Need help with .....lotsa things !

System

Got into solar by interest only (1 panel) ……. which became by need shortly thereafter.
About 80 miles south of Sudbury, Ontario, Canada I found & bought a shack one mile deep in the woods on its own private lake and the rest is history/heaven!
No electricity - unless I paid 27 thousand Canadian dollars for ‘them’ to clear a 60 foot wide swath through the forest, install poles, string wires, transformers, the meter etc. and then ‘they’ own it all as soon as the switch is thrown AND -lucky me- I ‘get’ to pay them EVERY month whether I am there and use any power or not - a price per kilowatt, delivery fee, debt retirement charge, customer account charge, and 2 taxes !!! ……… ummm I don’t think so – for LESS than 10% I can make my own power and feel ten million % better about it……….. sorry I’m ranting – not the correct forum for it…..
Now, I have four 64 watt Unisolar panels 5” off the roof on my homemade aluminum rack at whatever angle the roof is and mostly sorta pointing south, through 4 separate sets of 14 gauge wire to my homemade fused combiner box a max of 14 feet away and down 9 feet to a breaker switched RV charge controller through 12 gauge wire and then through 10 gauge wire to 10 ( free ) paralleled 5 year old used Hawker SBS60 AGM batteries – I get about 1 hour of full sun and another 2 hours of partial shade each day– I use a cheap 500 watt MSW inverter to run seven 11 watt CFL’s, a 12” colour TV, a small stereo and to power the propane fridge controller and it’s light.
I’m only at the cottage 2 of 7 days/week and the meter has NEVER read below 12.00 volts even under max load – we are 2 people so 2 lights only at any one time and it always reads at least 13.4 volts the following weekend when we get there at night.
At the lake (112 ft away) I have a separate 10 watt Unisolar panel hooked to a Sunsaver charge controller and charge two more of the same free batteries for the Shurflo water pump to an 8 gallon bladder tank and up to the cottage for running cold water and thru a Bosch demand propane heater for hot too.
It has all worked great for 3 years now !! – Whether it’s “right” or not – I don’t really know but WAY COOL says I !!!! ........ and what’s next says I ????
Open books, search the internet, read – anything and everything you can about solar and “better gett’er going – ‘cause if you don’t do it yerself, nobody will do it for you”
Got a subscription to HomePower !!! – Great read and lotsa info too !!!
Sooooooo – the new house is next …… To date I have purchased eight 130 watt Kyocera panels, an MX 60 charge controller, an RTS, a Delta 302 lightening arrestor – still need an outdoor combiner box and, and, and ….. bought the ‘brain’ and built a homemade, motorized 2axis tracker for the panels (not installed yet), sunk a 6 foot deep x 18”dia. hole and planted a 14 foot x 6” dia. quarter inch wall pipe in the ground in concrete. My tracker/panel mount location will get sun from 9am until 6pm ALL YEAR LONG – I have sorta watched this for a whole year now – I have not been in a hurry to get this operational yet.
The installed 2” schedule 40 plastic pipe run for the wiring is EXACTLY 157’ (from the combiner box pole mount location, 4 foot down the pipe, 3 foot in the ground, 142 feet along the trench and back up 3 feet, thru the garage wall to the 5 foot high MX60 controller location.
February is the coldest month here …. approx 60 miles North of Toronto, Ontario, Canada……. the coldest it has been this year was -22F at 6am pre sun and up to -12F by 9am in full sun.
I don’t NEED to put in a solar system…… I WANT to…… Our grid power only goes out for about 3 hours at a time in really wicked storms maybe 4 times a year – but then I’m left with no lights or well pump or furnace or sump pump etc when I need them the most.
I figure to set this ‘house’ system up to run the minimum of components during inclement weather and to run whatever I can the rest of the time so it doesn’t sit idle and to reduce my grid dependency.
So now my questions…….. Considering cold temperatures and long wire runs should I have 10 panels - 5 x 2 strings? Or 9 panels ? in 3 strings of 3 or is the 8 panels I have OK in 2 strings of 4 ? What size wire is appropriate - I don’t have an inverter yet - should I go to a 24 or 36 or 48 volt system? ……what size inverter do I need ?? my submersible well pump is 1/2Hp, 5.7 amp @ 220volt and is at 85 feet deep, my propane furnace draws 11 amps at 120 volts, the sump draws 5.2 amps at 120 volts.
Small Hawker AGM 60 amphour batteries are NO PROBLEM AT ALL…… a friend gives me them - as many as I want…. I have literally 100 of them dated from 1997-2004 in my garage sitting on the floor wasting away – (I’ll send pix to whoever doesn’t believe me)……. Is it ok to parallel/series them in as large a qty as I want/need ??? or should I just use these at the cottage and buy some REAL batteries for a house system ??
Sorry to be so wordy but I don’t own a computer and there is no internet access ( except dial-up where I live) and so don’t get to use the internet often - only at the neighbourhood library and I wanted to give out as much info as possible so as to get LOTS of info back, not just questions and laughter at me for what I am trying to do when I don’t ( feel ) I have a clue – I can sort it out then and feel good about my next step.

………Ron

P.S. This forum is the ultimate best !!! I have read almost every post (I think) and have even retained a thing or two…….. at 50 years of age this is quite an accomplishment for me !

mike95490

Re: Need help with .....lotsa things !

Go with as high as voltage as the controller will accept for your cold sunny days (cold days are when the panels put out the most voltage) allow for a cloud at noon, to shade and cool the panels, then the sun breaks thru, and fires up a frosty cold panel. You need to be under your inverters Max Input Voltage.

You need to figure how long your battery runtime will be (4 hour utility blackout ?) and how often the 11A furnace will run, to find out how many amp hours you need to store. Will your pipes freeze inside 4 hours, what if a ice strom takes out power poles for miles, could it take days to get utiliy power back? Thats when you will need the furnace. Get a Kill-A-watt meter and use it to measure several loads, and see what sort of power you will need to run things.

The 220V well pump may be a problem. The sump pump sounds like a critical item - how often does it run? 5 min /hr or 40 min / hr ?, and does it's discharge line need a heater to keep from freezing closed ?

crewzer

Re: Need help with .....lotsa things !

I don’t have an inverter yet - should I go to a 24 or 36 or 48 volt system? ……what size inverter do I need ?? my submersible well pump is 1/2Hp, 5.7 amp @ 220volt and is at 85 feet deep, my propane furnace draws 11 amps at 120 volts, the sump draws 5.2 amps at 120 volts.

Ron,

These loads add up to ~3300 W. So, I recommend you consider an OutBack VFX3648 inverter rated at 48 V (nominal) in and 3600 VA at 120 VAC out. It should be able to handle all of the loads together (its 30 minute surge capacity is 4,000 VA), and it should operate very efficiently (~93%) when running just the furnace or the well pump (~ 1/3 power).

See: http://www.outbackpower.com/pdfs_spec/FX_Domestic.pdf

A very nice feature of this inverter is its “HBX” function. It allows you to run loads from the batteries and use the grid as a backup. You’ll need a Mate, and probably a 4-Port Hub, to enable this feature.

See: http://www.outbackpower.com/pdfs_manuals/Mate%20rev%20230.pdf
and: http://www.outbackpower.com/pdfs_manuals/HUB%20rev%201.1.pdf

I know, I know… the inverter’s output is 120 VAC and you need 220 VAC for the well pump. You can connect an Outback X-240 transformer to the inverter’s output to create an out-of-phase 120 VAC. This plus the inverter’s output will make 240 VAC.

See: http://www.outbackpower.com/pdfs_wiring_diagrams/900-0009-1sht1.pdf

As implied by the inverter, go ahead and build a “48 V” system. If you start out at 24 V, you’ll max out your MX60 at ~1,600 W STC of PV modules. At 48 V, a single MX can handle ~3,200 W STC of PV modules.

Because of your relatively mild summer temperatures, the KC-130’s relatively high Vmp (17.6 V), and your AGM battery bank (doesn’t require an EQ voltage), you could probably get by with wiring your eight PV modules in two series sets of four to make a “48 V” array rated at 70.4 Vmp x 7.39 A Imp x 2 = 1,040 W STC. Should you want to expand the array, you’ll need to add additional PV modules in sets of four.

Alternately, you could buy two additional PV modules and configure your array as two series sets of five modules. The array’s NEC-adjusted low temperature Voc will still be below the MX60 controller’s self-protection cutoff of ~140 V. The higher voltage and/or lower current from a 60 V array would result in less power lost in the long cable run from the array to the controller. However, future array expansion will require new modules in sets of five.

The PV Watts calculator indicates that a 1,300 W STC array mounted on a two-axis tracker located in North Bay, ON, and operating at 67% overall system efficiency (“DC to AC Derate Factor) will generate ~1,900 kWh/yr of energy.

See: http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/

By the way, you’ll need a PV combiner at the array to safely and efficiently connect all of the sub-array series strings into one big array. It looks like you’ll need at least #4 AWG wire and probably #2 AWG wire for the two-conductor run of 157 feet from the combiner to the controller.

See MidNite Solar’s PV Combiner at: http://www.midnitesolar.com/

A good rule of thumb is for the array’s charging current to be ~5% of the battery bank’s capacity. Mid-day output current from the 1,300 W STC array and the MX60 controller in bulk stage to a 48 V battery bank will be ~ 19 A, so an appropriate size battery bank would be ~380 Ah.

Candidate battery bank configurations include eight L16’s (or Rolls/Surrette equivalents) wired in series, or eight size 4D AGM batteries wired in two parallel strings of four batteries per series string. The Hawker SBS60’s are 12 V batteries rated at 51 Ah. You’ll need 28 of ‘em wired in series/ parallel to configure a bank for 48 V x 357 Ah.

How long a 48 V x 380 Ah battery bank will sustain your pumps and furnace fan will depend on how often they’re run, and for how long. The fan draws 120 VAC x 11 A, or 1,320 W net. Through the inverter, that would be ~1,420 W. Assuming the batteries are healthy, fully charged and at a moderate temperature, the bank (~18.6 kWh) could run the fan for ~6.5 hours (or ~11 hours at a 50% duty cycle) before falling to an ~50% state of charge.

HTH,
Jim / crewzer