25 kw solar system - electricity usage went up

texassol

I live in South Texas and the ranch I am on has had a large solar system installed. The company that installed it was in way over their head. Although they seem to have used good components, the system is in no way operating as the purchasers intended (I am a close friend and on the array as well.) There is a large abc switch that is supposed to switch us from on the grid completely to off the grid completely. It turns out that we are never really off the grid and seem to use more electricity when "off the grid." The system was supposed to be large enough to be grid independent but the more I research it seems that they did the opposite. They are clueless and try and assure us that everything is normal. Well, using 31 kwhrs per day "off the grid" vs 19 kwhrs "on the grid" is not normal. That seems to be the trend when we take meter readings and switch back and forth on the abc switch. I suspect that the batteries are being charged by the grid and then converted to ac to power our houses thus losing efficiency through the inverters. The desire of the system is to be *completely* off the grid when switched and still have the ability to switch back on the grid if wanted. It may turn out that we will have to hire someone to come in and straighten this out and fight the company for reimbursement. Here are the details of the two systems (there are more, but I won't even go there now.)

System 1 - 15kw Running a 3 bedroom home

72 Centennial Solar CS-200 panels (about 200 peak watts each I think)

1 Kw Wind turbine with P1000c-A/1 wind controller

3 xantrex xw 6048-120/240-60 hybrid inverter/chargers

3 Apollo Mppt turbo charger battery controllers

4 Hawker energy plus batteries. Looks like the one pictured here: http://www.hawkerpowersource.com/products/energy_plus.htm
The inverter says when fully charged the battery has over a 1000 amp hours remaining. BTW the original bid says Non energy plus batteries. Maybe typo?

System 2 - 10 kw running a smaller 3 bedroom house


48 Centennial Solar CS-200 panels (about 230 peak watts each I think)

2 xantrex xw 6048-120/240-60 hybrid inverter/chargers

2 Apollo Mppt turbo charger battery controllers

1 Hawker energy plus batteries. Don't understand if the company listed 4 batteries on system one, then why system 2 list one, but is only half the size (you would think it would be 4 times as small.) Again they are clueless and can't even answer simple question. Inverter says 600 amp hours remaining when fully charged.

With my very limited knowledge I think that the system's framework is in place properly for a backup system but needs to be reconfigured differently to match what the original design was supposed to be for - an off the grid system with the ability to switch back on the grid. They claim we need the grid power to run the inverters and there is no way to power them from the array and battery. They also failed to tell us that the batteries are being charged from the grid and tried to finalize the year and a half overdue project by saying "you are completely off the grid now." What? did they think we weren't going to see our electric bill mysteriously go up?

Any advice on the direction we need to go to make this system independent of the grid would be appreciated. Can it be configured that way or does it have to have to have the grid to power the inverters?

Thanks!

Cariboocoot

Re: 25 kw solar system - electricity usage went up

The first thing I noticed about the system is the Xantrex hybrid inverters. These are meant to be grid-tie; back-feeding the grid any surplus power from the panels and providing battery-based power if the grid goes down. In that respect it's quite a good idea, but there wouldn't be any "A-B-C" switch, as the inverters would handle that automatically.

How are you measuring your power usage? It makes a difference where the Watts are being metered and how. If it was set-up right, the meter should run quite slowly or even "backwards" as the solar provides most of the energy needs. The grid would supply only at night or if demand outstripped production. The grid should not be recharging the batteries. If it is, then the Xantrex is programmed wrong.

Considering the size and complexity of it, the possible number of wiring mistakes that could have been made are mind-boggling. And potentially dangerous in some cases.

I think this is a case of "find someone in the area who really does know what they're doing and get them to check every last bit", if only because you are not satisfied with the performance and explanations given by the original company.

Trying to analyze and correct this via the forum could take months, even with the experts here, due to not being able to "see" all the wiring and connections.

BB.

Re: 25 kw solar system - electricity usage went up

One possibility--The Xantrex XW is, more or less, like a giant UPS (Uninterruptible Power Supply) system for your home. The batteries are "charged" by the solar array during normal operation.

The intent behind the XW is that all of your "protected loads" hang off the "output" side of the inverter behind an internal automatic AC transfer switch (the other connection, I believe, for the transfer switch would be to a Genset for backup AC power). This is an A-B-C switch of sorts...

Now, in off grid mode, only items connected to the protected "output" of the XW inverter will be powered directly from the solar panels / battery bank / backup genset.

In Grid Tied mode, the protected loads are connected directly to the utility for power, and the Inverter operated in "Grid Tie" or "Utility Interactive" Mode to simply add its power to the home's electrical wiring... (just like the alternator supplies power to the car electrics and also charging the battery bank).

There are several ways that you could still consume power from the grid when in "off grid" mode.

The first would be that some of your large loads are connected not to the inverters protected output, but simply to your main utility panel. These guys use utility power 100% of the time, and are not supplied by battery/Off Grid inverter power.

For saving money (running with solar panels)--this still works very well--When you have utility power, the GT inverter mode simply puts power in to your home's wiring... The power is either used to power the loads and/or turn the meter backwards (when you have more solar power available than loads).

When you go off grid, these guys are still being powered by the utility and the XW inverter is now in Off Grid mode and unable to pump power back through the rest of your wiring and running the utility connected loads (and unable to turn the meter backwards).

The second possibility... There are two inputs on the Xantrex XW inverter... AC1 and AC2 (I think that is how they are labeled--I don't have an XW system and I am not an installer)... AC1 is intended to connect to the Utility power and AC2 to the genset... If the utility power was connected to the AC2 input--the system would be still using utility power to run the loads/charge the battery bank--But it would not be able to pump power back into the meter (i.e., your extra solar power during the day is wasted; not enough load and batteries are full)...

Anyway--pending further information--those are my guesses.

-Bill

Cariboocoot

Re: 25 kw solar system - electricity usage went up

For instance, if we knew what the loads were it would be possible to determine if there was enough inverter to handle them. In one case you've got 12 kW, and the other 18 kW. That sounds like a lot unless you're trying to run electric stoves, hot water, heat/AC. I think one of the ways the Xantrex can be configured is to pull power from AC2 (or 1?) to make up for lack of capacity from the batteries.

And if it's grid-tie and they didn't do it right (i.e. co-ordinate with the utility) the actual meter may not be capable of reading "backwards", and your production sold to the grid would appear as further consumption!

There's just so many ways this could be wired wrong, and so few that could be right.

texassol

Re: 25 kw solar system - electricity usage went up

I didn't make it clear in my post but my main goal on the forum was to get an idea if we had the right equipment for a completely off the grid system that could be switched on the grid if necessary. The original idea was to sell excess back to the utility company, but apparently they do not have that software yet, so the best we can hope for at this point is just to become completely energy independent (ideally with out any juice from utility unless desired.) So the main question is: If we were to hire a knowledgeable person or company could they accomplish our goal using mostly existing equipment. Also, if anyone has recommendations of a person or company in the South Texas/Kerrville area that knows what the heck their doing, that would be great too. At this point I haven't touched it because of the obvious problems that would create when trying to make a company stand good on their installation.

Also, we are getting the meter readings directly from the utility companies meters. The usage definitely goes UP when we are switched to the array vs the grid. Something is very wrong.

Thanks so much for the replies. Things are getting clearer and clearer.

Cariboocoot

Re: 25 kw solar system - electricity usage went up

So it will come down to what sort of loads you need to supply.

Very rough estimates:
System 1 should be capable of about 30 kW hours per day.
System 2 should be capable of about 20 kW hours per day.

I'm sure Bill will be kind enough to run the PV Watts program for your data and come up with some more realistic numbers (it doesn't work on my Linux netbook!)

Given that amount of available power, what does it have to run? That's the important bit.

Sure sounds like they did a grid-tie and the meter is counting up for the excess power you produce.

I wouldn't put too much thought in the wind turbine. Most of the time there really isn't enough wind available to get any significant contribution from them.

BTW, for us die-hard off-gridders 20 kW hours per day is about 10 times what we use!

Cariboocoot

Re: 25 kw solar system - electricity usage went up

P.S.:

Also need some specs on the batteries. Does System 1 have Four 1000 Amp hour 48 Volt and System 2 One 1000 Amp hour 48 Volt? Just trying to get a handle on the panel-to-battery ratio.

texassol

Re: 25 kw solar system - electricity usage went up

I attached pictures of both batteries. The smaller one has this on the label on the side. It also has a lid on other side that the battery extends under.

6hr capacity - 600 A.H.
Nominal voltage 48
???? rate - 30 amps. Not sure what it says

The larger battery has 0's in those fields.

I think the larger battery is capable of 1000 A.H. but not positive about that. On the diagnostic screen of the controller it says 1000 amp hours remaining when battery is fully charged.

I think the system is plenty for us to run comfortably on. If not we will adjust until it is.

Cariboocoot

Re: 25 kw solar system - electricity usage went up

I have to say that my netbook has a 7" screen and my eyes are old. I can't make out those pictures very well. From what it looks like to me, it doesn't make any sense at all. Both images seem to show all cells wired in series, which would make the smaller one 24 V (won't run a 48 V inverter) unless they are 4 V cells. But that would make the larger one 96 V, which also doesn't make sense. The answer can only be that I can't make them out right.

Or disconnect the wires and check the Voltage with a DVM. Can't find any specs on the batteries from that linked page, either. These seem to be forklift-type, which is fine - unless they're wrong Voltage/Amperage.

Solar Guppy

Re: 25 kw solar system - electricity usage went up

If your intent is to be 100% off-grid, you need to know what your loads are. Your system while large, isn't going to power a typical suburban house 24/7.

The some of the Equipment is the best you can get, the Xantrex 6048's are best in class, the battery are good, though you probably need 4X more to be 100% off gird.

On thing you can do, is run the system as is, but just disable the sell mode ( your selling is causing your increased bills as that's a theft protection feature ) , assuming you have the Xantrex SCP's, is an option under the main menu to disable the sell and you can configure the XW-6048 chargers to only come on at low battery conditions, allowing you to use the solar as much as possible.

Most of what you have is good stuff, just need a good installer who deals with off-grid system to make some adjustments and possibly changes depending on your budget

BB.

Re: 25 kw solar system - electricity usage went up

Solar Guppy wrote: »

On thing you can do, is run the system as is, but just disable the sell mode ( your selling is causing your increased bills as that's a theft protection feature ) , assuming you have the Xantrex SCP's, is an option under the main menu to disable the sell and you can configure the XW-6048 chargers to only come on at low battery conditions, allowing you to use the solar as much as possible.

Pay close attention to what SG typed... You are paying the utility company retail for the privilege of giving them free power. Your meter will count up (charge you) if you use a 100kWH of power from the grid or if you generate 100kWH of power into the grid...

Disabling "Sell Mode" (not exporting any more power to the grid) may save you a lot of money.

-Bill

texassol

Re: 25 kw solar system - electricity usage went up

I am in the process of figuring out where to change the setting. Thanks

Solar Guppy

Re: 25 kw solar system - electricity usage went up

Here is a quick step by step to turn off sell mode

You really need to ready the manual front to back on the XW-6048

Also, if you have the grid connected, you won't be using the solar for the loads, the XW-6048 will just pass thru , again this is all discussed in detail in the manual

I think you will find, with a few hours reading and a few questions answered, you will know more than most installers on how to properly configure your system, it may seem over whelming at first, but the XW-6048 is a great inverter is has more options than any other on the market, so its just a matter if setting it up to work how you want

texassol

Re: 25 kw solar system - electricity usage went up

Thanks for the great step by step. I found a copy of the manual online and am beginning to read it. However, I do not find a controller for the xantrex anywhere! If it is detachable or wireless they must have it. All I have on the Xantrex is the inverter info panel with power button and battery equalize button. Unless I am missing it somewhere beneath a panel I will need to check with the install company to see if they have it or even ordered it.

Solar Guppy

Re: 25 kw solar system - electricity usage went up

Not surprised, either the installers had one or worse, its just running in its default configuration

http://store.solar-electric.com/xaxwsycopas.html

Buy this, all it uses is a standard CAT5 cable to connect to the inverter ( bottom right is where it plugs in )

With a system of your size its a MUST have, you probably need one of each system.

Are the XW-6048's interconnected? or are they running independent with separate loads? ( each house's units , not inter-house )

texassol

Re: 25 kw solar system - electricity usage went up

Finally got a hold of the installer. They do have the control panel and will come out Friday with electric company. I did witness the meter going backwards yesterday during a sunny period. When a cloud came over it began running forward fairly fast. It even ran backwards when the solar was supposed to be disconnected via abc switch. Something is very wrong and not just in the programming. Will give them a final chance to get straightened out and will recommend hiring someone knowledgeable. Will post an update after they come out.

texassol

Re: 25 kw solar system - electricity usage went up

I am fixing to order the system control panel from this site and I wondering if anyone could tell me if the control panel comes with the cat 5 cable?

Cariboocoot

Re: 25 kw solar system - electricity usage went up

texassol wrote: »

I am fixing to order the system control panel from this site and I wondering if anyone could tell me if the control panel comes with the cat 5 cable?

Call NAWS and ask them. Can't beat going straight to the source for the answer.

I'm still wondering where your "genius" :roll: installers wired that transfer switch in!

texassol

Re: 25 kw solar system - electricity usage went up

I did get a hold of them and it does come with it. Ordered 2.

Who knows about the transfer switch. Maybe it is a dummy switch.

tr0y

Re: 25 kw solar system - electricity usage went up

Hi SG and other experts -

I know this is an old thread, and I am not trying to hijack it , but your quote as this system is not big enough for suburban 24/7 puzzles me. I know your are an industry expert but if I had a system like this I could live like a king I think I would go to electric water heaters.

I don't have half this gear and two of us, live in a 3500 sqft home with normal TVs, computers, fridge, heater etc and seem to do just fine, I highly doubt I am doing anything special I am somewhat militant about turning off lights but that is about it.

I do have to fire the generator when it snows or I don't have sun for more than two days, but beyond that I haven't lived on anything but the sun for almost 10 months now. My only extra here is I live at 7000' in southern NV.

When the budget allows I want to double the panels and the battery but even then I doubt I'll be this well set up.

My basic system is 10 Evergreen 205 w Panels, an MX60, an SW5548, and 8 400 AH AGM batteries.

I keep a pretty close eye on it and most days we are in float for 200 to 300 plus minutes, I don't think I am that smart, am I just lucky ?

Thanks

tr0y

BB.

Re: 25 kw solar system - electricity usage went up

In Texas, probably Air Conditioning is a large mount of the load...

Also, may depend what is available/legal/customary in the OP's area for Propane, Natural Gas, or other heating fuel sources (stove, hot water, drier, space heating).

For myself, I am running a bit over 300 kWH per month (I have increased with a freezer, extra small fridge, kids now old enough for computers, etc.) and less following around everyone turning off the lights--from my summer low of ~170 kWH per month.

Our 3.5 kW array has been more than enough to keep up with our Grid Tied usage over the year...

But things happen--Right now, my 3.5 kW array is "in the shop" waiting for a replacement set for another 2 months (3+ months?)...

Large systems "scare me" because there are things that can still go wrong/need replacement over time. Being your own power station with solar RE (or other power sources) is not cheap.

-Bill

Solar Guppy

Re: 25 kw solar system - electricity usage went up

The OP is in south Texas and he has two systems, not one, powering a pair of larger AC cooled homes. AC, all by themselves in a hot climate can easily exceed the power a properly operating 25K PV solar can generate. In my neighborhood, the monthly power usage is 3000-4000 kWhr as an average, I know some one that exceeds this with a two story home 1/2 mile away, Old SEER 8 AC's with little insulation in the attic.

Your home at 7K feet has no AC load and while you leave out the details, I can tell your not heating with electric buy your usage.

It's all about the loads, not luck. Your system sounds small it you run out of power in 2 days, but quite workable with generator usage as necessary. You also benefit from lower than average cloud cover, which help in your favor

tr0y

Re: 25 kw solar system - electricity usage went up

As I figured, the pros would have an answer, I do forget about AC loads and old leaky houses. Our system is a bit small but the house build had to be the driver in the solar budget, as we have funds the solar system will get bigger. The local utility wanted 19 Million to run power to the community, 60 houses, and most are part time residents so it wasn't going to really work out. So Solar, if you can call it this is the "cheap" way for power.

In the summer we do run an evaporative cooler and it works great here as there is no humidity at all, some times as low as 3% .

We do use propane for hot water, laundry, range and furnace, but also have a very large wood stove.

It just seemed like a lot of power as even when we lived in the desert we were very power aware with the AC ( proper factoring for unit size and ducting to extract maximum efficiency and 19 seer unit) and built very efficient well insulated structures.

Thanks again I do learn a ton from all of the brains here. I read quite abit more than I post, so your wisdom does not go unnoticed.

Thanks !

BB.

Re: 25 kw solar system - electricity usage went up

Tr0y,

If you wished, I am sure that people would be very interested To read a thread about how to design a home for a cold climate and how much solar and alternative fuels a real family uses.

I like real examples that people can review when thinking about joining the off grid lifestyle.

-Bill

tr0y

Re: 25 kw solar system - electricity usage went up

Hi Bill -

I am starting a new job tomorrow but when I have a bit I'll write it up from an on the grid existence to 100 MPH in to solarville. This is a bit OT but on my system if I am still in float, per the MX60, for 75 to 120 minutes a day even at this time of year I am assuming I am shy on batteries ?

Thanks

Troy

bmet

Re: 25 kw solar system - electricity usage went up

In the early 1990s I lived in Tucson, and right outside the gate of Davis-Monthan AFB was a large undeveloped acreage that had been proposed to become a solar community. It was prematurely designated 'Solar One'.

Since this is a forum hosted by an Arizona solar vendor, I wonder if anyone could shed some light on what happened to Solar One . Was it killed outright by politics, did it get shelved, was it rolled over into another project, or what???

Seemed like a good idea, but like the Arizona Canal Project, the infrastructure had many casualties. How much of the Colorado River water is lost to evaporation on its 1,000 mile journey to Tucson? How many wild animals die in the desert trying to get to the water, only to be trapped or hung up on the fences?
For a time Tucson backed away from canal water because the water ruined plumbing and killed aquariums. I've been away too long to keep up with it.

Sorry, all this solar discussion reminded of Tucson and I sometimes wish I still resided there.

solar_dave

Re: 25 kw solar system - electricity usage went up

bmet wrote: »

In the early 1990s I lived in Tucson, and right outside the gate of Davis-Monthan AFB was a large undeveloped acreage that had been proposed to become a solar community. It was prematurely designated 'Solar One'.

Since this is a forum hosted by an Arizona solar vendor, I wonder if anyone could shed some light on what happened to Solar One . Was it killed outright by politics, did it get shelved, was it rolled over into another project, or what???

Seemed like a good idea, but like the Arizona Canal Project, the infrastructure had many casualties. How much of the Colorado River water is lost to evaporation on its 1,000 mile journey to Tucson? How many wild animals die in the desert trying to get to the water, only to be trapped or hung up on the fences?
For a time Tucson backed away from canal water because the water ruined plumbing and killed aquariums. I've been away too long to keep up with it.

Sorry, all this solar discussion reminded of Tucson and I sometimes wish I still resided there.

http://www.dm.af.mil/news/story.asp?id=123178279

I think they are there.

ggunn

Re: 25 kw solar system - electricity usage went up

texassol wrote: »

I live in South Texas and the ranch I am on has had a large solar system installed. The company that installed it was in way over their head.

These systems wouldn't be located on a ranch 10 miles or so southwest of Fredericksburg, would they? Ranch owner named Maggie? If not, I know of an eerily similar situation. Same area, same gear, same debacle.

BB.

Re: 25 kw solar system - electricity usage went up

Texasol has not been back since September 26th, 2010...

You might try contacting him/her via PM if you need to talk with them.

If anyone wants to keep any of the off-thread discussions going--I can move them to their own thread.

-Bill

Peter_V

Re: 25 kw solar system - electricity usage went up

BB. wrote: »

Tr0y,

If you wished, I am sure that people would be very interested To read a thread about how to design a home for a cold climate and how much solar and alternative fuels a real family uses.

I like real examples that people can review when thinking about joining the off grid lifestyle.

-Bill

Ok here's another data point.

We live in the high desert in southern Arizona, 4600' elevation. Temp swings from lows around freezing in the winter to highs around 100 (107 is the record) for a couple weeks to a month in the summer.

Really low humidity here so we use a high efficiency swamp cooler instead of AC.
My wife's niece and her family came to visit back in June. They live in a converted school bus, running the AC on the bus used more power than my entire house.

My array is 3.4kw grid-tied on Zomeworks trackers, this provides more power than we use (we've pushed 500 kwh surplus to the grid in the last 3 months)

Since we're grid tied we don't have the losses associated with charging/discharging batteries. I figure we'd need about 25% more PV if we were off grid for the same power consumption (about 19-20 kwh a day)

We use Enphase inverters so I've been comparing my system's performance with a nearby fixed array.

My trackers provide about a 17-18% improvement during the winter and around 30% during the summer. I figure about 10% of that is because I can do seasonal tilt adjustments and they don't.
The trackers would do a bit better, but some trees shadow my array for about an hour in the morning and a nearby mountain range cuts into my evening light by another hour or so.

Peter_V

Re: 25 kw solar system - electricity usage went up

solar_dave wrote: »

http://www.dm.af.mil/news/story.asp?id=123178279

I think they are there.

Indeed they are. My wife and I were up in Tucson a couple weeks ago and we decided to stop by Davis Monthan, something we haven't done in years.

On the way home we drove past the huge array of solar panels which we'd never seen before.

I didn't count them but it was definitely about 20 acres worth of panels and 45,000 panels sounds about right.

I wonder if they'll have to hire someone just to keep them clean, almost looks like a full time job.