Forums > Specific Focus > Home, Garden & Construction in Mexico

robt65

May 11, 2011, 11:28 AM

Post #1 of 12 (3507 views)

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Costco Solar Panal Kits for the Home

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Has anyone bought and use these solar pane kits that Costco sells for their home? Are they a pretty good deal? do they collect enough energy to really make a difference in the CFE bill? I would like to hear anyone's personal experiences with these units. How many units are needed for a home? How does one go about figuring out how many of these kits are needed for one's home? What are the pros and cons? Thanks in advance.

robt65

Rolly / Moderator

May 11, 2011, 11:52 AM

Post #2 of 12 (3490 views)

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Re: [robt65] Costco Solar Panal Kits for the Home

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Look here.

Rolly Pirate

robt65

May 11, 2011, 12:02 PM

Post #3 of 12 (3485 views)

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Re: [Rolly] Costco Solar Panal Kits for the Home

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Thanks Rolly,

I already have that internet site, but have you heard of anyone using them? Are they sometyhing that would pay for them selves in a reasonable time?

Robt65

johanson

May 11, 2011, 12:14 PM

Post #4 of 12 (3482 views)

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Re: [robt65] Costco Solar Panal Kits for the Home

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Although you ask a very good question Robert, it would take a great deal more info from you about your expected daily electrical usage to even guess on the number of panels needed. Also, if I remember right, these Costco panels are tied into their own independent battery system rather than being connected to the local power grid.

In my case, I have twenty-two 180 watt panels that are capable of generating as high as 26 KWH DC per day, the best I have seen was 25.2. It probably averages close to 23.5 per day during the dry season.

The first thing my system needs to do is invert this to AC. In the process, I probably loose about 20% of the KWH. I'm hooked up to the power grid so during the sunny day I sell my excess electricity to CFE(the electric utility) and during periods when there is little to no sun, I buy back electricity.

As a result of these panels I keep my usage down to about 100 KWH per month or 200 per billing period. This means that I am not paying at the very high DAC rate but in my case because of my geographical area, I am charged at the tariff 1 rate.

So rather than paying many thousands of pesos per billing period I pay close to 200 pesos per month.

Why do I use so much electricity? There's the swimming pool motor, the pressure pumps needed to run the irrigation system for 3/4 of an acre, a big screen TV, etc

Oh and some power is needed to keep the deep cell golf cart batteries charged to give me power should there be a short power outage.

What's the return on investment? Forgetting the battery backup, if my projections are correct, 8.5 years.

chicois8

May 11, 2011, 7:17 PM

Post #5 of 12 (3445 views)

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Re: [johanson] Costco Solar Panal Kits for the Home

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So do you have battery storage( how many) or are you just using solar panels during the day and buying electric from CFE at night??? 22 panels??

johanson

May 11, 2011, 7:31 PM

Post #6 of 12 (3438 views)

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Re: [chicois8] Costco Solar Panal Kits for the Home

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I have eight 6 volt golf cart batteries. I've never had the power out long enough at night to draw down the batteries very much.

Often when the power has gone off I didn't even know it until I viewed the electric clock in the kitchen on the Microwave oven which is on another and unprotected phase in the kitchen

YucaLandia

May 13, 2011, 2:01 PM

Post #7 of 12 (3398 views)

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Re: [robt65] Costco Solar Panal Kits for the Home

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60 Watts from clean panels, operating 8 hours a day, at $2.6 pesos per kW-hr translates to an optimistic $1.25 pesos per day for our Intermedio rates. That roughly translates to a best-case-scenario payback in 11 years, if you use all the power generated; if you do not let dust or dirt accumulate on the panels; and if nothing breaks or wears-out. The unit has a fairly small battery for storage, and it includes a 200W (small) inverter. This means that the panels + small inverter would power one medium floor fan at low speed while the sun is shining strongly.

If you are living a 12V lifestyle on a boat or out of an RV, using very little power, then this system would light a few lights, play the radio, and run a small fan or two. (e.g. Inexpensive inverters like this one run at about 80% efficiency, so, some folks skip the inverter and use the system to run 12V devices.)

We're setting one friend's Costco system to supplement the 12V batteries in his office UPS & to power some 12V outdoor path lighting. . . . Ironically, our typically reliable power has had 3 little 100ms drop-outs as I was editing this post, so, maybe you could include the $$$ savings in your cost-recovery calcs, from not having to take extra time to re-type things during power outages.
steve
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Read-on MacDuff
E-visit at http://yucalandia.com

(This post was edited by YucaLandia on May 13, 2011, 2:14 PM)

salto_jorge

May 15, 2011, 10:23 PM

Post #8 of 12 (3333 views)

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Re: [YucaLandia] Costco Solar Panal Kits for the Home

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I have two sets of these 45 watt panels (six total, 2 regulators) ) plus 4 of the smaller 5 watt panels (needed their own regulator) .
The batteries are connected to a bank of 4 - 12 volt gel cells plus 2 deep cycle marine batteries.
This configuration is used to power 12V (RV) lights at night using a day/night sensor/switch.

If one wants to be off the grid so to speak, you would need commercial panels (80-150 Watt) plus an expensive gel-cel battery bank.

The systems being installed in the states are used to feed power back into the power grid and are not connected to any storage units. So at night one is using power off the grid.

Here is a link to a solar power calculator.

http://www.freesunpower.com/easy_guide.php

http://www.freesunpower.com/battery_designer.php

(This post was edited by salto_jorge on May 15, 2011, 10:43 PM)

chinagringo

May 16, 2011, 7:09 PM

Post #9 of 12 (3279 views)

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Re: [robt65] Costco Solar Panal Kits for the Home

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Given the relative high cost of the battery system versus having a generator for those periods when one is totally without power, I cannot figure why one would go the battery route.

This entire topic has been enlightening not only about solar options but also dealing with the DAC rate from CFE! It would seem to this amateur that the route that David went with no batteries and quite simply get them down into the basic rate would be one of the best options. Then again, I have never understood the fixation to living off the grid. It reminds me of the fixation that Americans have with gas prices/gas mileage when they still enjoy some of the lowest gas prices in the developed world.
Regards,
Neil
Albuquerque, NM

johanson

May 16, 2011, 7:34 PM

Post #10 of 12 (3274 views)

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Re: [chinagringo] Costco Solar Panal Kits for the Home

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I agree, using batteries when you have the option of connecting to the net is not very cost effective. In fact the only reason I have these batteries, is not to keep off the grid, but to have a whole house (single phase) un-interruptible power supply which is great for the modems, computers, TVs etc. But for long power outages I'm wired for a 2 phase generator. It's just that I have not needed the old generator, that we used to have to use all of the time more than 10 years ago, since I installed the panels and batteries. And since electrical reliability in my neighborhood is so much better than it used to be.

salto_jorge

May 18, 2011, 8:00 AM

Post #11 of 12 (3239 views)

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Re: [johanson] Costco Solar Panal Kits for the Home

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Keeping that battery bank charged.

If you have a small PV setup using batteries consider a 12V Power Inverter / Charger.

One of these 500/800 watt units will insure that your battery bank is charged just in case your P/V panels cannot.
Just plug in the AC line once a week or have it hooked to a heavy duty timer like one uses for christmas lights.
After a good full day of sun light the bank should be charged, thus have the time go on before it gets dark.

(This post was edited by salto_jorge on May 18, 2011, 8:01 AM)

Sculptari

May 24, 2011, 9:10 AM

Post #12 of 12 (3173 views)

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Re: [salto_jorge] Costco Solar Panal Kits for the Home

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I am also setting up solar, for housewide 12 volt led lighting and emergency reserve. From many years of RVing and boating, I have collected a legacy of high quality equipment, too nice to give away. Also, the wide variety of lighting and equipment in 12 volts is amazing - especially the LED products like available here http://www.ledlight.com/ - look at the lifespan of this products, you can now easily put lighting in hard to access locations. Neil - generators are always a real pain. Gasoline today only keeps it's octane for 6 weeks, and the additives are not meant to sit in a tank or carburator for any length of time, the commercial fuel additives, from my experience, do not work. Diesel is better. The only real fuel option for a generator is propane. The internal combustion engine is a failure in so many ways.

(This post was edited by Rolly on May 24, 2011, 9:38 AM)