12 Volt Solar Setup for Garage Only

[SunEagle]

Only idiots would use gasoline. Are you an idiot? Battery cost depending on model and manufactture wil cost you 75-cent to over $1 per Kwh. Not onlyu are you pissing away money but become a very heavy polluter. Not something you would want to brag about or let anyone know you believe.

Well maybe he doesn't care or believe (like some other people here on the forum) that CO2 levels from burning gas is a problem.

[Sunking]

Honda EU2000i Inverter Generator 2000 Watt costs about $1,000, plus $2.50 a gallon of gasoline per 9 hrs of use,.

Only idiots would use gasoline. Are you an idiot? Battery cost depending on model and manufactture wil cost you 75-cent to over $1 per Kwh. Not onlyu are you pissing away money but become a very heavy polluter. Not something you would want to brag about or let anyone know you believe.

[Sunking]

Well, it does has to do with it a lot. It makes a lot of sense to have even a couple of batteries fully charged at 2.7 kWh. I can have lights, AM/FM radio and TV until next day when the sun shines again. The sun will shine for 7 billion more years. Trillions of trillions of mega watts of power there for free!

Stop that silly, you are delusional. No solar needed or required. Just a battery charger. Solar is very far from free, you must live near the Left Coast Island of Austin where they teach non sense. Battery cost alone will cost you 5 to 10 rimes more than buying from the Power Company and the Power company is a lot more environmentally friendly than a battery manufacture. Your POCO will generate a lot less pollution and not waste as much fuel and resources your children will never see. Austin will not teach you that.

[SunEagle]

Honda EU2000i Inverter Generator 2000 Watt costs about $1,000, plus $2.50 a gallon of gasoline per 9 hrs of use, plus the noise. ha, ha, ha.
That's $0.28 per kWh plus $28 per month for 36 months. If you are lucky to find gasoline when the emergency hits.

I agree that the Honda would be my first choice as a quite emergency backup power source. I also have a little bit of gas available in case of an outage so no worry about the lack of fuel.

But I also get to thinking that I have to worry about the exhaust fumes and there is still some noise even at 50 db.

I have both a quite Coleman 1800 watt generator as well as my 65Ah battery system for my CPAP both are easy to setup and will last the night. It is a matter of choice.

[john95]

Honda EU2000i Inverter Generator 2000 Watt costs about $1,000, plus $2.50 a gallon of gasoline per 9 hrs of use, plus the noise. ha, ha, ha.
That's $0.28 per kWh plus $28 per month for 36 months. If you are lucky to find gasoline when the emergency hits.

[J.P.M.]

It still comes down to what is less costly. Power from a solar/battery system is still much more expensive then from the grid. And unless the cost for fuel goes up again is more expensive then getting it from a generator. But at least it can be less noisy.

On the noise, I wonder a bit if it might be more practical and perhaps more cost effective, at least in some cases, if instead of PV with the costs, including that of commonly used batteries as a means of supplying off grid power on a reasonably reliable basis, to simply get a quality ICE powered electric generator and place it in an appropriate, very well sound insulated and appropriately well ventilated and designed enclosure fit for that purpose. Then, compare the life cycle costs of the two alternatives.

I suspect that, while the design and construction costs of such an enclosure would not be cheap, such a sound control method may well be a way to address most, if not quite all of the noise concerns in a way that would be more cost effective over a life cycle of say, "X" years, having a life cycle cost that is less than that of current life cycle cost of the PV/battery alternative when all things are considered, including perhaps some assignment of some monetary equivalent to the various not so desirable aspects for each alternative based on the opinions of the owner/user.

[SunEagle]

Well, it does has to do with it a lot. It makes a lot of sense to have even a couple of batteries fully charged at 2.7 kWh. I can have lights, AM/FM radio and TV until next day when the sun shines again. The sun will shine for 7 billion more years. Trillions of trillions of mega watts of power there for free!
About the wife and kids, you do make them reliable by taking the money and toys away. My son begs me to do any chores around the house when I lock the internet connection.

It still comes down to what is less costly. Power from a solar/battery system is still much more expensive then from the grid. And unless the cost for fuel goes up again is more expensive then getting it from a generator. But at least it can be less noisy.

[john95]

So what does that have to do with Solar? You do not need expensive limited solar to have power when commercial power is out. Pros do not use solar when power is out. It cost to much, supply strictly limited, very unreliable and cannot be counted upon when needed. Much like your wife and kids.

Well, it does has to do with it a lot. It makes a lot of sense to have even a couple of batteries fully charged at 2.7 kWh. I can have lights, AM/FM radio and TV until next day when the sun shines again. The sun will shine for 7 billion more years. Trillions of trillions of mega watts of power there for free!
About the wife and kids, you do make them reliable by taking the money and toys away. My son begs me to do any chores around the house when I lock the internet connection.

[Sunking]

In case of an emergency, I want to have some electricity. It is always good to have electricity at the middle of the night when all goes dark.

So what does that have to do with Solar? You do not need expensive limited solar to have power when commercial power is out. Pros do not use solar when power is out. It cost to much, supply strictly limited, very unreliable and cannot be counted upon when needed. Much like your wife and kids.

[john95]

Due to potential losses and limited sunlight the 300 watts and an MPPT CC would be better IMO as long as you can wire them in series and do not exceed the max DC input voltage rating of the CC.

Remember that C/10 is the sweet spot for charging but you can go to C/8 if needed, which at 25 amps is still only a C/9.

Thanks for you info SunEagle! You are the man!
In case of an emergency, I want to have some electricity. It is always good to have electricity at the middle of the night when all goes dark.

[SunEagle]

Updated Components for my garage Small Solar 12 volt Project 1.3 kWh Max usage:

1x Renogy 100 Watt 12 Volt Polycrystalline Solar Panel 122.99
1x Hightech Solar 160 watt 12 volt Monocrystalline Solar panel $165.00
2x TROJAN T105 6 VOLT 225 AH $240.00 (2.7 kWh Storage)
1x HQST 40A MPPT Solar Charge Controller $153.00
1x AIMS 600 Watts Pure Sine Inverter $129.00

Total of $809.00

If I go with the 3x 100 watts panels is more money and I get out of the charging requirement of 22.5 A
260 watts = 21.66 A and 300 watts = 25 A.
So, I'm closer to the 22.5 requirement with 260 Watts than with 300 watts. But I may get only 270 watts with the 300 watts panels due to other factors.

Should I get the 3x 300 watts panels better?

Due to potential losses and limited sunlight the 300 watts and an MPPT CC would be better IMO as long as you can wire them in series and do not exceed the max DC input voltage rating of the CC.

Remember that C/10 is the sweet spot for charging but you can go to C/8 if needed, which at 25 amps is still only a C/9.

[john95]

Let's do some simple calculations assuming that all these components last 36 months working fine, $809/36=22.47 per month:

1.3 kWh x 30 days=39
22.47/39= 0.57 per kWh
Still way more expensive than my POCO.

These components must have last 10 years to come down to $0.17 per kWh, just 0.03 under my POCO price per kWh
And of course just the solar panels may last more that 10 years; the other stuff will have to be replaced many times to go more than 10 years.

[john95]

Updated Components for my garage Small Solar 12 volt Project 1.3 kWh Max usage:

1x Renogy 100 Watt 12 Volt Polycrystalline Solar Panel 122.99
1x Hightech Solar 160 watt 12 volt Monocrystalline Solar panel $165.00
2x TROJAN T105 6 VOLT 225 AH $240.00 (2.7 kWh Storage)
1x HQST 40A MPPT Solar Charge Controller $153.00
1x AIMS 600 Watts Pure Sine Inverter $129.00

Total of $809.00

If I go with the 3x 100 watts panels is more money and I get out of the charging requirement of 22.5 A
260 watts = 21.66 A and 300 watts = 25 A.
So, I'm closer to the 22.5 requirement with 260 Watts than with 300 watts. But I may get only 270 watts with the 300 watts panels due to other factors.

Should I get the 3x 300 watts panels better?

[SunEagle]

It is very simple then. I thought you were telling me that I needed 27x 100 watts solar panels to achieve the charging per hour requirement of full 225 AH of my batteries. Now I know is only a portion of the whole 225 AH rated battery. Putting in more simple terms, one needs 10% per hour of charging power of the total rated battery AH. To get to exact figures is darn hard!

In my situation according to you:
To get the C/10 charge requirement all I have to do is divide 225/10=22.5 which is the charging requirement.
22.5 AH is 270 watts. Where am I going to get 1x 270 watt 12 volts solar panel? If I get 3x 100 it goes over the 270 watts. Sure I can always get 1x 100 watt panel and 1x 160 watt panel for a total of 260 watts, but it will not get the exact charging requirement. I see that some are monocrystalline and others are polycristalline. Can they even be mixed? or I have to use the same kind?

How do they come to this requirement of C/8 and C/12?

Just remember a PWM CC works as Amps in = Amps out. While a MPPT CC works as Watts in = Watts out which is more efficient.

You would usually wire panels to a PWM CC in parallel so the Imp of each panels is added up but the wire size has to be larger due to the higher amps.

A MPPT CC allows you to wire the panels in series which keeps the wire size down yet you get the full wattage used converted to charging amps.

As for the type of solar panel. You can mix a mono cell with a poly type. Just make sure the Vmp is within 5% of each other or they might fight.

[john95]

Whatever system you build remember that if you use FLA batteries they need to be charged at a rate between C/8 and C/12 where C = the AH rating of the system. Quick rule of thumb is C/10 or just divide the Ah by 10 and then you can calculate the amount of solar pv wattage to get the charging amps.

If you get too many amps you can fry the batteries. Too little and their plates can sulfate and reduce the amount that can charge.

It is very simple then. I thought you were telling me that I needed 27x 100 watts solar panels to achieve the charging per hour requirement of full 225 AH of my batteries. Now I know is only a portion of the whole 225 AH rated battery. Putting in more simple terms, one needs 10% per hour of charging power of the total rated battery AH. To get to exact figures is darn hard!

In my situation according to you:
To get the C/10 charge requirement all I have to do is divide 225/10=22.5 which is the charging requirement.
22.5 AH is 270 watts. Where am I going to get 1x 270 watt 12 volts solar panel? If I get 3x 100 it goes over the 270 watts. Sure I can always get 1x 100 watt panel and 1x 160 watt panel for a total of 260 watts, but it will not get the exact charging requirement. I see that some are monocrystalline and others are polycristalline. Can they even be mixed? or I have to use the same kind?

How do they come to this requirement of C/8 and C/12?