Energy Matters Forums

[davidg]

Indeed it is, quite relevant considering Kurt's location!

?? I thought he was in QLD

[offgridQLD]

Yes sorry for the confusion David. My forum handle isn't really reflecting my current situation. I moved late last year from QLD to the southern Adelaide hills.

The house and shed is being built now. I have power on the farm 3 phase though because it's 190 acres the power is going to irrigation pump sheds and a old dairy about 500m away from the house so I have ruled that out. (perhaps a large 3 phase grid tie system in the future to reduce irrigation costs)

The new house and shed location are about 30m away from the east boundary line fence. I share this fence line with my old mans farm.

He has a unused 10kva transformer on a pole that's 100m away from my east fence line (was a old shed there many years ago but no longer there so transformer is free). So I can dig a trench 30m to the boundary on my side then 100m to that pole on his land (total distance 130m) I have spoken to SA power networks they don't have a issue with it. Just a $800 connection fee. Though they said they would require a easement or at least show them the paperwork is under way for the 100m trench in my old mans land before they will connect to the pole. That's fare enough.

That 100m easement could be a $4000 cost by the time I pay for surveyors and conveyancer title changes and so on.

Then you have the cost of the trenching to 600mm deep over that distance the trencher I have access to for my tractor isn't a good match for the soil in that location so it's a payed job for that excavation. cost to be determined but wont be free

Then the cable cost for that 130 - 140m run of single phase. Considering I want to run a good size PV and run reasonable loads voltage drop in each direction over that distance will require a heavy run of copper perhaps 70 or 90mm2 at considerable expense.

That would get me to the point where I can start paying for grid power at full cost.

Then the cost of any grid connect pv or hybrid system.


I need to compare the above to any offgrid options I would undertake.

kurt

[davidg]

Yes sorry for the confusion David. My forum handle isn't really reflecting my current situation. I moved late last year from QLD to the southern Adelaide hills.

Hmm... suggestion put in the RHS your location, that could resolve confusion , well it would for me anyway

Yep all those costs are pretty normal and of course they add up as well.

I did all the costs for our farm and by the time they wrere added up I decided on SPS.

By the way a thought.
You maybe able skip some of the costs by having the service from transformer to fence line as one part meter at fence line, the rest of the cable run is private and your problem.

I could suggest another option but it's questionable as to how it is from a distributor point of view.
Electrically it would perfectly safe.

[australsolarier]

there shouldn't be confusion where Kurt is planning his new system. just read the first post of the thread.

[offgridQLD]

By the way a thought.
You maybe able skip some of the costs by having the service from transformer to fence line as one part meter at fence line, the rest of the cable run is private and your problem.

As in pay my old man to have a trench dug with 100m cable from transformer pole to fence line then put a meter box in on the fence line. The have dual meter in that distribution box?

I may not have been clear but his land is on the left of that picture (100m length) my land is on the right (30m trench)

I think the issue is although its family on the other side of the fence from a legal viewpoint I'm sure some kind of easement would have to be involved as power is still being accessed over another party's land that's on a different title.

[offgridQLD]

australsolarier

I'm very familiar with the Midnite classic 150 charge controllers as I ran them for 6 years in my previous offgrid system. I found them very easy to program. I also ran a selectronic PS1 I also found that very easy to program.

What I didn't like about the classic 150 was no option to measure battery voltage remote. Can be a small issue when your running big power and trying to measure fine accuracy with voltage drop. Though not such a big issue around V absorb at the pointy end as current is usually very low and that's where you want good voltage control. Though I still think they could implement this feature by measuring voltage at the WBJR shunt and reporting it to the classic.


the 2nd issue is the classic has fans and eventually they wear out. Though they did make them much easier to replace on newer models.

3rd issue is the power terminals on the classic are a bit under done though can work around that with a good reducing boot lace ferrel.


Over all I still like the classic and it was the hart of the android based monitoring app that I used in my last system.


I hear you points on the battruim BMS. +/- 50mv sounds crazy considering it's trying to balance to 10mv... I remember investigating this some time ago and from memory the response from batrium was that in practice the Voltage measurement accuracy was way better than the listed specs. Worth finding out the reality. perhaps some improvments have been made on version 4 and latest logmons? (Im resonably sure they are user voltage offset calabratable now to 10mv).https://batrium.zendesk.com/hc/en-us/articles/203890399-How-to-Re-Calibration-the-CellMon-voltage

Australsolarier , how did you find there accuracy in practice...Do you have good reference meter to judge them. As in given a stable 1A charge rate and setting them at 3.51v. That's your meter reading on individual cells across the board? ( My plan was to spend a few weeks with the unit and the bank on the bench in ideal / controlled conditions. to see just how well they perform monitoring them with a calibrated HP bench meter and fluke 87v. Consistency from one celmon to the other is what I want to see.


Yes I understand a 250A contactor or two is needed for the BMS I have a good contact (no pun intended) to abtain Gigavac contactors at a good price.

Im not that fussed about the monotoring software of the SP pro. I like all the setup features but once set localy I wouldnt have a real need to use them day by day.

[australsolarier]

Kurt,
concerning batrium, yest they are better than 50mv - +. i had however one that showed 40mv too much, i just bought 2 new ones. i contacted batrium ( Maxine) and yes they are calibrated, and maxine said yes usually much better than 50mV, but for some weird reason they do not want the customer to calibrate them themselves. according to Maxine someone was doing calibrating under high current situation ?????. most are so around 10 to 20mV accurate. the 50mV - + tolerance are in the batrium specification.
an other weird thing with batrium is their current shunt. whilst it is the same like being used for the midnite jr whizbang and can be hooked up to the selectronics, for the batrium the current measuring device is calibrated individually to each shunt. i think it is bizarre. i hooked it up the the midnite current shunt anyway. the thing measure assymetrical! different measurement what is going in and out. again this cannot be calibrated by the user. so it makes it much more expensive to begin with.
agree with your points on the midnite classics. as for a future fan problem i installed external fans underneath. besides better cooling i hope the much reduced internal fan use will not make it necessary to change fans inside the midnite. and even though in the new models it is easier to change the fan, it is still a major hassle to change the fan. you have to take them off the wall and to do this you have to take off all the wires. in my case the wires are quite stiff.
as for the inferior terminals, seemingly they never considered high currents when designing the midnite. and yes it requires considerable time to manufacture a 35mm wire connecting to the terminals.
the midnite is very sluggish in float mode. it takes minutes for it to ramp up to a largish current draw. (kettle or something) and then takes an even much longer time to bring it up to full float. (unless rebulking is triggered) it has something to do with the stiffness of lithium batteries and is probably not a problem with lead acid.

[davidg]

seemingly they never considered high currents when designing the midnite. and yes it requires considerable time to manufacture a 35mm wire connecting to the terminals.

35mm2 for a couple of meters is overkill 16mm2 is fine, (if you require a longer distance 300mm tails and then upto a bigger cable is quick and simple to do) and more than capable of carrying the current, with minimal voltage drop. I find the whizzbang jnr seems to help it respond in no time flat to current drain jumps with no problem.

[offgridQLD]

I agree with David I had very fast response time to loads on my classics. just when you really loaded it up with very large loads the classic would hold a voltage slight lower then the true battery V at the terminals. I haven't been on the Midnite forums for a long time but if enough people request it they could implement remote monitoring of voltage through the wizbang. that said I got the impression that further development on the classic had been put to the back burner at midnite.

I think I was running cable a tad under 25mm though a short 2 foot run from a nt00 fuse isolator with 95mm2 on the other end of the isolator.

My point on the classic was just the terminals are a bit under baked. You get away with it but would have been nicer to see say 4 x 6 or 8mm studs there on some flat bar with a plastic isolating shroud.

I would still pick the classic this time round as the positives make up for any shortcomings and it could be a case of better the devil you know than the one you don't.

David, thanks for the PM I will give you a call tomorrow for a quick chat.

Kurt

[offgridQLD]

In my last offgrid system I didn't use my AutoStart generator as I was lucky to be in the sunshine coast QLD. A bit of power conservation for a few days a year was all it took to get by ( A large PV array helped).


Now winter in SA is a little different . Though I will up the array size even more to compensate. looking back on our first SA winter Well not our first but i'ts been 20 years. So I forgot what they were like ) I think there will be some genset necessary in the dead of winter.

Bellow are the specs of the genset I am considering. One thing that a was really surprised by was the efficiency. Fuel Tank Capacity :95 Litres (-/c Fuel Gauge) Running Time :47 Hours Continuous (prime load)Fuel Consumption :2 Litres/Hour (prime load)

At 2lt hr producing 8kw that's 4kw /1lt of diesel or at $1.40lt that's 35c - Kwh I wouldn't complain about that considering it's 40cents kwh from the grid. That said I'm kind of questioning the specs as it sounds a little to good to be true.

Kurt.

Prime Power :
8kW / 8kVA 240 Volts 33Amps
Standby Power :
8.8kW / 8.8kVA
Power Factor :
1
Phase Voltage :
Single Phase 240 Volt
Frequency :
50 Hertz
Engine :
OEM 3 Cylinder Diesel
RPM :
1500/min
Cooling Method :
Water Cooled - Rated For Australia's North
Alternator :
Single Phase 4 Pole Brushless Synchronous -/c AVR
Starter System :
12 volt Electric - Battery Included
Controller :
Smartgen HGM4010N

2 Wire / Remote Start Capable

Over Temperature Protection

Over Current Protection

Low Oil Protection
Safety Systems :
Battery Isolator

Emergency Stop

Failsafe Shutdown Fuel Solenoid
Noise Level :
65 dBA at 7 metres
Fuel Tank Capacity :
95 Litres (-/c Fuel Gauge)
Running Time :
47 Hours Continuous (prime load)
Fuel Consumption :
2 Litres/Hour (prime load)
Chassis Enclosure :
Lockable

Sound Deadening Throughout

Weather Resistant Powder Coating

Stainless Steel Fittings

External Use
Mine Site Ready Bunding :
No
ATS (Mains Failure) :
Easy Connect Plug (ATS Box Optional)
Single Phase Outlets :
2 x 15 Amp IP66

1 x 32 Amp IP66
Three Phase Outlets :
No
Hardwire Terminals :
No (Use 32 amp Global Socket)
RCD :
Australian Standard (IP67 Enclosed)
Options :
Automatic Start Systems

GSM

Timer

Synchronisation

Wireless Remote

Solar System Compatible (Majority)

ATS (Mains Failure Detection / Auto Transfer Switch)

Minespec Padlockable Battery Isolator
Weight :
570 kg
Dimensions :
153 L x 78 W x 108 H cm