Grid-Tied with Backup - available inverters?

[russ]

Anyone that had solar panels in New Orleans at the time of Katrina had to go to Arkansas to try to retrieve them.

Most people whose posts I read on other forums that are off grid have a generator. It helps greatly in taking care of the battery bank. All consider PV power as expensive power.

When talking about consumption it would be far more interesting if a kWh/day number was provided. Simply saying someone has A/C on PV is like saying one spends little on gas for a Hummer. All depends on how things are used.

The typical home (not overly large or with excessive use) consumes about 30 kWh/day I believe - that is not considering heating.

Most people have no business minding a battery bank - with poor care they may well not even come close to 5 years. With excellent care - maybe the ten year figure.

Best regards,
Russ

[greenHouse]

Russ,

That's a pretty gross exaggeration. Ike went through Houston harder than Katrina went through New Orleans and I have net-friends in Houston whose solar survived Ike just fine.

Also, while 30KWh is the average, anyone putting in solar who hasn't worked to get that number way down is wasting money on solar. The only way I get an accurate fix on what I use is to run off-grid so the numbers don't get muddied with buy and sell and who knows what else. But for the most part, I stick to something close to 15KWh / day and I have all sorts of toys.

The key really is to not just waste electricity like mad. There are 6 computers running in the house right now (this instant), plus with the overcast weather many of the lights are on, and some cable TV boxes, and etc. But if it doesn't have to be on, and doesn't have to consume 120 watts (my computers are all well below average and the high power servers stay off when not needed), it stays off. And my consumption for the day is about 4.5KWh at noon. That's definitely a do-able amount of energy conservation -- the key is just to QUIT WASTING ENERGY.

[greenHouse]

Prove it, show me your calculations. My guess if true they live in a very small home built like a refrigerator and use a 1 ton or less cooling system, and they live on a coop system with extremely high electric rates and monthly service connection charges. No one in their right mind would choose to pay more than $1 per Kwh if there were other options. Which brings me to my point, show all the options. How many Hurricanes does Tx Hill Country experience in the last 100 years?

Whatever are you talking about?

They live in the Loyal Valley where it was $15K just to bring poles to the property. They live on a ridge with fair to middling wind and have a mixed system -- Bergey and solar.

And so what if they have a properly insulated home (they do). Is that some kind of crime?

Energy conservation steps are cheaper, and pay better returns, that installing solar. First, conserve, then install solar, and that's how their system works.

I'm also really unclear on where this $1 / KWh comes from -- even outrageous estimates I've seen before for the cost of solar were nowhere near $1 / KWh, so you've created a whole new level of outrageous.

You toss around $10K for batteries, and 5 year service life like it's some kind of fact, and it just plain isn't. And you ignore that conservation -- not being a hermit, just reducing waste -- is part of the equation and suggest that something is wrong with living in an insulated home. I'm sure you're a smart guy and all that, but I'm not buying what you're selling.

[Sunking]

I'm sure you're a smart guy and all that, but I'm not buying what you're selling.

I am not buying what you are selling either. In your last post you have special circumstances like no commercial power available and having to pay $15K to bring it in. That is part of an evaluation process and has to be taken into consideration. The final decision rest on the user shoulders, not mine or yours. My job or POV is to inform the public of all options available, not just one Green POV. After I do that, then the person chooses and I will build whatever. I do not care what choice the user makes, only that he knows all options, cost, and risk.

[greenHouse]

Dereck,

$15K to bring "commercial power" to a residence in a rural setting is very common. It's part of the standard equation. The days of free power poles to some corner of a piece of property are gone.

But even with that, if your $10K every 5 years were right, that $15K cost would be negated very rapidly. NO ONE with grid power would ever install solar because it would just flat-out cost entirely too much.

Austin Energy has long term purchase agreements with some projects between $0.23 and $0.27 / KWh. The last time they made that offer, there was literally a stampede to get projects accepted. That means that battery-backed systems can't be much more than twice that, which is a far cry from $1 / KWh.

[Sunking]

Dereck,

$15K to bring "commercial power" to a residence in a rural setting is very common. It's part of the standard equation. The days of free power poles to some corner of a piece of property are gone.

you are wrong, dead wrong. Only in remote areas where population density is low is when a POCO will charge you to extend lines to your home. It is called ROI, something you young bucks do not understand yet as they live off other peoples money..

If you live in a city environment, utilities are directly behind or in front of your home. All you pay for is your electrician to dig a trench for underground service, or install an overhead weather head to tether the messenger to the pole at the corner of your property. Only in rural environments where the POCO cannot break even in 5 years will they charge you to extend service. They call it investment economics, something they do not teach in college, you have to learn it on your own with experience. :becky::becky:

But even with that, if your $10K every 5 years were right, that $15K cost would be negated very rapidly. NO ONE with grid power would ever install solar because it would just flat-out cost entirely too much.

Austin is an island in TX. It is the only market in TX that has NET METERING LAWS my friend. Maybe you need to move off the island to the mainland. I think you will find, there is another world out there unless you move to Caliphonie with like minded ideology where they value energy policy that makes the poor and working class pay outrageous energy bills and depend on neighbors to finance and supply supply their basic needs of luxury items.

Again you do not know what you are talking about GREEN HORN and only have 1 solution; the GREEN SOLUTION to offer a client. At minimum initial cost to deliver 1 Kwh per day Stand Alone OFF-GRID Battery is $3000 per Kwh, with $1000 of that in battery cost that has to be replace every 5 years my friend. At a national average consumer price of 12.1 cents per Kwh in 5 years will cost you $220 over five years buying it from the POCO verse $1000 just for the battery cost. Throw in the panels, charge controller, and misc material and you just bought yourself electricity of $3000 / 1825 Kwh = $1.64 per Kwh for the first 5 years verse 12.1 cents from the POCO. What damn fool would make that choice between those two options? NOT ME or MY CLIENTS? Maybe you and your Austin TX friends would, but not mass markets.

IMHO I would take that same $3000 and invest it to double my money in 5 to 7 years. What would you do with it? Waste it on batteries?

[greenHouse]

Well, you've just proven beyond a shadow of a doubt that you haven't a clue what you're talking about in Texas.

I have a client with 8KW in Waco -- net metered, two with 17KW total in Round Rock -- net metered. I haven't a clue what my client in Houston has (he keeps adding on ...) -- net metered. I don't have Austin Energy because I live outside the city limits -- net metered.

I worked on a turbine in Fredericksburg -- net metered. Plus a solar system with 11.7KW northeast of Mason -- net metered. I worked on the sale of a system upgrade in Cedar Park -- net metered. I've tried selling solar throughout Pedernales Electric Co-op territory and they net meter. I think Bluebonnet does as well. I know colleagues in Dallas -- net metered.

Sorry -- don't have contacts in West Texas, they probably do wind out there. I think that just about covers Texas.

Net metering by PUC tariff is negotiated between the REP and the customer, unless the REP is a co-op or municipally owned utility, in which case they can refuse to net meter. In Texas, Green Mountain is the #1 preferred REP for folks wanting net metering and they've yet to turn a client down. They pay 1-for-1 up to a 500KWh per month excess.

And I'm still waiting on the $10K for batteries every five years breakdown. And I like the way you costed an entire system over just five years. You should have amortized it over 2 years, then it would be even more expensive and you could be even more right!

[Sunking]

Well, you've just proven beyond a shadow of a doubt that you haven't a clue what you're talking about in Texas.

I have a client with 8KW in Waco -- net metered,

No it is you who has no clue. TX has no Net Metering Law except Austin. Do you have a clue what that means? It means the POCO is not forced to offer it. It means the POCO has the option to offer it or not at their descretion. Your client is lucky his service provider offers it as an option. Most utilities in TX only offer two options:

1. Pay wholesale prices for excess generation, and charge full retail for power bought.
2. No option ayt all. If you install grid tied any excess is free to the POCO and you get squat.
3. There is a 3rd option which you have ran into, some will offer Net Metering

You need some experience Green Horn

[greenHouse]

This has gotten ridiculous.

Texas had a net metering law that providing for "Banking" in which you put in a KWh and you got to take the KWh out later. That was the old tariff.

The tariff was changed by the PUC so that the DRG owner and the REP negotiated the transaction. This was done in '08. The intention was that the DRG owner could negotiate a better deal, as is the case in some areas where the value of the REC is added to the value of the exported energy. In order to insure that the DRG owner retained that ability, the tariff states that the REC is stripped when the power is exported -- so, I've exported about 2MWh since my meter was swapped, and those RECs belong to me, by law. Since I advertise that my company runs on "100% renewable energy", I don't sell my RECs -- I have to "consume" the green power and can't strip and sell the RECs. Sucks being a green company some times.

The consequence is that some utilities -- notably TXU -- have tried strong-arm tactics with DRG system owners. What's actually happened is that customers with battery-backed systems often just went "off-grid" and TXU lost their free electricity. I exported 665KWh before finally getting a clue (they kept claiming that their billing software was having problems ...) and started managing my exports so that my net exported power was decreased by 95%. I think I reached a low of 110KWh imported in a month with almost no exported power before they sent me what has become their 'standard offer' -- $0.12/KWh (or so) for imported power and $0.06/KWh for exported power.

Now, you can be a Nanny State kind of person and say that the PUC ripped us off when they got rid of the old '01 tariff that provided for "Banking", or you can be a Free Market kind of person and acknowledge that with the power to negotiate, comes the potential to ... uh ... negotiate badly. This is why all my clients are on Green Mountain. Go figure.

Here's a link to the '01 regs --

http://www.puc.state.tx.us/rules/subrules/electric/25.211/25.211.pdf

and here's the "Banking" language --

"Banking. A company operating in ERCOT shall make banking services available to any
customer upon the customer's request. This obligation continues until the ERCOT Independent System Operator begins operating ERCOT as a single control area."

You're free to acknowledge that free-market forces have worked and the ability to negotiate our rates, as well as retain ownership of RECs, has been more beneficial in the long run because it is allowing RE-positive companies such as Green Mountain to prosper while RE-negative companies such as TXU are still dealing with almost going bankrupt. And TXU has a =bad= reputation, despite all their efforts at positive PR.

So.

Old tariff -- "Banking" and no guarantee that the REC stays with the system owner.

New tariff -- Ability to negotiate the rate and the REC stays with the system owner by law.

Old tariff -- I lost my REC, which is worth something around $0.02 / KWh ($20/MWh, I believe, though the market for SRECs fluctuates) and I was limited to retail one-for-one.

New tariff -- I keep my REC, utilities are mandated to have a renewable portfolio, which includes purchasing RECs, and maybe I make out better.

With the Renewable Portfolio Standard in Texas, utilities may either generate their own RECs or ... buy them from folks like me. And, under the old tariff, I didn't get to keep my REC.

As an aside, in states with stricter regulation, SRECs can be worth over $0.20 / KWh. Here's a link to SRECTrade --

http://www.srectrade.com/auctionhistory.php

Remember that when converting from $/MWh (1 REC = 1MWh) to $/KWh you divide by ten and that's the value in pennies.

And here's the other piece of news --

http://www.srectrade.com/blog/srec/srec-markets/texas

Remember -- old tariff, I lost my REC, new tariff I keep my REC.

That's the free market, so put on your big boy panties and deal with it. The proof is in the results -- if you compare new wind and solar projects in '07 to '10 ('08 being in the middle somewhere ...), '10 has seen more new RE projects planted than '07 did. If the new tariff was "bad for business", we'd have seen a decline. No decline, not so bad. Maybe a bit uncomfortable as we went from Nanny State to Free Market, but the Free Market worked, as it always works. In the Nanny State my REC was taken from me, and with the rising value of RECs, that wasn't exactly nice.

[Sunking]

Oh Julie , all I can say is Yawn! Here is the link that will tell TX residence the real deal.
I am done with you b/c you are so GREEN HORN and only have one solution. 20 years from now you might understand.

Note in my link is up to date. Most of the TX energy policy is for commercial and industrial users. There is NO NET METERING LAWS in TX for residential consumers. Anything offered in TX by the utilities to residential consumers is out of the goodness of their hearts sweat heart.

I for one will not complain with some of the lowest energy rates, tax base, highest wages, and opportunity in the country. If you do not like that please move off you island in Austin to a socialist country like California who share your ideas and rely on other folks money and work to support your ideas. I hear California population and economic growth is negative now days and they can use you.

In the mean time I will be in mourning about the death of the Texas Rangers loosing to SFG. :becky: Good night.

[greenHouse]

Dereck,

Okay.

Old Tariff -- if I pay $0.12, my solar is worth ... $0.12

New Tariff -- if I pay $0.12 and can sell my SREC for $0.22, I make $0.22 more than whatever the REP pays me for exported power or I save in avoided costs.

You have to actually read what the PUC has written. Here's the relevant text --

[quote]

[ChrisPSolar]

This has gotten so petty and ridiculous that the original question has been lost

Here's a list of grid-tied battery backup inverters:

Xantrex XW-4024 Inverter, 4000W, Grid Tied, Battery Back-Up, 230V 50Hz - 865-1045
Xantrex XW-4548 Inverter, 4500W, Grid Tied, Battery Back-Up, 120V/240V
Xantrex XW-4548 Inverter, 4500W, Grid Tied, Battery Back-Up, 230V 50Hz
Xantrex XW-6048 Inverter, 6000W, Grid Tied, Battery Back-Up, 230V 50Hz 865-1035

Most dealers are still using the Xantrex label, but you may see the Schneider Electric

Outback is much more expensive:
Outback SmartRE Grid-Tied Battery Backup System, 2500W, 120VAC, 60Hz, NEMA 3R, SRE2500-120-NA
Outback SmartRE Grid-Tied Battery Backup System, 3000W, 120/240VAC, 60Hz,NEMA 3R, SRE3000-120/240-NA
Outback SmartRE Grid-Tied Battery Backup System, 3000W, 120VAC, 60Hz, NEMA 3R, SRE3000-120-NA

Some place you can probably find these:

http://www.spheralsolar.com/

http://www.altestore.com/store/

http://sunelec.com/

There are more but I think these should get the job done. With all the arguing I may have missed it: what size systems are you doing? PM me if you want to talk on the phone about your options and sizing considerations.

[robertjhon143]

I am considering retrofitting my 1982 home with a grid-tied with battery backup solar PV system. I understand that there are a limited number of appropriate hybrid inverters available, but don't know what models they are. At the Xantrax site, I couldn't even figure out which, if any, of there devices were appropriate. From one forum message I ran across, the Xantrax XW6048 has been replaced with a different model, but the writer did not identify the new model number.

I would appreciate anyone pointing me to model numbers (any manufacturer) appropriate for my application. I can then look up the specifications and prices and try to make sense of it all.

Thanks.

I guess your model number would be XW6048-230-50/XW6048E. But Xantrex Engineer can tell your model nuber after looking your inverters.

[greenHouse]

The OutBack would be one of the SmartRE systems or a FLEXpower 2.

The advantage of OutBack over Xantrex is that OutBack gear tends to work, while Xantrex ... not so much. Hopefully Schneider can fix the communications bus problems, but I'm not holding my breath.

[Mike90250]

The OutBack would be one of the SmartRE systems or a FLEXpower 2.

The advantage of OutBack over Xantrex is that OutBack gear tends to work, while Xantrex ... not so much. Hopefully Schneider can fix the communications bus problems, but I'm not holding my breath.

The advantage of Xantrex over OutBack, is that Xantrex has native 240V split phase, and no extra transfromer needed. So if you have any well or sewage pumps that run on 240V, they will still run.
All my Xantrex gear seems to run ok, batteries are my weak link.