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Been reading the threads here during my downtime and slowly trying to figure this all out. For some reason I decided to buy panels before planning anything else out /facepalm. So the panels are 24v and I plan on buying a 2500 watt ( 5000watt peak) 12V inverter. Do I need to add more wattage (either more panels or wind turbine) to generate closer to the 2500 watts the inverter is made for? Can anyone recommend a good MPPT charge controller that would fit my system and also a good number batteries I should be looking to purchasing (will most likely get cheapo golf cart or deep cycle batteries until I optimize my system). Any tips would be greatly appreciated!
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First thing to do is forget about 12 volt toys. That would be very foolish like your plan so far.
At the power levels you have spoke of so far demands a minimum of 24 volt battery. But the real problem is your location is not solar friendly. A better plan would be a change of address about 2000 miles south west.
With your 1800 watts of panels in your location using a 80 amp MPPT controller on a 24 volt battery will only generate about 1 Kwh per day or 10 cents worth of electricity. If you were to run that 2000 watt inverter near full power is about 20 to 30 minutes worth of power per day.
So how is your plan working out so far?MSEE, PE -
Hey Saskatchewan gets the most sun of any province in Canada lol. My biggest power concerns are having ample power for A/C for the summer which I thought would go perfectly with a solar system. Wood would be my heating source along with propane which will also be used for my fridge and other big appliances. So I just wanted to use my electricity for a computer, tv and lighting (along with A/C in the summer). Should I just scrap my plans and cut my losses? It's just I see someone down my road (rural area) is running off grid, with some panels and a couple small wind turbines and a big propane tank.First thing to do is forget about 12 volt toys. That would be very foolish like your plan so far. At the power levels you have spoke of so far demands a minimum of 24 volt battery. But the real problem is your location is not solar friendly. A better plan would be a change of address about 2000 miles south west.
With your 1800 watts of panels in your location using a 80 amp MPPT controller on a 24 volt battery will only generate about 1 Kwh per day or 10 cents worth of. If you were to run that 2000 watt inverter near full power is about 20 to 30 minutes worth of power per day.
So how is your plan working out so far?Comment
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My panels are coming in today and I was going to wait to post but was getting antsy. I am planning on converting shipping containers into a place to live on land I just purchased in the country and I want to be off grid, that is why I want to do the solar/propane/wood combo.
So would it work if i added a couple wind turbines, a MPPT with the specs you mentioned and the same inverter?
I thought Saskatchewan would be good for solar with the brutal summer months (june-sept) having sun from 5am-10pm
I also put in my postal code to some website and it said that this place is solar power friendly with just being 1 spot below the top of the scale.Comment
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OK let's run with that idea and work the numbers. Let's say you live in Regina the southern most city. From Last of May to the first September you receive 5 Sun Hours on average. Let's say you have a 3-ton AC unit with an excellent SEER rating of 14 and with your cool summers only runs 6 hours per day. Fair enough? That unit would use 15.5 Kwh per day. In Canada you pay roughly 9-cents per Kwh so to run the AC unit will cost you 15.5 Kwh x $0.08 = $1.25 per day to run using commercial power.
OK to generate 15.5 Kwh per day in your area with off-grid solar battery will require:
- Solar panel Wattage = 4700 watts = roughly $9300
- 1 80 Amp MPPT Controller = $900
- Battery Capacity = 77.5 Kwh @ 48 volts @ 1600 AH weighs 5000 pounds and cost $12,000 for a 5 year battery, or a cheap 2 year battery @ $7000
- 5 KW industrial Grade True Sine Wave Inverter @ 48 Volts = $7000
- Misc hardware and materials to make it all work = $5000
- Labor and permits not included.
- Total estimated equipment cost = $33,390 for the 5 year battery, and $28,900 for the 2 year battery + Labor and Permits.
Now I will give you the fact you can use the system year round and the system has to potential to generate 4,500 Kwh per year or 22,500 Kwh in 5 years before you need a battery replacement cost of more than $12,000. So in the first 5 years you go from paying to the greedy POCO 8-cents per Kwh, to paying your friendly green merchant dealer $1.51 per Kwh or a 1800% increase in electricity cost. A 5 year battery alone will cost you $0.53/Kwh, and a cheap 2 year battery will cost you $0.77/Kwh
So please let me be your friendly Green Merchant Dealer and we will both be tickled Pink and stick it to the MAN at the POCO. Let's go with the cheap 2 year battery plan.
MSEE, PEComment
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wow thanks for the break down. that battery number wasn't what I expected...guess i'll be going with a swamp cooler.OK let's run with that idea and work the numbers. Let's say you live in Regina the southern most city. From Last of May to the first September you receive 5 Sun Hours on average. Let's say you have a 3-ton AC unit with an excellent SEER rating of 14 and with your cool summers only runs 6 hours per day. Fair enough? That unit would use 15.5 Kwh per day. In Canada you pay roughly 9-cents per Kwh so to run the AC unit will cost you 15.5 Kwh x $0.08 = $1.25 per day to run using commercial power.
OK to generate 15.5 Kwh per day in your area with off-grid solar battery will require:
- Solar panel Wattage = 4700 watts = roughly $9300
- 1 80 Amp MPPT Controller = $900
- Battery Capacity = 77.5 Kwh @ 48 volts @ 1600 AH weighs 5000 pounds and cost $12,000 for a 5 year battery, or a cheap 2 year battery @ $7000
- 5 KW industrial Grade True Sine Wave Inverter @ 48 Volts = $7000
- Misc hardware and materials to make it all work = $5000
- Labor and permits not included.
- Total estimated equipment cost = $33,390 for the 5 year battery, and $28,900 for the 2 year battery + Labor and Permits.
Now I will give you the fact you can use the system year round and the system has to potential to generate 4,500 Kwh per year or 22,500 Kwh in 5 years before you need a battery replacement cost of more than $12,000. So in the first 5 years you go from paying to the greedy POCO 8-cents per Kwh, to paying your friendly green merchant dealer $1.51 per Kwh or a 1800% increase in electricity cost. A 5 year battery alone will cost you $0.53/Kwh, and a cheap 2 year battery will cost you $0.77/Kwh
So please let me be your friendly Green Merchant Dealer and we will both be tickled Pink and stick it to the MAN at the POCO. Let's go with the cheap 2 year battery plan.
The reason I looked into solar is b/c of the DIY aspect, I'm not trying to stick it to any one or give all my money to the local green merchant dealer. I'm just trying to save money and to set up a simple 1800 watt solar system. To bring electricity to my place will be around $15000. I bought the panels b/c is was 99cent a watt so I thought i got a decent deal on 99/watt for a small 8 panel purchase. SO Say I just want to run LED lights, my macbook, and some fans. Wouldn't 1800 watts be enough for that? Maybe I should just go talk to my neighbour and copy his set up, b/c somehow he is lives off grid.
PS not sure if you were kidding, but Summers here are pretty harsh @ +30 degrees celsiusComment
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Well the batteries will stil be a major expense, but I can tell you about how much power you can generate in Summer and Winter. But let's get the battery out of the way first. Flooded lead acid batteries can only a maximum C/8 charge rate where C = the 20 hour Amp Hour rating of the battery. So the minimum size battery you can hang on a 1800 watt panels is 600 Amp Hours @ 24 volts. AGM batteries can take up to C/4 and the minimum AGM is 300 Amp Hours. But here is the catch AGM's cost 2 times of much as flooded lead acid. So for the most bang for your buck use FLA as 600 AH is twice the capacity of 300 AH. As for cost on batteries you are looking at $1200 on the low end 2-year battery and $2200 on the high end for a 5 year battery.
OK with 1800 watts of solar panels the minimum battery voltage you can run is 24 volts because of the current limitations of the charge controllers. The largest MPPT charge controller you can get today is 80 amps. With 1800 watts on a 24 volt system delivers 75 amps. To try to run at 12 volts would be 150 amps requiring 2 very expensive 80 amp charge controllers. So your only choices are 24, 48, and 60 volt batteries. 12 is out of the question. So if you go with 24 volts you will be near your 2000 watt input limit. However down the road you can convert to 48 volts and have a limit of 4000 watts input.
OK enough Blather. A 1800 watt battery system in your area will generate roughly 4.7 Kwh per day of useful power. You have to figure out what you can do with it. So yes you can run a lot of lights, Mac Book, and fans. I would suggest Swamp Cooler because you will have enough power for that, but I think the humidity is too high in your area?
No not really. I live in Texas and 30 degrees Celsius here is time to break out the long sleeve shirts and jackets. Today it was 42 here in TX and been that way everyday for the last couple of months and will last late into September. I guess I shouldn't complain because compared to last Summer, this one is a cool breeze.MSEE, PEComment
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I live off grid, if I could get grid power connected for $15000 I would jump at the chance.To bring electricity to my place will be around $15000.Comment
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Hmm well that was just something my new neighbour mentioned but i'm not sure how accurate that number is. I'll look into it, but in the mean time I will continue with my small solar set up, it will be handy if I decide to build a cabin at the end of my property far away from the road anyways. thanks for all the in depth tips. sunkingComment
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Also just to clarify. With my panels, I can get a 80 amp outback controller, wire 12V batteries to 24V, and use a 12v inverter? thanksComment
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Johnny you need to give up the 12 volt idea. 12 volts is for toys and RV's.
With 1800 watts of solar panels if you insist on 12 volts is going to require two very expensive 80 amp charge controllers, and a whole lot of very expensive large diameter copper wire to handle all that current. The maximum panel wattage input on a 80 Amp MPPT controller is:
1000 watts @ 12 volt battery
2000 watts @ 24 volt battery
4000 watts @ 48 volt battery.
So give up the 12 volt idea. With 1800 watts the minimum is 24 volts, but at 1800 watts you just as well go 48 volts so you can easily expand later. Your inverter will have to match the battery voltage. At 1800 watts panel wattage the minimum battery size is going to be
600 AH @ 24 volts
300 AH @ 48 volts
Maximum Inverter wattage with minimum battery size is 1800 wattsMSEE, PEComment
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Oh ok thanks. I thought the MPPT controller was for converting to 12 volt. So I can keep lighting DC and the rest of my stuff 48 v AC? Like where do I even get 48 volt stuff, what about computer/cell phone chargers?Comment
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hiyas
I did my own computerizations
according to my elect bill live in TX here.. our AC went out and the last 24 hrs we used about 15kwh of elec, normally use about 30 - 43/day. that means our AC unit runs at about 3300 watts. so a 5000 watt inverter should handle most of your needs. Mind you we live in TX hot hot hot! in summer. wow 240kwh per month on my elec bill would be great but I hate the heat
the 1800 watts of panels you bought should cover everything but your AC unit. also another thing you can do is change every light in your house to the energy savers you know the 24 watt lights that run like a 100 watt bulb. they really make a difference and last a good while.
you might also want to be concernd that 48 volt systems can get rather expensive.Comment
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Wrong, wrong, wrong, dead wrong. You made a huge flaw. Your AC unit uses a lot more than 3300 watts and a 5000 watt battery inverter would shut down immediately when you AC unit starts up.
MSEE, PEComment
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