Inverter/ Grid-Tie inverter Technology-pricing

Thomas

Any one have any information about what is the story with inverter prices/technology and international availability and consistancy w/ the markets? What is the story with Chinese inverters and the computer power cord? I think it is a import/export/ for sale ... thing....

BB.

Re: Inverter/ Grid-Tie inverter Technology-pricing

I don't which brand/model of Chinese GT inverter you have--But the generic plug-in models we have seen so far lack UL/NRTL Listing, are unreliable, over heat at >50% of rated capacity, and cannot "safely" be connected per their instructions.

Before you joined, we had one guy here that worked for a plug in GT inverter company and he spent a month or so telling us UL/NRTL was just around the corner (factory info). However--that "just around the corner" came and went.

Will your "blow up"--Probably not, and you probably will not do stupid stuff like plug in too many loads on the GT inverter circuit or let a bunny chew the power cord (my kids' pet problem).

The best "small inverter" are the Enphase (~200 watt @ 240 VAC) and others that are UL/NRTL approved and hardwired to the branch circuit (of course, there is nothing stopping you from attaching a plug to the Enphase cabling either). I think there may be some newer 120 VAC micro inverters out there--But I don't follow the industry, so I am not sure where to purchase those. Add the base station that is needed to communicate and display the power information from each module/solar panel--Again another hit against small installs if you want "full" monitoring.

The central inverters are less expensive ($$$/Watt) the larger they go. A 700 watt GT inverter from SMA is not going to be cheap or cost effective. Add cost for permits and a licensed electrician (usually required)--A 700 watt GT solar array is just too expensive for most applications.

-Bill

Thomas

Re: Inverter/ Grid-Tie inverter Technology-pricing

Do they really pose a safety concern, I could see if the inverters were really powered up, like transformers, now theres danger. I maen if you plug it up wrong, it just does not work any more, no fire, no sparks, I have incorectly used them in the past, American Inverters and the Chinese ones, the only real negative is a waste of time and money,When I fisrst heard of inverters I was sceptical. Now I know grid tie work but have concerns about off grid inverting. I plan to continue with grid tie, one month at a time.

solarvic

Re: Inverter/ Grid-Tie inverter Technology-pricing

I did have a post but deleted it. Too many different post scattered around with the same topic.

icarus

Re: Inverter/ Grid-Tie inverter Technology-pricing

The answer to your question "do they really pose a safety hazzard?" The answer is,, because they are not publicly tested, their failure rates and points are unknown. They may be well built, and safe, but IMHO the chances that they are not so well built, and ergo not real safe is more likely,, or they would pursue UL listing.

A proper (UL listed) Enphase 190 watt inverter is ~ $227 from our site sponsor.
There is a reason that real, UL listed products cost more. They are tested and that testing costs money. They are also liable for damage caused by failures. You think your non UL listed products will step up if your house burns down as a result of a failure? I would doubt it.

Icarus

PS On an interesting side note, I recently had a fire event with a breaker protected 4 gang extension cord box. It was out door installation, and when turned on with an LED X-mas light string, the box started arcing and burst into flame. The breaker on the outlet didn't trip, the branch circuit breaker didn't trip. If I hadn't been there, the results could have/would have been disasterous! Taking it apart revealed that small insects or pieces leaves had gotten in the box, causing the short, and the fuel for the fire.

While this doesn't really relate to your situation, it is what you cannot anticipate that will kill you. The point of testing is that a product, when used as designed will not present an undue safety issue,, and if it does, it gets recalled. (My box in question was not approved for continuous outdoor use, so it was not used as designed,, my bad!)

Thomas

Re: Inverter/ Grid-Tie inverter Technology-pricing

I agree that the unexpexcted is the rule esp. these days with the weather the way it is, man I get 30-40 deg spreads weeklt ony changes by like 10 deg max. If any one can figure things like this into public continuity it would probobly be UL. I built my wind ginny with there specs, the only real difference was gronding and an access box @ the end of the generators output cables. Can't say I understood that then, I have used it a dozen or so times ....
does the enphase have a lvd point? I am trying to use batteries for night time use.. the one I have now works with both. Good so far. I shopped around a while to find an inverter that accepted 12v batt voltages and dual function w/batteries. Most do not. If the inverter charges batteries at all it is from the grid, not from pv/wind. Chinese e-bay used to have some dual chargers/inverter combos I cant find anymore. Blue sky nonmeclature is the only charger that accomodates for both the different inverter load/draw and battery charging requirements in the morning. I dont think the enphase work at all with batteries after dark. Is it possible to spin enough backwards to financially make it to dawn..??

GreenerPower

Re: Inverter/ Grid-Tie inverter Technology-pricing

icarus wrote: »

The answer to your question "do they really pose a safety hazzard?" The answer is,, because they are not publicly tested, their failure rates and points are unknown. They may be well built, and safe, but IMHO the chances that they are not so well built, and ergo not real safe is more likely,, or they would pursue UL listing.

Search youtube for "Power Jack 300 and SUN 250 Grid Tie Inverter REPAIR", comments from various owners :

"Most of these GTIs fail by a MOSFET shorting out and either blowing the DC fuse or the AC fuse. The repair procedure is similar. This video shows how to reinstall a coil that fell off, as well as how to replace the AC fuse and one of the MOSFETS on the AC side of the GTI."

... and on "PowerJack 600W Grid Tie Inverter Bad?"

"wow! not surprised i have bought several of these units various sizes and have had a 60% fail rate.once you contact the seller on ebay they may at best replace the unit but they certainly will block you from bidding on any more of there inverters. I have at least 10 of these things laying around useless that they will not make good.I find it interesting that they sell replacement parts as well on ebay as though they know these are another chinese disposable junk product "

Enough said.

GP

Thomas

Re: Inverter/ Grid-Tie inverter Technology-pricing

I just need this to last untill $$$$$$$$$$$$$$/tttttttttttttttttttttttime.....and am saving, though a new grid tie is not THE priority, a byclcle is,
I have a few foriegn chargers around, I can and did afford a Name Brand....up date @ 30A waypoint of my solar...ing.

jagec

Re: Inverter/ Grid-Tie inverter Technology-pricing

Thomas wrote: »

I agree that the unexpexcted is the rule esp. these days with the weather the way it is, man I get 30-40 deg spreads weeklt ony changes by like 10 deg max. If any one can figure things like this into public continuity it would probobly be UL. I built my wind ginny with there specs, the only real difference was gronding and an access box @ the end of the generators output cables. Can't say I understood that then, I have used it a dozen or so times ....
does the enphase have a lvd point? I am trying to use batteries for night time use.. the one I have now works with both. Good so far. I shopped around a while to find an inverter that accepted 12v batt voltages and dual function w/batteries. Most do not. If the inverter charges batteries at all it is from the grid, not from pv/wind. Chinese e-bay used to have some dual chargers/inverter combos I cant find anymore. Blue sky nonmeclature is the only charger that accomodates for both the different inverter load/draw and battery charging requirements in the morning. I dont think the enphase work at all with batteries after dark. Is it possible to spin enough backwards to financially make it to dawn..??

Financially, grid tied solar makes a lot more sense than off-grid *assuming that you're already connected to the grid*, but whether it would beat other investments depends heavily on your local regulatory climate. I've got a SREC market that I can sell into, which is essentially the only reason that solar made financial sense for me.

And yes, most days I DO make enough power during the day to pay for what I use during the night. And since billing is only once a month, I have yet to pay for power, and probably won't until July or August when my AC loads will exceed my generation capacity.

Thomas

Re: Inverter/ Grid-Tie inverter Technology-pricing

How is Quality of life switching back and forth power supplies daily?Nightly? Headaches? Nausea? Thank you.
My bill is down some , it has been for the 6 months I have installed solar, at least the consumption is, I am on a levelized billing program, pay more in winter ,less in summer, it is just the same, if I keep investing in solar, maybee the whole average will continue to go down. thanks again for the feedback

jagec

Re: Inverter/ Grid-Tie inverter Technology-pricing

Thomas wrote: »

How is Quality of life switching back and forth power supplies daily?Nightly? Headaches? Nausea? Thank you.
My bill is down some , it has been for the 6 months I have installed solar, at least the consumption is, I am on a levelized billing program, pay more in winter ,less in summer, it is just the same, if I keep investing in solar, maybee the whole average will continue to go down. thanks again for the feedback

There is no switching, the grid-tied inverter just pumps juice onto the grid (spinning the meter backwards) when I'm producing more than I'm using. At night the meter spins forwards again. Over the course of the year, I'll produce about as much as I use, so I'll probably end up barely ever paying for electricity.

I have an energy monitoring system so that I can see how much I'm producing and consuming in real-time, or historically.

Thomas

Re: Inverter/ Grid-Tie inverter Technology-pricing

when the meter is back to spinning the other way , after the GTI is done, isn't that switched back to the grid ?

solarvic

Re: Inverter/ Grid-Tie inverter Technology-pricing

Its always on the grid 24/7. If you aren,t generating what you need such as a cloudy day the grid furnishes the remainder power needed. On bright sunny days you should be generating much more than you use. Thus accumulating for night time and low power generating days. Jageg,s system is big enough that he averages enough power to not to need to pay for any power from the grid. I also have a big enough gti setup that I havn,t had to buy any power from the power co since last Jan 2011. I got rid of the electric dryer, ,installed a ge geospring waterheater and a space heater and got more efficient with my home. :-)solarvic:cool:

Thomas

Re: Inverter/ Grid-Tie inverter Technology-pricing

Thats my goal, during the day I think I make about 20% more than I use, I won't look at the meter though, Voodoo here....

BB.

Re: Inverter/ Grid-Tie inverter Technology-pricing

No "switching involved"... Just like DC power system in a car. The battery supplies power to the lights/stuff, start the engine, the alternator recharges the battery bank. At the end of the trip, the engine shuts down and the battery again supplies power to the radio/lights/etc.

"The Grid" is just like a giant AC Battery. The GT Inverter is very much like the Alternator (DC rectified) from the car.

-Bill

solar_dave

Re: Inverter/ Grid-Tie inverter Technology-pricing

BB. wrote: »

No "switching involved"... Just like DC power system in a car. The battery supplies power to the lights/stuff, start the engine, the alternator recharges the battery bank. At the end of the trip, the engine shuts down and the battery again supplies power to the radio/lights/etc.

"The Grid" is just like a giant AC Battery. The GT Inverter is very much like the Alternator (DC rectified) from the car.

-This is wher the Voodoo of having a correct type meter installed to spin backwards and an interconnect agreement with the utility comes into play.

Thomas

Re: Inverter/ Grid-Tie inverter Technology-pricing

No scammin really about the meter, it has got more to do with my 'midas touch' problem...watched pot never boils. Case in point my solar hot water panels, as soon as I do anything to them like adjust the rate of water flow thru them, the whole thing reduces like 30% or something...untill a few days after I do not fool with my last pump speed..can I see the results of the last adjustment.
as for the meter I do not even want to lay eyes on it and all of the technicals that would follow, my bill reflects conservative savings, good enough for now to me...