# Solar PVC (because there simply aren't enough threads, lol)



## Warwalk (May 25, 2011)

I've been closing in on my property for two years now, and for the first time, rather than looking at more years, and looking at only a few months. 

This is for the big island of Hawaii, and rather than focus on issues such as "how much solar do I need", or "is solar right for me", I'd settle by saying for the first question I'll have to find out once I get there, and for the second question there's simply no other choice ~ there's no grid tie whatsoever, nor will there be for awhile to come.

That being said, I look to more practical matters... what are some reputable sites for purchasing solar panels, that offer a decent mix of cost per watt vs reliability? I've heard in the past that the best way to "do" solar is to buy it once and be done with it. I wish I had this luxury, but I don't. For me, by necessity, I'd be buying enough to power a periodic getaway, that would ultimately morph into a vacation home, and ultimately a place to live permanently. 

I think I'm just rambling at this point... best come up with decent questions quickly... okay, the aforementioned "good sites" to buy in bulk... any ideas? Also, periodically I see these articles about building one's solar panels... any benefit to doing this? I'll have no choice but to re-size later, so I'll almost have to learn to do it myself to cut my expenses as I up-size inverters. What do battery banks run? I've seen them for $300 each, which sounded crazy high, but maybe not...


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## Warwalk (May 25, 2011)

... just for giggles, I'd guesstimate I'd use 800 kwh /month on the absolute high side... and only then if I sprung for some form of AC / dehumidification... no dishwasher, no drier...


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## wy_white_wolf (Oct 14, 2004)

800 KWH monthly = 26.7KWH daily average

Insolation for Honolulu has a low of @4hours http://www.gaisma.com/en/location/honolulu-hawaii.html

Being off grid you will also have to account for system losses. A system this big is going to require an MPPT controller. So:

26.7KWH / 0.8 = 33.4KWH / 4H = 8.35KW is how big your arrayneeds to be.

You should not draiin your batteries more than 20% in one day. That will also give yo 2.5 days atonomy before hitting the 50% discharge level that you should never go below. So:

33.4 * 5 = 167KWH battery bank 

That's 13,916AH at 12V
6958.3AH at 24V
3479AH at 48V

On the mainland that would cost you around $75,000 to $100,000. Expect prices to be inflated for Hawaii.

Might look into doing things without electricity to get the size down to something managable.

WWW


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## TnAndy (Sep 15, 2005)

wy_white_wolf said:


> A system this big is going to require an MPPT controller.


Or more like 2 to 3. I have 2 Outback 60amp and one 80amp on a 6kw system.


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## TnAndy (Sep 15, 2005)

Warwalk said:


> ... just for giggles, I'd guesstimate I'd use 800 kwh /month...


You'll quit giggling when you get our your checkbook for 800kw/hr/month. 


Here in Tennessee, I set up a 1500w (panels) 3500w (120v inverter) 800amp/hr (24v) battery system for a buddy's off grid place ( no labor, just materials ) for about 8,000 bucks. It generates about 7kw/hrs on sunny days. He has a diesel genset for backup.

IF you did all the work, and cut back some on the battery backup, you could probably get by on 40-50k.


And lastly, no, you can not build the panels for a system like this.....either from a price standpoint or a quality standpoint.


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## Warwalk (May 25, 2011)

This is what I was afraid of, but I don't really see any other way around it if I'm going to get property out there. Potentially I can scale back on some things (no dishwasher, no dryer) but at the least I'm hoping to have a whole house dehumidifier and a wall air conditioner... who knows, maybe even this would be too much for such a system. The area I'm looking at has far less insolation than Honolulu (which is actually a very sunny city). Where I'm looking it would be more like Seattle... 

I wonder, energy saving devices aside, are there ways of scaling down the cost? Smaller battery bank perhaps? (Night time lows are in the 60's so possibly we could get by on fans if the air was already dehumidified for the night-time hours)...


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## Jim-mi (May 15, 2002)

From a couple guys who have design /installation business's out in HI you are going to probably get sick of the permits $$$$$ required by most all of HI.

"whole house" is a scary expensive term.........

Yes all those things (requirements) are quite easy to do............

But you best be sitting down when you see the price tag to do so...........................


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## Warwalk (May 25, 2011)

@Jim-mi ~ do you mean you yourself are out there, or friends of yours? I'd really look forward to putting together a list of subs, or at least shake a few hands via phone / e-mail and see who does what.


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## Jim-mi (May 15, 2002)

Well I'd like to be out there, but no I'm in Michigan.
The conversation is through a list I am on of designer / installers..
I do not believe it would be ethical for me to give out their email addy.
Do a giggle search for Solar business in HI and see what you come up with.
These guys put in some substantial size systems. Don't be put out if they are on the reluctant side to walking a do-it-your-selfer thru the whole ball of wax.........
And yes there business relys on making a buck on equipment sales when they are installing a whole system.
An advantage to buying equipment thru them is shipping.
They have gone thru the hassle of shipping company DAMAGE.............


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## Warwalk (May 25, 2011)

I agree with you completely Jimmi. Back when I had my insulation company, I was always amazed at the questions people would call me with (how much I paid for material, where I bought it, etc...). I normally explained as politely as possible that I would gladly give them a quote for the work, but I simply didn't have the time to walk someone through all the nuances of doing it themselves. Still, insulation, when compared to solar, was a fairly basic setup: There were limited choices from limited manufacturers, and the end product was pretty predictable in terms of its' performance.

Solar has proven much more difficult. There are numerous panel makers, and the overall cost in some cases can approach the cost of the house itself. Even then, there's never a guarantee that the product will work as well as what one would hope for. It's for these reasons that I read the boards, marvel at TnAndie's setup, and wonder if it could be right for me (in this instance, I really don't have much choice... there's no grid-tie, nor will there be any time in the near future).

It's also difficult comparing apples to apples when people say "start with your prior energy bills", as suburban Houston will have a drastically different energy footprint than rural Hawaii, so really what I'll have to do is estimate from the ground up, counting average lightbulbs on, and for how long, energy to recharge phones, to run computers, etc... and even then I'm not entirely positive I'll be in the ballpark. 

Still, I appreciate all the feedback as it comes in. It's good information for when I get closer to time. One final thing I try to keep in mind is that it's my understanding if I'm to make use of rebates I'll have to be working through a licensed installer... not positive on that yet or not.


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## Gray Wolf (Jan 25, 2013)

HI components from Asia may be cheaper and just as good as the stuff we have on mainland. Inverters are HEAVY, panels and mounts are bulky and shipping costs to HI may well make reccomendations and cost comments from us something to take with a grain or two of salt. Local retailers and/or installers in HI may be your best bet. Also, now's the time check on HI incentives in addition to federal tax credit. Incentives are usually different for grid-tied and stand-alone systems so read the fine print.

Good luck!


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## Jim-mi (May 15, 2002)

There is some really great deals ---price per watt---to be had on PV panels right now......
Then comes the monster..............shipping . . . . . . .and all the real life facts of shipping damage....
What you can get delivered to Tx might be a good deal . . . but now to get it to HI . . . . 
I try to stay with American made products -----when possible..
I have heard that there is some hidden import type charges on most of the china made PV panels . . . . .and that becomes a shock to buyers who are not aware of said charges.........
So it makes a whole lot of sense to employ a "local" designer / installer . . . .all equipment arrives at your door step. ready to go.......and as such the local guy is not going to sell you truck stop junk
Many DIY'ers have to learn the hard way that the cheap stuff is money forever lost

Now back to your paring down on your electrical usage..................


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## tarbe (Apr 7, 2007)

Jim-mi said:


> There is some really great deals ---price per watt---to be had on PV panels right now......
> Then comes the monster..............shipping . . . . . . .and all the real life facts of shipping damage....
> What you can get delivered to Tx might be a good deal . . . but now to get it to HI . . . .
> I try to stay with American made products -----when possible..



I have enjoyed reading this thread.

Reminds me of many of the arguments I have personally gone through during my analysis of whether solar makes sense for my application in Ozark County, MO, on the retirement place.

I do believe I could make a good argument either way!!

For me, the up-front cost of getting grid in (about $10k) plus my strong desire to avoid commercial entanglements and the dependencies they create, powerline easements and power outages has swung the argument in favor of solar. 

The issues with shipping has me wondering if I should focus on finding a local Houston purchase point for the panels?

I won't be ready to install for probably 3 years...but the more I study the situation, the more I am thinking the time to move is now!


Tim


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## Jim-mi (May 15, 2002)

delete


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## DryHeat (Nov 11, 2010)

DW and I are looking at putting a grid-tied system on our roof this year. The fellow we're dealing with swears by using mini-inverters (one per panel), but maybe that's for grid-tied exclusively? Anyway, you might look at those as another option, using them keeps each panel independent of the others so damage, shade, etc on one won't cut output from others.


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## TnAndy (Sep 15, 2005)

The micro inverters ARE grid tie only.


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