time) it was indeed very very quite when it reached battery charging voltage, so if local regulation allow, you should not have any complaints from neighbors about noise....However with that said, I believe some power companies are very fickle about what you can and not grid tie...so as you are doing, keep after the homework on the topic locally.

 Yet, that does not mean you cannot go off the grid for much of your power use, at 30 cents a kw it would probably be worth while....especially if you use enough power which approaches 250+ dollars a month..

 I guess the biggest question is, what is your transistion point in which you say enough is enough and start fighting that monthly power bill....but from what I can tell by the scheme of things, to sell back to the grid for a profit will be a long hard road...solar or wind

 Around here they can buy your power two ways ( your choice), at a huge discount of 4-5 cents a kw or you can net meter, for a KW to KW exchange for a small monthly fee to stay connected to the grid.

 Essentially I'm an newbie to this game too, but I can assure you there are some real pros around here that have been in this game for a very long time. They are a wealth of knowledge....they have helped me so many times

They have built some really big machines around here, and you could probably get by with less machines for 10 kw an hour.

 good luck,

 Gavin

[Dave B]

Cool Breeze,

  An interesting and we feel very worth while project for sure. We have experience with 12, 16, 18 and now 20' axial machines based on the basic design.

  Easier than searching send us an e-mail here at bruggelog@netsync.net We would like to help you.

 Thank you, Dave B.

[CoolBreeze]

Thanks for the input. After searching and reading the posts here I still have many questions.

At this point We intend to put together two 10' turbines based on the free online plans at OTHERPOWER to get an  understanding of connecting multiple turbines together. If the turbines perform as expected and permitting, and everything else comes together, larger turbines may make sense.

Questions:

1. Does the Ginlong (or other) inverter accept unfilterd DC from a 3 phase home wound alternator?

I thought I read these grid tie inverters can be used without batteries. Does this also imply no need for external filter caps. If batteries or caps are required. What are the design considerations? I intend to use the batteries only for filtering (if required by the inverter) and not for home power storage.  

http://www.ginlong.com/grid-tie-connected-inverter-controller.htm

2. Is there a commercial inverter or other off the shelf control circuit that allows for easy hookup of dump load resistors. Again this circuit/inverter would be dumping directly from the turbine(s) and not a battery bank???

   
   

3. Has the Ghurd dump load circuit been succesfully scaled up to dump current from larger turbines in the 10' to 20' range? Links??  

   
   

4. If there are muliple turbines and one is producing say 200Vdc with 20V of 3Hz AC ripple and another is producing say 100Vdc with 10V of 1.5Hz AC ripple can these DC voltages be connected in paralell?? Are there limits to connecting DC outputs in paralell?

   
   

5. Given the wind site descriptions in my previous post is there a turbine size sweet spot for efficiency and/or cost effectiveness?

   
   

6. Can the turbine plans in the Homebrew Windpower by Dan and Dan (should receive my copy tomorrow) be modified to produce an acceptably high DC voltage to feed a grid tie inverter?

   
   
   

7.Ideal DC voltage should be as close to grid voltage as possible for minimal power loss?  

 

[CoolBreeze]

Thanks for the input. After searching and reading the posts here I still have many questions.

At this point We intend to put together two 10' turbines based on the free online plans at OTHERPOWER to get an  understanding of connecting multiple turbines together. If the turbines perform as expected and permitting, and everything else comes together, larger turbines may make sense.

Questions:

1. Does the Ginlong (or other) inverter accept unfilterd DC from a 3 phase home wound alternator?

I thought I read these grid tie inverters can be used without batteries. Does this also imply no need for external filter caps. If batteries or caps are required. What are the design considerations?

I intend to use the batteries only for filtering (if required by the inverter) and not for home power storage.  

http://www.ginlong.com/grid-tie-connected-inverter-controller.htm

2. Is there a commercial inverter or other off the shelf control circuit that allows for easy hookup of dump load resistors. Again this circuit/inverter would be dumping directly from the turbine(s) and not a battery bank???

   
   

3. Has the Ghurd dump load circuit been succesfully scaled up to dump current from larger turbines in the 10' to 20' range? Links??  

   
   

4. If there are muliple turbines and one is producing say 200Vdc with 20V of 3Hz AC ripple and another is producing say 100Vdc with 10V of 1.5Hz AC ripple can these DC voltages be connected in paralell?? Are there limits to connecting DC outputs in paralell?

   
   

5. Given the wind site descriptions in my previous post is there a turbine size sweet spot for efficiency and/or cost effectiveness?

   
   

6. Can the turbine plans in the Homebrew Windpower by Dan and Dan (should receive my copy tomorrow) be modified to produce an acceptably high DC voltage to feed a grid tie inverter?

   
   
   

7.Ideal DC voltage should be as close to grid voltage as possible for minimal power loss?  

 

[ghurd]

The Ghurd controller is being used with some 10' and larger,

but you should not have a dump load in that situation.

The grid inverter should send all the power being made to the grid.

If the grid goes down and can not accept any power, then something like a Ghurd controller can be used to shut the windmills down.

Might be something useful here,

http://www.fieldlines.com/story/2009/3/19/165655/623

G-