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DanGair

Sep 12, 2009, 11:01 AM

Post #1 of 18 (8325 views)

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Solar Supplies and Grid Tie Info

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I am interested in doing some business designing and installing solar electric systems in Mexico and am looking for resources for supplies, particularly panels, cc's, and inverters. I'm located near Vallarta but also travel to the SM/GTO area regularly via Ajijic/Guadalajara. I'm also searching for information on grid tie issues and any possible incentive programs.

Thanks!
MexDog



johanson / Moderator


Sep 12, 2009, 7:13 PM

Post #2 of 18 (8296 views)

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Re: [DanGair] Solar Supplies and Grid Tie Info

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Darn I responded to your post, hit the wrong keys and to make a long story short, I'm writing it again. I was hoping someone else might have been able to help you with better info than what I am about to give you. I have a ten panel, battery back-up, grid sell-back system that was installed better than a year ago. On a perfect day, I can generate almost 12 KWH . Sadly although the folks who installed the system were led to believe by their suppliers from up here in NW WA., that the system met Mexican specifications, you know not 115 to 120 Volts AC, but 127 +/- 10% volts. It did not and often the additional KWH generated could not be sold back to the grid, because my system voltage was too low. This year, my system received a hardware upgrade and I am now selling my excess KWHs back to the power company, CFE. I live along the shores of Lake Chapala and we are lucky to have a green group, which of course, is called "The Lake Chapala Green Group". One of the local (Guadalajara) experts who has often come to lecture to our group about solar energy is Jsun Mills (Yes, that is how you spell his first name) who is bilingual and sells solar products. Jsun was instrumental in getting my system updated to not US but Mexican power specifications. If you were interested in having a system, be it a photo-voltaic or a hot water solar panel system, in your home, I would recommend him. You might want to email him. Jsun is a font of information J Mills <jmills@alta-energia.com>


DanGair

Sep 12, 2009, 8:06 PM

Post #3 of 18 (8283 views)

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Re: [johanson] Solar Supplies and Grid Tie Info

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Excellent. Thank you. I'll contact Jsun and start looking into higher voltage grid tie inverters. It's great to hear that buy back is actually possible. I had contacted CFE about it once but didn't get very far. I'm curious, did you have to make special arrangements with them locally, or is there a national policy? Would also love to know how much they're crediting you.

Thanks again!
MexDog


johanson / Moderator


Sep 12, 2009, 8:29 PM

Post #4 of 18 (8281 views)

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Re: [DanGair] Solar Supplies and Grid Tie Info

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Good questions. First I am an energy hog: you know a pool, a fountain, and all those stupid things that use power, things I don't really need, but want. So of the 9 to 12 KWH I might generate, I use much of it up and only sell back maybe 1 to 4 KWH per day on one phase. But because I have a three phase system, I purchase much more than I generate

Now understand, I had to purchase a digital meter from CFE specifically for persons selling back power. I have one set of numbers that increase as I use power and a second set of numbers that decrease as I sell back power to the grid. I am not allowed to sell back more power than I use.

And who contacted CFE and did all of the paperwork? Jsun, of course. It is my understanding that the sell-back policy is nation wide, but that only a few offices have had to deal with this issue.


DanGair

Sep 13, 2009, 4:03 AM

Post #5 of 18 (8263 views)

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Re: [johanson] Solar Supplies and Grid Tie Info

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Fascinating, and all great info. What kind of panels do you have? I'm guessing they must be 200 watt? And what is the actual rate (pesos per kw) that CFE is paying you when you do produce excess?
MexDog


johanson / Moderator


Sep 13, 2009, 8:10 AM

Post #6 of 18 (8253 views)

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Re: [DanGair] Solar Supplies and Grid Tie Info

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I don't remember the name and cost per watt of the solar panels and I'm in Seattle right now. So sadly I can not check.

You asked, "What CFE is paying you when you do produce excess?" It doesn't quite work that way. Rather the amount you generated and sent back into the grip is subtracted from the amount you consumed. And then you are billed for the net amount consumed based upon normal CFE rules.


RickS


Sep 13, 2009, 11:33 AM

Post #7 of 18 (8247 views)

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Re: [johanson] Solar Supplies and Grid Tie Info

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Then under those circumstances, the "repay" rate is the rate you are charged for a kwh.... and in your case I recall you pay a high rate since you are a high kwh consumer.


johanson / Moderator


Sep 13, 2009, 12:38 PM

Post #8 of 18 (8238 views)

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Re: [RickS] Solar Supplies and Grid Tie Info

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I do pay the high or DAC rate which is 2.896*1.15= $3.33 pesos per KWH this Sept. But imagine if I had just the right # of panels to take me out of the DAC rate. Not only would I be saving power at the DAC rate but also would be paying the remainder of my power at the Tarifa 1 rates which are appreciably lower than DAC rates. I'm not there yet.

For more info go to

http://www.cfe.gob.mx/es/informacionalcliente/conocetutarifa

It's in Spanish but not too hard to figure out.


RickS


Sep 13, 2009, 3:47 PM

Post #9 of 18 (8226 views)

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Re: [johanson] Solar Supplies and Grid Tie Info

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$3.33 pesos per KWH

Wow, that's 25 cents per kWh! Where I live (Colorado) my rate is around 6.7 cents/kWh for usage under 1400 KW per month and an extra 3 cents per kWh if over that. Then there are some fixed charges amounting to about $6/month plus 6% of the total usage cost.

I realize that you are paying DAC and I always knew electricity was expensive in Mexico, but......


johanson / Moderator


Sep 13, 2009, 4:07 PM

Post #10 of 18 (8223 views)

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Re: [RickS] Solar Supplies and Grid Tie Info

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So many things are cheaper in Mexico. Like my meds. What's a 1.75 liter bottle, of a good diuretic like Bacardi rum cost? I paid 195 pesos at the new Costco. Here in Seattle it's almost twice that.

Back to electricity; there is a monthly DAC rate charge as well of $68.16 plus 15% sales tax or more than $78 pesos per month fixed charges when you are in DAC.


DanGair

Sep 13, 2009, 6:14 PM

Post #11 of 18 (8212 views)

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Re: [johanson] Solar Supplies and Grid Tie Info

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What does DAC stand for? I thought there were three or more levels, or are there only two?
MexDog


johanson / Moderator


Sep 13, 2009, 7:00 PM

Post #12 of 18 (8206 views)

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Re: [DanGair] Solar Supplies and Grid Tie Info

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You are asking good questions. And your assumption is both right and wrong :) Dependent upon where you live, you are assigned a specific tariff rate. Up high in the mountains were I live, we are charged at tariff rate 1. Should you live somewhere else you will be charged at one of these rates. Sadly I do not have a map showing dependent upon where you live what, your rate would be. What I know is that there are the following rates

Tarifas específicas Domésticas 1 1A 1B 1C 1D 1E 1F
As I wrote above, where I live, we are charged per the Tariff 1 tables. Down at sea level, you are going to be charged at one of the other rates, you know 1B,1C,1D,1D,1E, or 1F as explained above.

Now each tariff table has 2 to 3 different rates dependent upon your consumption, and should you use too much electricity, then you are no longer charged at the tariff rates shown above, but at the DAC rate. What is the DAC rate? It stands for
"Domésticas de alto consumo" You know residential table for those who use too much power.

So if you use too much power by the electric company's definition, you are no longer charged at rates 1,1a,1b,1c,1d,1e etc rather you are charged a much higher rate for each and every KWH consumed.

For a better description of the above, I would highly recommend that you visit
http://www.cfe.gob.mx/es/informacionalcliente/conocetutarifa

It's all there. It is explained in great detail. Sure it's in Spanish, but numbers are the same in each language and words like
informacionalcliente
Tariffa
KWH

are easy to decipher. Check it out. Good luck


(This post was edited by johanson on Sep 13, 2009, 7:03 PM)


rockydog85251

Sep 13, 2009, 7:45 PM

Post #13 of 18 (8199 views)

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Re: [johanson] Solar Supplies and Grid Tie Info

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Can you all out there please advise where you live and if the government subsidizes your electric rates in the summer?
We live in Mazatlan and get an almost 50% reduction for the summer months, unless you are a high user....more than an average of 1,000 KWH per mo. on a revolving annual average basis. Just curious is this a a localized "thing" or is generally applied to the entire Republic?
Thanks.
Willie


johanson / Moderator


Sep 13, 2009, 8:29 PM

Post #14 of 18 (8190 views)

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Re: [rockydog85251] Solar Supplies and Grid Tie Info

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Really folks, it's all on the web page I referred to above. You know

http://www.cfe.gob.mx/es/informacionalcliente/conocetutarifa

Well that is not quite true. What it explains is per tariff rate 1, 1a, 1b, etc, how much the reduction is. It's all there. Really. What it doesn't do is identify by geographical area what your tariff table would be

In the greater Lake Chapala and Guadalajara area which is tarifa 1, we have the same reduction be it summer or winter, if the user, consumes less than 3000 KWH during the previous 12 month period. For those of us who use more, and most of us from North of the Border (NoB) do, we are not given any reduction. We are simply charged at the much higher DAC rate as explained at

http://www.cfe.gob.mx/es/informacionalcliente/conocetutarifa

Please take a look at this. It was confusing to me at first. Now it makes sense. Sure, it took several hours of study or experimenting around clicking on the various links at the above URL. But now it makes sense. And it will do for you too. You just need to spend a little time studying the above URL, you know, the above link.


Papirex


Sep 13, 2009, 8:51 PM

Post #15 of 18 (8189 views)

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Re: [rockydog85251] Solar Supplies and Grid Tie Info

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I believe the lower rates in the summer months are only available in coastal areas. We do not get our electricity from CFE here in Cuernavaca, but from Luz y Fuerza. Many people do not know that there are two electric companies in México. L y F only serves an area of about 1% of the total land area, but it serves 25% of the national population.


To learn more about L y F click on this link http://www.lfc.gob.mx/ Click on the English button to learn more about the areas served.


CFE and L y F are both government owned utilities and have many faults. In only one way is L y F superior. L y F will not disconnect your electricity if you are late in paying your bill. A neighbor had told us several years ago that they will never turn your electric service off for late payment. About 5 years ago their offices were closed over a month for the Christmas Holidays. I couldn't pay our bill until they reopened their office. I was a month late in paying them.


This year I had to make a trip NOB in February to attend a funeral. My wife stayed here. I knew our electric bill was due to arrive that month and I told my wife to be sure to pay it. I also called her from California to remind her to pay it. When I got home, I found that she had forgotten to pay it. We went to the L y F office the next day to pay it 7 days late. Nothing was said about being late paying, and no extra charges were levied, no late fees, nothing.


When we lived in the southern area of Cuernavaca served by CFE ten years ago, CFE disconnected our power on the day the bill was due one time. I came home from paying the electric bill to find that we had no electricity. CFE disconnected the wire at the top of the power pole. Fortunately, a neighbors gardener knew how to reconnect us. He used a ladder to get to the top of the pole to do it. CFE told us they would send a man out the next day to reconnect us.


It was over two weeks before CFE sent a lineman to make the reconnection. When the lineman found that our house was already connected, he just rang the bell and asked me if everything was OK? I played dumb, and told him everything was fine. I think the lineman was probably happy that he didn't need to climb the pole and work with the high voltage wiring up there.


Rex
"The supreme happiness of life is the conviction that we are loved" - Victor Hugo


DanGair

Sep 14, 2009, 6:26 AM

Post #16 of 18 (8166 views)

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Re: [johanson] Solar Supplies and Grid Tie Info

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http://www.cfe.gob.mx/es/informacionalcliente/conocetutarifa

Please take a look at this. It was confusing to me at first. Now it makes sense. Sure, it took several hours of study or experimenting around clicking on the various links at the above URL. But now it makes sense. And it will do for you too. You just need to spend a little time studying the above URL, you know, the above link.


OK. I've studied the link and am bamboozled and need help understanding one point: The rate charts for all but Tarifa 1 are separated into two sections: "temporada de verano" and "temporada fuera de verano, however both sections of the chart, summer and non-summer, show varying rates for all months. In other words; rates for December show up in the summer months part, and rates for June show up in the non-summer part, and visa versa. How can July (or any other month) show up in both the summer and non-summer charts, and at different rates? I know I'm probably just being dense, but...
MexDog


DanGair

Sep 14, 2009, 10:06 AM

Post #17 of 18 (8146 views)

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Re: [johanson] Solar Supplies and Grid Tie Info

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Looking for an investment with the potential to earn more than 10% annually??? This thread got me thinking, and I’ve concluded that it is possible to do just that!

According to my math, if you are a DAC power user consuming 1000+KW a month, then you are paying at least $3000/yr (3 pesos/kw or $.25 x 1000kw x 12mo’s). If, instead, you invested in a solar photovoltaic system to produce the electricity yourself, you would have the potential to earn back your investment and even make a tidy profit.

Here’s what I’m thinking:

A grid tied solar system large enough to cover 1000kw/month usage would cost roughly $56,000 US (7kw system x 5 peak sun hours per day *(see note at bottom) = 35kw per day or 1,050 kw/month, then multiply that by an average installed price of $8kw (current US prices) and the system price would be: $56,000.)

Now dividing the $3,000 per year utility bill into $56,000 system cost means that the expected payback period would be: 18.66 years. Assuming that one will be in the same house for the entire period, or that the value of the house if sold would increase by a comparable amount, the investment would not have gained anything (other than the feel good of having done your part to combat global warming), but wouldn’t have lost ground either (other than the potential for having made more on your money somewhere else).

Now, if one starts looking at other issues, such as the fact that the Mexico’s most important Cantarell oil field peaked production in 2004 and is now in rapid decline, then the notion that electric rates will climb in coming years makes locking in the .25 price by creating your own power start to look more attractive. If the rate charged for electric were to increase at 5% a year say, then, by my calculations using the above numbers, your system would be paid for in 13 years rather than 18. Still no growth in your investment though, just a quicker payback, right? Well, not necessarily. If you start looking at the fact that at that point, year 13, without having installed solar, you would be paying more than $5,000 annual for your electricity, and with the rates still climbing, the investment in solar begins looking better and better. By my calculations for this scenario, at year 13 you’ve achieved payback and your investment would now start yielding a solid 10% annual return, with that rate continually increasing over time as the rates increase further! If you follow Peak Oil theorists and believe, as I happen to, that energy rates may very well skyrocket rather than merely climb, then the return on your solar investment has the potential to skyrocket with them. Personally, I don’t know of any investments out there with this kind of upside potential with such little downside risk.

Of course these are very rough numbers and are based on unknowable variables such as future costs for electric, system maintenance issues, and your own plans for residing in or willing your property. However, as I look toward the future, investing in the production of my wife’s and my electricity through our retirement years in Mexico starts looking like a fairly reasonable bet to make!

Your thoughts?

* note: Regarding peak sun: Johanson, in your post you said you are producing up to 12kw/day with ten panels. The largest commercially available panels I know of are rated for 200 (205) watt’s per panel. This would mean that for your ten panels to produce 1200kw/day, you are seeing 6 peak sun hours on those days, or even more than 6 if your panels are actually smaller, say 175watt. Those numbers are quite high, but certainly not implausible. For the above calculations I am using a more conservative multiplier of 5 peak hours/day. Some solar irradiation charts have parts of mexico listed as closer to 4 peak hours though. The lower the peak hours, the larger system one would have to have to hit the above targets, which would in turn extend out one’s payback period.
MexDog


delmaracer

Sep 29, 2009, 10:09 PM

Post #18 of 18 (8022 views)

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Re: [rockydog85251] Solar Supplies and Grid Tie Info

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Over here in BC, we get a summer subsidy of 17%.
Bob
 
 
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