Saskatchewan off grid questions

[Matt C]

Ok so I’m planning a new build, will be approx 2800 sqft metal building with infloor radiant slab heating. Will be using an outdoor wood boiler for heating floor and domestic hot water. I currently have a 5.4kw solar grind tie in setup but use a 50kbtu instant boiler for my radiant heat so huge electrical useage! In saying that when not running the heat im using 330ish kwh per month, so that would be my similar load for the new house maybe less as everything will be LED etc.

So my question i guess would be what size battery bank would be ideal for my use? Been reading lots on those lifep04 banks. But not sure if 48v or 24v is what i should run. Will have to do solar maybe 20 of those 330v panels from Canadian Solar. Then a heavy duty inverter and charge controller would be needed?

Im leaning towards an off the grid setup because the new property currently has no power and its $30k for a transformer to be run to the property plus hook up to the panel.

Was thinking i could build an off grid setup for less then that and not be a slave to the power company.

 

[snoobler]

330kWh/month = 11kWh/day - pretty modest.

That's the basis for the battery bank size for each day you want of backup power. For FLA/AGM batteries, divide the daily kWh by 0.5 to get the capacity you need. For LFP, divide by 0.8.

Use link #5 in my signature for your location, panel orientation and tilt. Find the lowest hours by month. Divide 11,000 by that number - that's the minimum array size you need to feed your 11kWh daily usage.

Charge controller flows from the amount of solar you need, and inverters flow from how much power you need to provide simultaneously.

You can likely build a very robust system for less than $15K.

 

[Matt C]

There was no signature that i could see to do the math on the solar array.

Yes i do feel the same about getting a good system for 15k but having trouble figuring the batteries out. So essentially 8 cells at 3.2v 280ah would be a 7kw output? 8x3.2x280=7168w

 

[Hedges]

Of your 11 kWh/day, how much is drawn at night, and how much while the sun shines?
Minimum usable battery is enough Wh to make it from sundown to sunup.
Some people shoot for enough battery to go 3 days without sun.
With a backup generator you don't need as much extra battery capacity.

Lithium is supposed to have thousands of deep (80% maybe 90%) cycles, so even deeply discharged every night could last 10 years.
Lead acid has a range of cycle life depending on type, but if sized for one night is likely to get replaced several times in 10 years. If sized for 3 days usage will typically only cycle 16% DoD so could last 10 years, maybe 20 years for forklift type batteries.

20, 330W panels is 6600W STC. Might produce 30 kWh/day in the summer, 12 kWh/day in the winter, so could be good for your needs. Use a website to evaluate your location and weather history.

If batteries are small compared to PV array, check that the charge rate will be acceptable.

 

[snoobler]

There was no signature that i could see to do the math on the solar array.

Yes i do feel the same about getting a good system for 15k but having trouble figuring the batteries out. So essentially 8 cells at 3.2v 280ah would be a 7kw output? 8x3.2x280=7168w

Turn your phone sideways.

 

[Matt C]

Turn your phone sideways.

Ok so it didnt work for Canada so used Minot ND for the numbers which is a few hrs from me.

So Jan was lowest at 1.27kwh/m2

So 11000/1.27 = 8,661w so i would need a min of 8.6kw solar array to make the 11kwh i use daily?

Will have a diesel miller welder on hand for my shop and to charge batteries if need be.

 

[snoobler]

This is for Regina with a optimal panel tilt of 40° from vertical or 50° from horizontal:




1.76 is the worst number here.

It's better to use something North of you vs. South of you.

11000/1.76 = 6250W

A generator is always a good option.

 

[Trukinbear]

A generator is always a good option.

That far north, unless you want to replace your batteries often a generator is a necessity.

 

[Matt C]

That far north, unless you want to replace your batteries often a generator is a necessity.

Im not that far north but yea i would have a generator on hand for running my big TIG welder and MiG. The controller/inverter im looking at as an auto generator start feature.

 

[Trukinbear]

Nowhere near as far north as you here at the 42nd parallel N. I've got 18 - 330W panels and a 6kw inverter with similar (15Kw/D) usage and this time of year the generator runs every day (I haven't seen the sun in a week), in the summer I still need the generator to provide scheduled 'full' and 'equalization' charges.

 

[Hedges]

Nowhere near as far north as you here at the 42nd parallel N. I've got 18 - 330W panels and a 6kw inverter with similar (15Kw/D) usage and this time of year the generator runs every day (I haven't seen the sun in a week), in the summer I still need the generator to provide scheduled 'full' and 'equalization' charges.

For summer I'd think sufficient over-paneling could do that.
Or maybe schedule shutting off enough loads for a period of time to let existing 30 kWh/day of panels do that. Aren't they about 60% of battery capacity?

 

[Trukinbear]

Ok so it didnt work for Canada so used Minot ND for the numbers which is a few hrs from me.

So Jan was lowest at 1.27kwh/m2

So 11000/1.27 = 8,661w so i would need a min of 8.6kw solar array to make the 11kwh i use daily?

Will have a diesel miller welder on hand for my shop and to charge batteries if need be.

11000x1.27 = 13,970 you'll need to make 11KwH/D

 

[Matt C]

Im not that far north but yea i would have a generator on hand for running my big TIG welder and MiG. The controller/inverter im looking at as an auto generator start feature.

Nowhere near as far north as you here at the 42nd parallel N. I've got 18 - 330W panels and a 6kw inverter with similar (15Kw/D) usage and this time of year the generator runs every day (I haven't seen the sun in a week), in the summer I still need the generator to provide scheduled 'full' and 'equalization' charges.

What setup do you have for batteries and when how long do you run your generator for?

Im really interested in how the off grid as been for you, what you would change or any special routines you need to do. My wife doesnt want to comprise from her daily comforts.

Its rare that we go more then a couple days without sun here.

 

[Steve_S]

The controller/inverter im looking at as an auto generator start feature.

Just because an Inverter/Charger has AGS (Auto-Gen-Start) signalling you still have to get a GCSM (Generator Start Control Module) and not all Generators, even with electric start & auto-choke are capable of being started by such a module. As for Home Stand-By Generators like those from Generac, Champion and so on, are NOT useable by these systems, nor are they approved / support by the companies to do so.

Have at look at these, this is more or less the #1 company to deal with and best bang per buck.
GSCM-mini-60Hz (USA & Canada) (atkinsonelectronics.com)

Search THIS LIST with the Generator Make & Model you have in mind to use. If it is NOT there, there is likely no chance that you will find a GCSM from anyone to support it. All Hookup Diagrams Merged.pdf (atkinsonelectronics.com)

I'm up near Algonquin Park Ontario 45 degrees, 4 days of LFP & 3 days of FLA Battery. genset runs once a week fro 9 hours in mid winter.

 

[Matt C]

11000x1.27 = 13,970 you'll need to make 11KwH/D

That number is wrong it was 1.78 for Regina in Dec so it would be 6200Watts. Its posted above.

 

[Trukinbear]

My generator is completely under the control of my SI6048 Inverter/Charger - somewhere around 3hrs a day this time of year, though the weekly full charge is 6+ hours, and my monthly equalization charge is near 10. If I had it all to do again the only thing I would change is where my panels are, my roof is not inclined 63 degrees but rather 10 degrees so I'm less efficient than I could be in the winter, but awesome in the summer when we use most of our power. We have 2 energy star residential refrigerators, a deep freeze, tankless LPG water heat, LED lights, TV's and computers etc... and an inverter-based mini-split heat pump. My mom is on a respirator, and my son is special needs - neither one knows we aren't on the grid, or why. We didn't change our lifestyle... If we use too much power at any given time the inverter just cranks the generator up - no problem.

Go with the highest voltage battery system you can, and use an inverter that can control your generator.

 

[Matt C]

Just because an Inverter/Charger has AGS (Auto-Gen-Start) signalling you still have to get a GCSM (Generator Start Control Module) and not all Generators, even with electric start & auto-choke are capable of being started by such a module. As for Home Stand-By Generators like those from Generac, Champion and so on, are NOT useable by these systems, nor are they approved / support by the companies to do so.

Have at look at these, this is more or less the #1 company to deal with and best bang per buck.
GSCM-mini-60Hz (USA & Canada) (atkinsonelectronics.com)

Search THIS LIST with the Generator Make & Model you have in mind to use. If it is NOT there, there is likely no chance that you will find a GCSM from anyone to support it. All Hookup Diagrams Merged.pdf (atkinsonelectronics.com)

I'm up near Algonquin Park Ontario 45 degrees, 4 days of LFP & 3 days of FLA Battery. genset runs once a week fro 9 hours in mid winter.

I would have a Miller diesel welder/genset, it most likely doesnt have auto start but if i have to go out and push the button to start it i dont mind.

 

[Trukinbear]

That number is wrong it was 1.78 for Regina in Dec so it would be 6200Watts. Its posted above.

I'm FAR south of that and MY 6000 watts of panels seldom makes more than 10KwH/D on our brightest sunniest December or January day.

 

[Trukinbear]

last month

 

[Matt C]

My generator is completely under the control of my SI6048 Inverter/Charger - somewhere around 3hrs a day this time of year, though the weekly full charge is 6+ hours, and my monthly equalization charge is near 10. If I had it all to do again the only thing I would change is where my panels are, my roof is not inclined 63 degrees but rather 10 degrees so I'm less efficient than I could be in the winter, but awesome in the summer when we use most of our power. We have 2 energy star residential refrigerators, a deep freeze, tankless LPG water heat, LED lights, TV's and computers etc... and an inverter-based mini-split heat pump. My mom is on a respirator, and my son is special needs - neither one knows we aren't on the grid, or why. We didn't change our lifestyle... If we use too much power at any given time the inverter just cranks the generator up - no problem.

Go with the highest voltage battery system you can, and use an inverter that can control your generator.

Oh wow thats great to hear! Thanks for the response. Sounds like you have a great system keeping your family in power. Im looking at a 48v lifePo4 battery pack. What do you run?

Also i was thinking on mounting the panels on a ground array as i currently have roof mounted grid tied 300watt panels and do loose some power in the winter from angle.