Off Grid System in Victoria, Australia

RickeyH

We are in the process of building a new home in Victoria, Australia and due to the cost of getting power connected (anywhere from $30,000 to $50,000 depending on how much stone they strike - it needs to go underground around 400 metres from the pole to the property boundary) we are committed to going off-the-grid.

We estimate our requirements at around 5kwH per day. We will be buying mainly new appliances (fridge, washing machine etc.) so will ensure that we buy the most energy efficient items that we can afford. There is no requirement for electricity for cooking, heating or cooling so we are confident we can get by on 5kwH per day. I will have a workshop set up but I am happy to run the generator when necessary for power tools.

So, 5000 watt hours per day;

allowing for system losses and inefficiences, 7,500 watt hours per day

Solar Insolation for Mid-winter of around 2.17, gives an array size of 3456 watts.

We are constrained by the roof space available (we need panels that are relatively short) so we are looking at using the Daqo DQ190MFAa Series, 190W mono-crystalline modules. I currently have 6 of these installed on our machinery shed and they seem to be doing the job OK.

So, 20 modules at 190 watts gives us a 3,800 watt array.

Batteries:
Working on 5,000 watt hours required per day with maximum of 50% SOC means we need 10,000 watt hours per day. With 2.5 days of autonomy this becomes 25,000 watt hours. At 48 volts this becomes 521 amp hours. Rounding up I figure we need a 600amp hour battery bank.

Charge Controller:
A 3800 watt array with 48 volt system gives a charge controller amperage of 79 amps.
Looking at the Outback Charge Controller - Maximum Power Point Tracking - 80 Amp

Inverter/Charger
Looking at the Victron 48V 3000w Inverter/Charger and the Victron BMV-600s - Precision Battery Monitor

Generator:
I have looked at Chris Olson's sticky on Generator Support and it makes a lot of sense to me. Considering generators available in Australia I'm looking at the Honda EM50is

I am interested in your comments on what I have outlined. Have I got the mathematics right? Does it all look like it will work together?

I am considering buying the generator sooner rather than later to provide power during the build so I do need to make sure I get it right.

Thanks in anticipation
Rickey

zoneblue

Re: Off Grid System in Victoria, Australia

At a quick glance looks like your e heading in the right direction. Nice job. Without running the numbers id say that that gear will provide 5kWh/day happily. At a similar latitude we get 3kWh reliably out of less than half than in pv/battery.

Cariboocoot

Re: Off Grid System in Victoria, Australia

Welcome to the forum Rickey.

A bit different from the way I do it, so let's see how the math works out my way.

5kW hours per day on a 48 Volt system = 104 Amp hours. Multiply by 4 for 25% DOD = 416 Amp hours. Round up to an available battery size = 440 Amp hours (two parallel strings of eight GC2's). Good starting choice in case things go wrong - you won't be out big money on batteries.

What do you need to recharge that? About 2742 Watts of array minimally. Your Winter insolation is a real problem at 2 hours; you'd need to double the array to accommodate that. With those 190 Watt panels you'd want to round up to using sixteen at least for a 3040 Watt array. Twenty of them at 3800 Watts would also work, and should manage 3.9 kW hours AC in your Winter conditions.

I would not go for the 600 Amp hour battery bank. If you did the 3800 Watt array would be minimum and you will be running the gen more in bad conditions to stay charged. Plus you may have difficulty configuring such a battery bank from available units.

Now if you pick an inverter like the XW 6048 you can use gen support and get away with a lot of power out for big loads without having to buy a lot of panel and battery that wouldn't get used much of the time.

That Honda gen is 4.5 kW and may work, but it's not going to be the quietest or most economical. Maybe the EU65is instead?

On the whole I'd say you've got a pretty good working plan.

RickeyH

Re: Off Grid System in Victoria, Australia

Thanks Cariboocoot. I have been here before and you helped me configure the system for my shed. What do you think of these Surrette 12V 600Ah. Actually 450 amp Hrs. @20 Hr. rate. I can get them for around $650 Aus. Made in Canada, so must be good? ;-)

I'm interested in your thoughts on my not the Victron 48V 3000w Inverter/Charger . My understanding is that it does provide generator support so what do you see as the problem. Not enough grunt?

The other Inverter/Charger I was looking at is the Australian made Selectronic SPMC 482 AU Inverter Charger 48 V 7500 Watt 18000 Watt Peak. From their website

"Selectronic SP PRO Interactive Inverter Chargers use the battery bank to store excess energy from renewable sources (normally PV solar) for periods when power demand is low. When the power demand is too high for the inverter alone, or when the battery bank requires recharging, the inverter automatically starts a generator.

This unique range of inverter chargers allow sharing of the load between the inverter and the generator set to maximise power output capacity."

Certainly a step up in price from the Victron - around $8,000. XW 6048 is around $6,600

I'll check out the Honda EU65is.

Cariboocoot

Re: Off Grid System in Victoria, Australia

RickeyH wrote: »

Thanks Cariboocoot. I have been here before and you helped me configure the system for my shed. What do you think of these Surrette 12V 600Ah. Actually 450 amp Hrs. @20 Hr. rate. I can get them for around $650 Aus. Made in Canada, so must be good? ;-)

Probably made on Wayne's side of the country and shipped via slow boat to Australia.
I'm not a big fan of Surrette batteries. The price, the operational specs, the recent issues with some ... just put me off the brand. But you are in a different market so I can't say how they compete against other brands in your neighbourhood.

I'm interested in your thoughts on my not the Victron 48V 3000w Inverter/Charger . My understanding is that it does provide generator support so what do you see as the problem. Not enough grunt?

For a full-size house running everything, including no doubt A/C, 3kW might be skimpy at times. There usually isn't much difference in price or inverter consumption in going up to 6kW and it's nice to have the capacity if needed. Maybe Victron has a bigger model? We don't get them here.

The other Inverter/Charger I was looking at is the Australian made Selectronic SPMC 482 AU Inverter Charger 48 V 7500 Watt 18000 Watt Peak. From their website

Certainly a step up in price from the Victron - around $8,000. XW 6048 is around $6,600

No experience with Selectronic either. It does seem pricey. An Outback Radian can be had for half that in the US. How are they priced there?

I know that several of the forum members in Europe have Victron equipment and are quite happy with it. I'd count that in favour of the brand.

RickeyH

Re: Off Grid System in Victoria, Australia

7000 watt Radian Inverter Charger - Outback Power GS7048 $7,272.00 AUS.

niel

Re: Off Grid System in Victoria, Australia

rickeyh,
would it be possible for you to expand on the pvs a bit more? like 4 more? i ask this as you are pushing the cc to its max nearly all of the time and to split the pvs to 2 arrays feeding 2 mppt ccs might make better sense. this would be 12 pvs per cc. you could lower to the 60a variety mppt cc going with 2 or stay with 2 of the 80a so as to expand on the system.

i should mention that if you also have room on the property that you could employ pole mounts either with or without mounting on the roof too.

got to add you will need combiner boxes and either fusing or circuit breakers too.

RickeyH

Re: Off Grid System in Victoria, Australia

Thanks Niel.

I was wondering about the charge controller. I reckon I can squeeze 24 panels onto the roof. So, 2 of the 60amp charge controllers might be the way to go. I used a Midnite Solar Combiner box on the shed and was planning to use the 6 position box with circuit breakers for the house. Might need to use the 12 position - will have to work out how many strings I need.

Rickey (not employed by anyone) ;-)

stephendv

Re: Off Grid System in Victoria, Australia

Hi Rickey,

The victron does have the gen support feature, but you may have to get the PC communication cable to program it properly, or else you'll be stuck with the factor defaults. They also do a 5kW unit. We have a 5kW Sunny Island for our home and the only times I've ever seen it pull more than 3kW is when the 1.5kW well pump is on as well as the kettle or breadmaker. If you don't have these types of heavy consumers then 3kW should be fine.

RickeyH

Re: Off Grid System in Victoria, Australia

Thanks Stephen,

I will check out the documentation for the Victron. We have a reasonable slope on the block so plan to put a 5,000 gallon header tank on top of the hill and gravity feed back to the house. Around 15 metres of head. We will pump to the tank during the day using a 24 volt pump using the solar system I have set up on the shed. See my signature block. Apart from the workshop (which I will basically run off the generator) the biggest loads in the house will be a fridge and freeze.

The Xantrex inverter suggest by Caribcoot does look pretty handy though and seems reasonably straight forward to connect and program. Might come down to money in the end.

stephendv

Re: Off Grid System in Victoria, Australia

$AUS 4,425 for the 5kW Victron and $AUS 3,147 for the 3kW unit. On the victronenergy.com page, there's a "where to buy link" where you can find resellers and prices in aus.

For fridge +freezer you really don't need more than 3kW especially if they're new and energy efficient.

SandyP

Re: Off Grid System in Victoria, Australia

stephendv wrote: »

For fridge +freezer you really don't need more than 3kW especially if they're new and energy efficient.

Go for the Electrolux ETM4200SC fridge : only 349kwh/year (<1kwh/day)

RickeyH

Re: Off Grid System in Victoria, Australia

Thanks SandyP - do you speak from experience?

BB.

Re: Off Grid System in Victoria, Australia

What are your plans for a well pump? That will be the other big surge device for most people.

And how large of battery bank are you looking at? To run a 6kW AC inverter flat out, a 600 AH battery bank @ 48 volts is a good minimum recommendation. (100 AH per 1kW @48 volts, 200 AH per 1kW @ 24 volts, 400 AH per 1kW @ 12 volts is one of our design rules of thumbs).

-Bill

newl

Re: Off Grid System in Victoria, Australia

Most bores here aren't suitable for drinking water so we tend to use rain water (or call in a truck load when needed) so I'd feel that he'll be collecting from the shed to a large tank (90-120k liters is typical) and then pumping to the header tank and then gravity feed the house.

petertearai

Re: Off Grid System in Victoria, Australia

Hi been using those surette batts for 2 years now in NZ. Good so far.

RickeyH

Re: Off Grid System in Victoria, Australia

Thanks everyone - I've been away for a couple of days and haven't had access to the Internet. Yes, we have a 120,000 tank for drinking water and will pump to the header tank using the solar system on the shed. Good to know about the batteries Peter as they seem to be very reasonably priced.

Bill, Cariboocoot recommended a smaller battery bank than I was initially planning. Most of the year we have plenty of sun. We are at 500 metres altitude and even in winter have glorious clear skys - just not for very long. I like what Chris Olson suggests in his post on generator support. I can't see the point in buying a maintaining a huge battery bank for those relatively rare occasions when we need extra power. I have no problems with running a generator where necessary.

Regards
Rickey

RickeyH

Re: Off Grid System in Victoria, Australia

Okay, if I go with 24 Daqo DQ190MFAa Series, 190W mono-crystalline modules as suggested by Niel

Electrical Characteristics
Maximum power at STC - Pmax 190 W
Open-circuit voltage - Voc 45.5 V
Optimum operating voltage - Vmp 36.5 V
Short-circuit current - Isc 5.3 A
Optimum operating current - Imp 5.21 A
Operating temperature 45 °C
Series Fuse Rating 10 A
Maximum system voltage 1000 VDC

Temperature Coefficients
Short circuit current temperature coefficient - 0.06 % / K
Open circuit voltage temperature coefficient - 0.31 % / K
Peak power temperature coefficient -0.40 % / K

And the Xantrex XW 6000W 100A 48VDC Inverter Charger, Xantrex 865-1060 XW Automatic Generator Start and the Honda EU65is High Capacity 6.5kVA Commercial Generator. Surrette 48V 600Ah battery bank (8 at 6volts)


What charge controllers (I'm thinking I will need 2 with the 12 modules wired into each) do you recommend? Would staying with Xantrex make it easier to configure the automatic generator start or wouldn't it really matter?


Thanks
Rickey

westbranch

Re: Off Grid System in Victoria, Australia

Aer you asking about 1 series string per CC? ie 12 x 45.5v = 546V VOC?

RickeyH

Re: Off Grid System in Victoria, Australia

Nope - talking about having 12 modules on each charge controller but the number of modules in a string would need to be determined by the charge controller chosen.

I thinking it will need to be something like 4 strings of 3 on each controller?

westbranch

Re: Off Grid System in Victoria, Australia

Well what will the system voltage be is where you need to start. If 48v you will need an Vmp of ~69V for charging, so 2 in series gets you there, 73.0 V by name plate but then you have to derate for hot panel temps... and so it goes. The V you need will be set by your batteries manufacturer... and then a bunch of fine tuning for your actual site conditions.

hth

RickeyH

Re: Off Grid System in Victoria, Australia

It will be a 48 volt system. My major concern is to have a system that is relatively easy to program for the generator support. From this perspective does it make a difference if I don't go for the Xantrex charge controller as all the configuration of the generator is through the inverter/charger?

Cariboocoot

Re: Off Grid System in Victoria, Australia

The inverter can handle the AGS on its own; it does not need to communicate with the charge controller to do this.

RickeyH

Re: Off Grid System in Victoria, Australia

Thanks Cariboocot.

So the question is then which charge controller. Could I get away with a single Midnite Classic 150V MPPT Solar Controller? Their sizing tool says that if I had 12 Parallel strings of 2 modules then the Classic 150 would be fine. I do realise that I would need a combiner box to handle 12 strings but it would be a lot cheaper than getting a second charge controller.

Thoughts?

Rickey

Cariboocoot

Re: Off Grid System in Victoria, Australia

I wouldn't go with twelve strings if possible.
The Voc on your panels is a whopping 45.5, so three in series would be 136.5. Add a touch of cold temps and you could be pushing it with the Classic 150. The 200 would be a sure-thing to handle it, and might even be acceptable with four in series (getting into reduced controller efficiency here).
With 24 panels total, eight strings of three on the 200 or six strings of four. MidNite makes some nice combiner boxes, including a six position.

If I'm reading it right, you'd have an array like this:
Twenty-four 190 Watt panels, 4560 Watts total.
String of four panels: Voc 182, Vmp 146, Imp 31.26, Isc 31.8.
Maximum controller output current around 73 Amps.

SandyP

Re: Off Grid System in Victoria, Australia

RickeyH wrote: »

What charge controllers (I'm thinking I will need 2 with the 12 modules wired into each) do you recommend? Would staying with Xantrex make it easier to configure the automatic generator start or wouldn't it really matter?
Thanks
Rickey

Based on discussion from another thread, the benefit of having Xantrex charge controller(s) will be that you can configure your system to stop the absorb stage of charging using end amps as the charge controller know the charge amps and the inverter will know the load amps thus the system will know the actual amps going to the batteries.

PS. Our Electrolux ETM4200SC works well.

niel

Re: Off Grid System in Victoria, Australia

a single classic will not work as 4560w/48v=95a and that is over the rating of the cc.

RickeyH

Re: Off Grid System in Victoria, Australia

I've been playing around with the placement of the panels on the roof and I reckon I can get 18 of these to fit.

DQ250PSC, Daqo 250W poly-crystalline cell

Open Circuit voltage Voc (V) 37.2
Short circuit current Isc (A) 8.72
Maximum power voltage Vpm (V) 30.5
Maximum power current Ipm (A) 8.2

Plugging the details into the MidNite Solar Classic Sizing Tool shows me that 6 strings of 3 modules would be OK on Classic 150.

Wattage of array = 4500, Max. allowed by the Classic 4847 so OK

What do you think?

Rickey

niel

Re: Off Grid System in Victoria, Australia

nothing wrong with redoing it with a different pv if they fit. many of the pvs in the range of 250w are higher efficiency so you may maximize your collecting a tad better for the space. in fact if you went with 15 pvs in a 5 x 3 arrangement that it would be close to the original 20x190w pvs you had planned which was 3800w and 5x3 with 250w pvs is 3750w. if they were 255w pvs then 15x255w=3825w and would be 25w over the original 3800w proposed array with only 15 pvs. play around with it and then decide how you'd best like to proceed with it.

RickeyH

Re: Off Grid System in Victoria, Australia

I have been advised the the supply and support for Xantrex products in Australia has 'fallen apart' since Schneider took over. They recommend either the Outback Radian; 7000 watt Radian Inverter Charger - Outback Power GS7048 or the Studer Xtender XTH6000-48 6000W 100A 48VDC Inverter Charger. The Radian retails for $7,272 and the Studer for $6750.

Has anyone any experience with either of these? Specifically, I looking at hooking them up with the Honda EU65is generator with auto-start capability.

To recap:

18, 250W Daqo panels (6 strings of 3) and 8, Surrette 6V 600Ah batteries for a 48 volt system, 1 Midnite Classic 150 Charge Controller

Thanks
Rickey

SandyP

Re: Off Grid System in Victoria, Australia

RickeyH wrote: »

I have been advised the the supply and support for Xantrex products in Australia has 'fallen apart' since Schneider took over. They recommend either the Outback Radian; 7000 watt Radian Inverter Charger - Outback Power GS7048 or the Studer Xtender XTH6000-48 6000W 100A 48VDC Inverter Charger. The Radian retails for $7,272 and the Studer for $6750.

Has anyone any experience with either of these? Specifically, I looking at hooking them up with the Honda EU65is generator with auto-start capability.

To recap:

18, 250W Daqo panels (6 strings of 3) and 8, Surrette 6V 600Ah batteries for a 48 volt system, 1 Midnite Classic 150 Charge Controller

Thanks
Rickey

Looking at your first post it appears your proposed power needs/use must have increased, if not you could consider the Outback FLEXpower One System for ~$6,000 for a complete package.

VFX3048E 3kW FLEXpower ONE - Pre-wired AC and DC boxes with 230Vac Bypass - European Outlet - 175A DC breaker - GFDI - 80 Amp charge controller breaker - MATE2 - HUB4 - RTS - FLEXmax 80 - FLEXnet DC and surge protector