Hi Guys,
Im new to the forum and the world of off grid, and could use some hints and pointers in system selection for a tiny house with space constraints.
Ive picked a few items that I know will fit physically, that are within budget, and should theoretically meet my electricity demands.
Ill start with demands
Tiny House will be stationary and parked permanently next summer, no grid available. 3hrs north of Toronto. Can see -30C in winter. Currently parked in a place where a long 15amp run serves up about 700 watts before voltage drop is too great.
Average calculated KW usage per 24 hrs is expected to be somewhere around 2.0 to 2.5 on battery power. I arrived at this:
-1500watt 6gal water heater. 20 minutes from cold to hot. = 500 watts-ish. One heat cycle per day for shower, well insulated, on a switch. Extravagance = 1000watts
-5 LED lights on, 10w x 5 = 50watts, say 6 hrs a day as a composite = 300 watts
-Efficient 4.5 cu ft AC fridge w/ mechanical t-stat = 600 watts/24hrs
-RV Water pump 80w x 1hr = 80 watts
-Compost toilet fan 2w x 24hrs = 48 watts
-Laptop computer 25 watts x 4hrs = 100 watts
-Radio 10 watts x 5hrs = 50 watts
-LED TV 40 watts x 2 hrs - 80 watts
-Incidentals ie vacuum, coffee grinder, various little battery chargers, water pik, etc. 200 watt hours?
All of the above w/ extravagance showers = 2458 watt hours x1.07 for 93% inverter efficiency = 2630 watts.
I also dont intend to pull much more than 2000 watts continuously off the inverter on battery only, and not for long (20 minutes to get hot water + lights and stuff simultaneously).
The two infrequent appliances Ive listed below I do not intend to run off battery. If its sunny out and I can pull enough juice from the array, then I will use one of the below at a time with the batteries helping out. If its winter and I need clean clothes or laundry, then I will use a generator to stuff amps back in the bank while doing dishes or laundry.
Full 24 Energy efficient new dishwasher
24 Clothes washer
Here’s what I’ve picked to start with…
Phase One Purchase (Very Soon)
Magnum MSH4024M. 24V Mobile Hybrid inverter with load support, 4000 watt 120v, but I don’t need anywhere past 3000 watts at the absolute most w/ load support, extra capacity will be nice for surge. Has automatic neutral-ground switching for shore power or genset.
Appropriate 4/0 cabling, battery monitor w/ shunt, fused w/ disconnect, etc.
Magnum advanced remote
Proper AC disconnects and breakers
AC and DC ground to trailer frame
Midnite Solar SPD wired to shore power and sub panel.
4x Surrette Rolls 6v 335 AH AGM. The spot under the couch only measures 24.5”w, 20.25”D, and 15”H, so these fit nicely. I think they have a C/4 discharge rate? Should support bursts of 2000 watts for 20 minutes or more, hopefully.
I could also use 400AH L16’s but would have to run them on their side, with two of them on top of the other two with some spacers of some kind. It would be tight. Thoughts?
The other option is to buy lead acid and store outside in an insulated enclosure, and have it close to the wall for short DC cabling. But between cold weather and the inconvenience of it, I’d rather not. If I did, perhaps 6v Rolls 375AH flooded x8 would do the trick? (two parallel strings). Or do I run into not enough panel?
Phase Two Purchase (Late Spring/Early Summer)
-Honda EU3000is connected through 30 amp shore power plug. (will subsist on shore power until tiny house is moved and solar and genset purchased/installed)
-Four 250watt-330 watt panels, totalling 1000-1320 watts, ground mount.
-MPPT Charge Controller 150v. Trying to decide between outback, magnum, and morningstar. Leaning towards morningstar, has no fans, and has ethernet/http hookup for advanced config/monitoring.
-Midnite SPD on combiner box and one inside tiny house for DC.
I am prepared and hoping under ideal conditions for two days of autonomy (light usage) on battery without doing dishes or laundry, which is easy for a single guy.
Any help, thoughts or inputs from the experts would be awesome and much appreciated. I really look forward to hearing from you!
John
Im new to the forum and the world of off grid, and could use some hints and pointers in system selection for a tiny house with space constraints.
Ive picked a few items that I know will fit physically, that are within budget, and should theoretically meet my electricity demands.
Ill start with demands
Tiny House will be stationary and parked permanently next summer, no grid available. 3hrs north of Toronto. Can see -30C in winter. Currently parked in a place where a long 15amp run serves up about 700 watts before voltage drop is too great.
Average calculated KW usage per 24 hrs is expected to be somewhere around 2.0 to 2.5 on battery power. I arrived at this:
-1500watt 6gal water heater. 20 minutes from cold to hot. = 500 watts-ish. One heat cycle per day for shower, well insulated, on a switch. Extravagance = 1000watts
-5 LED lights on, 10w x 5 = 50watts, say 6 hrs a day as a composite = 300 watts
-Efficient 4.5 cu ft AC fridge w/ mechanical t-stat = 600 watts/24hrs
-RV Water pump 80w x 1hr = 80 watts
-Compost toilet fan 2w x 24hrs = 48 watts
-Laptop computer 25 watts x 4hrs = 100 watts
-Radio 10 watts x 5hrs = 50 watts
-LED TV 40 watts x 2 hrs - 80 watts
-Incidentals ie vacuum, coffee grinder, various little battery chargers, water pik, etc. 200 watt hours?
All of the above w/ extravagance showers = 2458 watt hours x1.07 for 93% inverter efficiency = 2630 watts.
I also dont intend to pull much more than 2000 watts continuously off the inverter on battery only, and not for long (20 minutes to get hot water + lights and stuff simultaneously).
The two infrequent appliances Ive listed below I do not intend to run off battery. If its sunny out and I can pull enough juice from the array, then I will use one of the below at a time with the batteries helping out. If its winter and I need clean clothes or laundry, then I will use a generator to stuff amps back in the bank while doing dishes or laundry.
Full 24 Energy efficient new dishwasher
24 Clothes washer
Here’s what I’ve picked to start with…
Phase One Purchase (Very Soon)
Magnum MSH4024M. 24V Mobile Hybrid inverter with load support, 4000 watt 120v, but I don’t need anywhere past 3000 watts at the absolute most w/ load support, extra capacity will be nice for surge. Has automatic neutral-ground switching for shore power or genset.
Appropriate 4/0 cabling, battery monitor w/ shunt, fused w/ disconnect, etc.
Magnum advanced remote
Proper AC disconnects and breakers
AC and DC ground to trailer frame
Midnite Solar SPD wired to shore power and sub panel.
4x Surrette Rolls 6v 335 AH AGM. The spot under the couch only measures 24.5”w, 20.25”D, and 15”H, so these fit nicely. I think they have a C/4 discharge rate? Should support bursts of 2000 watts for 20 minutes or more, hopefully.
I could also use 400AH L16’s but would have to run them on their side, with two of them on top of the other two with some spacers of some kind. It would be tight. Thoughts?
The other option is to buy lead acid and store outside in an insulated enclosure, and have it close to the wall for short DC cabling. But between cold weather and the inconvenience of it, I’d rather not. If I did, perhaps 6v Rolls 375AH flooded x8 would do the trick? (two parallel strings). Or do I run into not enough panel?
Phase Two Purchase (Late Spring/Early Summer)
-Honda EU3000is connected through 30 amp shore power plug. (will subsist on shore power until tiny house is moved and solar and genset purchased/installed)
-Four 250watt-330 watt panels, totalling 1000-1320 watts, ground mount.
-MPPT Charge Controller 150v. Trying to decide between outback, magnum, and morningstar. Leaning towards morningstar, has no fans, and has ethernet/http hookup for advanced config/monitoring.
-Midnite SPD on combiner box and one inside tiny house for DC.
I am prepared and hoping under ideal conditions for two days of autonomy (light usage) on battery without doing dishes or laundry, which is easy for a single guy.
Any help, thoughts or inputs from the experts would be awesome and much appreciated. I really look forward to hearing from you!
John
Comment