Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Off-Grid, Batteries & Inverters => Topic started by: stephendv on May 06, 2014, 10:17:59 AM



Title: Recommendations for 1200W-2000W off-grid inverter
Post by: stephendv on May 06, 2014, 10:17:59 AM
Designing a small off-grid system for a mate and have 3 inverter options to choose from.  They're don't want an inverter/charger, just inverter and must be Pure sine wave.  Loads are:
- 3 x 6W LEDS
- A+++ fridge freezer
- A++ washing machine
- 2 x laptops

Cheapest is 1200W Victron phoenix, IMO the 1200W is maybe a bit tight especially if both the fridge compressor and washing machine happen to come on at the same time.  Advantage is that in 3 years time, if they need more inverter they can get another Victron and have 2400W on tap.

Next up is a Xantrex prosine 1800W for just a bit more dosh than the Victron 1200W.  Don't really know much about these inverters, seem good according to the spec sheet.

Studer AJ1300 is the most pricey, at about 20% more expensive than the victron but it comes with a 5 year warranty.  No option to parallel to in the future, so they'd have to sell it and get something bigger.

Any strong opinions on the choices?



Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: clockmanFR on May 06, 2014, 10:25:16 AM
Can you Hint at prices, about etc.?

Like the concept of "option to parallel to in the future".?


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: stephendv on May 06, 2014, 10:39:26 AM
Can you Hint at prices, about etc.?

Like the concept of "option to parallel to in the future".?

Don't want to step on our host's toes, so the only price I can hit at is the Xantrex prosine 1800W which goes for about 550 Euros + VAT.  The Victron parallel operation comes with a caveat in that you can only connect absolutely identical models.  Have heard of problems where, for example, a 2001 model phoenix 2000W cannot be paralleled with a 2005 model phoenix 2000W.  And of course, the cost of 2 units is more than the cost of a single equivalently specced bigger unit.


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: Iain on May 06, 2014, 10:39:56 AM
Hi
Hasn't Biff got a Symmetra, or some similar spelling!!
I believe they are modular, might be worth a search.

http://www.navitron.org.uk/forum/index.php/topic,13508.msg151416.html#msg151416
Iain


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: oliver90owner on May 06, 2014, 11:59:08 AM
  Not looked up the specs for thoe inverters, but I will ask the obvious questions about power.

Are you sure the washing machine heater power is less than 2kW?

Is the fridge freezer soft start?

The former is the most important, but the total power at a stalled fridge start could be a problem.


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: stephendv on May 06, 2014, 12:08:36 PM
They've committed to only doing cold washes.  ever.  promise.   whistle

Don't know how to tell whether the fridge freezer is soft start?  The specs list 160W power, but 10A required??  http://www.balay.es/catalogo-balay/frio/combinados/3KSL5655.html?source=browse

All of the listed inverters offer generous surging abilities.  The 1300W studer for example will surge to 2800VA for 5 seconds.

Iain, I'm very green when it comes to using UPS for off-grid.  Initial look around shows that they can't handle the high battery voltage during EQ and they have high standing losses and self-consumption.  Happy to be educated otherwise :)


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: billi on May 06, 2014, 01:09:56 PM
Hiya

the Steca Solarix PI   1100 is as far as i know a nice little sine-wave inverter  , that could be paired as well   

on its own  perhaps too small but manages  3000 kva  for 5 sec .... should  cost less than  500 Euro ex Vat

Billi


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: stephendv on May 06, 2014, 01:32:24 PM
Thanks billi, it's an interesting idea but the size and price is a bit awkward.  A single 1000W solarix is well priced, but I'm worried about it not being able to handle fridge + washing machine.  And then 3 x 500W solarix is FAAAAR too expensive compared to Victron and xantrex.  Same with 2 x 1000W, which is well over 70% more expensive than a 2kW victron.


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: biff on May 06, 2014, 01:47:19 PM
Well the first thing about the Symmetra is that it,s voltage is 120 vdc,
                               That is not a problem but you need 10 x 12volt batteries to get it up and running.You also need good power coming in all the time.The Symmetra needs 200watt for itself,However if you have good power available like we have,3kw of PV and 1500watt of turbine,then the Symmetra is a brilliant buy.
   The only reason I bought the Symmetras was to actually use up surplus watts on the AC side of things in the old days when we had the big low wind speed blades on our wind turbine,Our wind turbine was at times,generating in excess of 3kws and the symmetra ticked all the boxs.
  Nowaday,everything is much more refined and genteel ::),Our original Chinese Iron core 2kw inverter never stops,unless I have some little job that required in excess of 3kws of power on a sunny day. (Lecky Chain saw) then I switch to the Symmetra but our Chinese jobby drives the washing machine and everything else.We fill with hot water manually.We have a Vax soft start Vacuum cleaner which is 2kw.Our Chinese concrete 2kw inverter drives this without setting off all the fans,even running for 30mins non stop,Our old 600watt Dyson which seems to be falling apart,but even when it was new,it made heavy work on the Chinese inverter setting off all the fans like mad.That is a bit hard to understand.Obviously,it looks like the Dyson was a lot more than 600watt.
           Years ago I installed a 48volt x 1kw controller/inverter.It had a solar input of 300watt.It never got any care and has ran non stop for over 6 years doing all kinds of nasty tricky jobs from driving drills,mixers,grinders.pillar drills,etc.I have overloaded it more times than I can count but the little man on the screen always smiled again when I switched it off and on to restart it. I regards these as simply bullet proof.It was the only controller/inverter I had available,originally for a 1kw wind turbine with digital amp and volt meters on the front.It has been left on.year after years 24/7 and dumping hot air during the daylight hours even as I type. I have no idea where you could buy this controller new at the moment,I bought mine years ago and the supply has dried up. I still see the odd one for sale on fleabay and the money is not big.I have never blown one of these, I have never blown one of the larger stand alone 2kw x 120vdc controllers either,even though I have cooked them to the point where the digitals clocks all went 8888888888 however when I plugged in a household fan and directed it across the circuit and the dumploads,then loaded the ac in the house,everything returned to normal and the same controller is working perfect to this day. I wish I could say that the Xantrex was as forgiving.
                                                                                                   Biff
  NB,this particular controller/inverter comes in one unit,with an ordinary household plug on the front. It even has 2 big resistors as dump loads but you best bypass those and connect to an immersion or something to keep the heat away from the actual unit,even though I have been used my resistors to warm the shed. The great thing about this controller/inverter is that it takes 3 phase from the wind turbine and solar from the array and of course a battery connection,so it is very much plug and play and very user friendly. The big letters on the front say it all. "MADE IN CHINA". ;D


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: Eccentric Anomaly on May 06, 2014, 02:44:27 PM
A single 1000W solarix is well priced, but I'm worried about it not being able to handle fridge + washing machine. 

Disconnect the fridge while the washing machine is running? It shouldn't warm that much in an hour or two.


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: billi on May 06, 2014, 07:11:57 PM
.... its a bit of a mystery  with start up  current ...  i probably  easy can sell  one of my 3000 kva  Victrons .... but my 1400 watt   waterpump seems  to like to run , while dishwasher or  washingmashine is on ....

I guess our whole house would   work on a single  3000 kva  Victron Multiplus  ( with a better  pump idea )


Not so sure why i would want to miss the internal charger , cause this is essential for AC coupling... so this could increase total AC     :D



Cu



Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: camillitech on May 06, 2014, 07:36:15 PM
Steer clear of Xantrex, their support is pants, the moment they stop making a product they stop supporting it or making spares. Studer are well made, perform better than they say and draw next to nothing at idle. Victron, well, there's enough members on here got them and I've never heard a bad word said. Funnily enough I've got all three makes and I'd be pushed to choose between the Studer and Victron but I wouldn't touch another Trace/Xantrex with a barge pole. I bought mine in 2006 and they stopped supporting it about six months later, it's never missed a beat in eight years of 24/7 operation right enough so it must be well made. However, once it breaks it'll be most likely fit for nothing more than the bin.

Good luck, Paul


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: Eccentric Anomaly on May 06, 2014, 08:12:58 PM
Paul, didn't you mutter a bit about Victron support a while ago, or am I misremembering?


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: camillitech on May 06, 2014, 08:45:10 PM
Paul, didn't you mutter a bit about Victron support a while ago, or am I misremembering?

Not me EA, I've never had anything to do with them but Billi has and he says it's good. What I may have said is that SMA and Outback have good support forums whereas Victron don't. Trace themselves used to have a great open one too but Xantrex pulled the plug on it and now it's 'dealers only'. Studer are very helpful if you don't mind phoning Switzerland but as far as I know Outback are the only people that will supply individual components rather than complete boards.

My take on inverters is this, and it could be complete tosh.

If you want to AC couple then go SMA, they're the pioneers and it's what they do well.

If you have a boat then go Victron, supported in every port and designed for Dutch barges with the marine market in mind, Victron are very big in the marine sector and it's what they understand.

If you're 'off grid' and into DC then go Outback, they were designed by 'off grid' people for 'off grid' use. It was the brains behind the original Trace Engineering that sold the company and went on to 'build a better mousetrap'.

If you want Swiss engineering in a camper or house then go Studer, they really are like a Rolex.

If you're skint, don't mind the huge losses in efficiency and don't need a charger then go UPS.

Sure, they'll all do the job and probably do it well, you 'pays your money and takes your choice' I guess, me I'm going SMA because 'AC coupling' works for me.

Cheers, Paul


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: Eccentric Anomaly on May 06, 2014, 09:21:59 PM
What I may have said is that SMA and Outback have good support forums whereas Victron don't.

Ah, that was probably it - must have misread. Thanks.


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: stephendv on May 07, 2014, 07:39:06 AM
Thanks all, going for the Victron because of it's popularity and future paralleling ability.


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: billi on May 07, 2014, 08:44:17 AM
Quote
If you have a boat then go Victron, supported in every port and designed for Dutch barges with the marine market in mind, Victron are very big in the marine sector and it's what they understand.....
If you want Swiss engineering in a camper or house then go Studer, they really are like a Rolex.

If you're skint, don't mind the huge losses in efficiency and don't need a charger then go UPS.

Sure, they'll all do the job and probably do it well, you 'pays your money and takes your choice' I guess, me I'm going SMA because 'AC coupling' works for me.

Are you anchored  in the last century Paul ?

Victron and Studer are big into off grid and especially  grid tied battery based FiT harvesting ideas ...
Studer  is the first Inverter company that i know of , introducing an off grid inverter that variable adds inverted battery power to AC house loads
Victron ....http://www.victronenergy.com/upload/documents/Whitepaper-Self-Consumption-and-Grid-independence-with-the-Victron-Energy-Storage-Hub-EN.pdf
You will see more and more DC ideas coming in future , cause the AC coupling storage ideas aint efficient  enough ...
some storage based systems like this http://www.dc24.de/dc24_stromspeicher_home/funktionsweise.htm (sorry in German )
are using MPPT chargcontrollers and batteries in the same voltage range as  the Grid tie inverter  so  PV power flows direct to Grid , battery and consumers , at night battery powers the same GTI to supply  as much  juice as power consumers  are on in the house

So it seems  some have learnt the lesson  , that a nightly supply of power is better done with DC coupling

SMA basically are a GTI manufacturer  that grew up in Germany while technology was needed for "Feed the Grid " ,

But sure the Sunny Island is a fabulous off grid inverter from SMA  ,

Billi












Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: stephendv on May 07, 2014, 08:52:10 AM
Speaking of Studer, have you chaps seen their new MPPT controller: http://www.studer-inno.com/?cat=mppt_solar_charge_controller&id=2101

Rated at 120A and with 2 independent MPPT trackers able to accommodate 900V solar array  whistle
Could be a very nice option to minimise wire losses and DC breakers on large systems.


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: Tinbum on May 07, 2014, 08:54:57 AM
At the moment I think the biggest problem in the UK is that there isn't an approved DC meter so to get FIT payments you have to go to AC and then back to DC.


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: camillitech on May 07, 2014, 09:18:07 AM
Interesting links Billi, I said it's my take and may be tosh. I still have DC inputs but AC works for me because of the large distances between my turbines and panels and the size of my mini grid. I have literally miles of cable in my AC grid supplying three properties seven sheds and one large agricultural building. Also I don't really plan on storing most of my energy in inefficient batteries but rather as water heated by AC.

Cheers, Paul


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: Eccentric Anomaly on May 07, 2014, 10:09:00 AM
Speaking of Studer, have you chaps seen their new MPPT controller:

Very interesting. I don't think anybody knows the price, yet, though:

http://www.photovoltaikforum.com/allgemeine-anlagenplanung-f69/pv-inselanlage-problemloesung-t98399-s30.html (http://www.photovoltaikforum.com/allgemeine-anlagenplanung-f69/pv-inselanlage-problemloesung-t98399-s30.html)


Title: Re: Recommendations for 1200W-2000W off-grid inverter
Post by: stephendv on May 07, 2014, 10:16:50 AM
Might be indicative pricing here: http://www.solarenergy-shop.ch/index.php?cat=KAT14&lang=DEU&product=P0762   ~ 1700 GBP.  Looking at the prices for the other known kit they stock like MS Tristar MPPT 60A, looks like that shop is very expensive in general.  Apply 0.52 derating to bring it down to realistic levels = 850 GBP.