Planning to reduce electric bill by solar push, no feed back to grid. Daylight hours only.

[Q-Dog]

I spent 30 years working in television and movies. I can't watch internet videos for more than a couple of minutes.

 

[roadrunner]

You know what would work? As many watts in panels as you can fit, a DC charge controller to match, 2 to 4 golf cart batteries, and a DC to AC inverter of appropriate size. With more solar watts than your cooler needs to run, you can put some charge back into the batteries during the day. And you can run the cooler off the system for a while after the sun sets. Run a new outlet from the inverter to sit next to the outlet you use for the cooler so you can use grid if your battery runs down too far.

If you size it well you could run the cooler off of the battery 100% of the time. And you wouldn't have to worry about the power company at all.

exactly what i was going to do from the start, run an 120 volt cord from the inverter in shed to my cooler on outside of my trailer, so i can have the solar 120volt,from inverter,coming right next to cooler, so solar and grid right next to one another. using the extension cord as 120 volt instead of wire from the panels so i can use smaller wire instead of running 40 feet of dc wiring.

 

[fafrd]

thats what Will is doing in his video i posted running a heat gun at 650 watts of of a battle born 100ah 12 volt battery, and it doesnt back feed, of course the battery may not last long being just 1 at 12 volt. thats where i got the idea, has anyone watched his vid i posted.

Yes, I watched the entire video. That’s why I told you a Hybrid Inverter is not the best choice for your application because:

-it costs more for stuff you don’t need (like an AC charger).

-it doesn’t back-feed because it has a transfer-switch (which also costs more $$$s and is not needed if you plan to only power a single appliance for as long as the sun and/or battery lasts).

The $85 grid-tied inverter is a much wiser investment for your needs (and the $275 GTIL inverter by the same supplier is a better choice than the $400 all-in-one Will discusses in that video).

thats the whole reason i came to his forum because he wont answweer comments from or on his videos, even though hes making money off of youtube because we watch his videos.

And hopefully you’re glad you did!

 

[roadrunner]

Ill see if Will even will answer a question about one of his videos, without trying to charge me his consultation fee since hes the one that posted it.

 

[roadrunner]

Yes, I watched the entire video. That’s why I told you a Hybrid Inverter is not the best choice for your application because:

-it costs more for stuff you don’t need (like an AC charger).

-it doesn’t back-feed because it has a transfer-switch (which also costs more $$$s and is not needed if you plan to only power a single appliance for as long as the sun and/or battery lasts).

The $85 grid-tied inverter is a much wiser investment for your needs (and the $275 GTIL inverter by the same supplier is a better choice than the $400 all-in-one Will discusses in that video).



And hopefully you’re glad you did!

i saved the inverter you pointed to me in my watch list on amazon so i can find it easier, and thanks for your help, this forum is a great resource to know about now, i never have even heard of it before.

 

[roadrunner]

but, if i have the ac charger in that inveretr i could charge the single battery at the same time im running my swamp cooler so my battery would always be charged while running, now if will would answer my couple questions i wouldn't have to be here

 

[fafrd]

exactly what i was going to do from the start, run an 120 volt cord from the inverter in shed to my cooler on outside of my trailer, so i can have the solar 120volt,from inverter,coming right next to cooler, so solar and grid right next to one another. using the extension cord as 120 volt instead of wire from the panels so i can use smaller wire instead of running 40 feet of dc wiring.

That will work as long as you don’t mind unplugging from your solar extension cord and plugging into grid power whenever the battery runs dry.

Also, if you go that route, you do not want a grid-tied inverter (because there will be no grid signal reaching the inverter).

With the GTIL inverter, you would need to run an extension cord from the cooler to the shed, place the clamp sensor on the hot leg of that extension cord (or make an adapter like an electrical outlet) and then run a second extension cord from that point back to the grid.

This way, your cooler will always have power and as much of that power as possible will come from solar during the day.

If you have more daytime power than you can use, you can add a battery and a charge controller and then the cooler will also run as late into the night as the battery allows.

In either case, either when the sun has gone down (without battery) or when the battery is drained, the cooler will continue to run off of grid power without you needing to unplug/reply it.

 

[roadrunner]

my understanding is volts equals the measurement of electricity, wattts and amps is the power of electricity and its how much current flows and is what your are charged for, so if i use half the amps of a device or watts i am using half of the electricity.so my electric bill would be cut in half if im using half of normal.

 

[fafrd]

but, if i have the ac charger in that inveretr i could charge the single battery at the same time im running my swamp cooler so my battery would always be charged while running, now if will would answer my couple questions i wouldn't have to be here

As I explained, charging a battery from grid power will not save you money, it will cost you money.

The AC battery chargers are ~80% efficient. And the inverters are also ~80% efficient.

So if you want to power your 400W cooler for an hour through an inverter, you will need 400Wh / 80% = 500Wh of battery energy.

And if you want an AC charger to store 500Wh of energy in your battery, it will consume 500Wh / 80% = 625Wh to do so.

So you will pay the power company for 625W to run for one hour instead of only paying them for 400W if you just ran your cooler directly off of the grid (156% energy cost).

The only reason for the AC charger is for backup power during a power outage (which is not your primary concern). If you are worried about being able to run your cooler when the grid goes down, you always want to be certain your battery is full even if it is cloudy and there is no solar production. So you can charge from grid to be prepared for a power outage. Needs a much bigger battery, costs more money, and has nothing to do with the concerns you’ve listed for us.

 

[roadrunner]

That will work as long as you don’t mind unplugging from your solar extension cord and plugging into grid power whenever the battery runs dry.

Also, if you go that route, you do not want a grid-tied inverter (because there will be no grid signal reaching the inverter).

With the GTIL inverter, you would need to run an extension cord from the cooler to the shed, place the clamp sensor on the hot leg of that extension cord (or make an adapter like an electrical outlet) and then run a second extension cord from that point back to the grid.

This way, your cooler will always have power and as much of that power as possible will come from solar during the day.

If you have more daytime power than you can use, you can add a battery and a charge controller and then the cooler will also run as late into the night as the battery allows.

In either case, either when the sun has gone down (without battery) or when the battery is drained, the cooler will continue to run off of grid power without you needing to unplug/reply it.

exactly, i can run the wire in through the window just like i have my cooler wiring run right now, i have the cooler wiring from the cooler comes to a cooler rotary swith on my wall, in a electrical box mounted to wall by my window,and the cord is attache to the outlet by a short cord plugged into the wall outlet, 120 volt of course. the wire is run though a piece of plywood on side of cooler. i could have the `120 volt from inverter wire come in through same plywood piece, this way both plugs can be right next to one another and no reason to go outside
This sounds like a solution that could work especially if i can 2 o r3 panels over 200 watt per panel, i could fit 3x60 cell panels

 

[roadrunner]

As I explained, charging a battery from grid power will not save you money, it will cost you money.

The AC battery chargers are ~80% efficient. And the inverters are also ~80% efficient.

So if you want to power your 400W cooler for an hour through an inverter, you will need 400Wh / 80% = 500Wh of battery energy.

And if you want an AC charger to store 500Wh of energy in your battery, it will consume 500Wh / 80% = 625Wh to do so.

So you will pay the power company for 625W to run for one hour instead of only paying them for 400W if you just ran your cooler directly off of the grid (156% energy cost).

The only reason for the AC charger is for backup power during a power outage (which is not your primary concern). If you are worried about being able to run your cooler when the grid goes down, you always want to be certain your battery is full even if it is cloudy and there is no solar production. So you can charge from grid to be prepared for a power outage. Needs a much bigger battery, costs more money, and has nothing to do with the concerns you’ve listed for us.

ok, but if i put up say 3x 250 watt panels, i could charge battery from excess im not using above the 400 watt.

 

[Forbisher]

my understanding is volts equals the measurement of electricity, wattts and amps is the power of electricity and its how much current flows and is what your are charged for, so if i use half the amps of a device or watts i am using half of the electricity.so my electric bill would be cut in half if im using half of normal.

Incorrect.
You get charged for watt hours not volts.
Volts x Amps = Watts.
Half the Amps but twice the Voltage so you are using the same watts.

120V x 10A = 1200 SAME watts
240V x 5A = 1200 SAME watts

 

[Bud Martin]

my understanding is volts equals the measurement of electricity, wattts and amps is the power of electricity and its how much current flows and is what your are charged for, so if i use half the amps of a device or watts i am using half of the electricity.so my electric bill would be cut in half if im using half of normal.

Do the math, you half the current but you double the Voltage, what is the Wattage will be? or you half the Voltage but double the Amp, what Wattage do you get?
Utility charges you how WATTS you use.

 

[fafrd]

ok, but if i put up say 3x 250 watt panels, i could charge battery from excess im not using above the 400 watt.

Yes, but to charge a battery from excess solar production you want a DC Solar Charge Controller (SCC), not an AC battery charger.

Will’s inverter does not include a solar charge controller - it only charges from AC.

If you had 3x750W panels and want to charge a 24V battery from solar, you need a 30A MPPT solar charger controller like this;

https://www.amazon.com/EPEVER-Charge-Controller-Display-Switch/dp/B075XHCT5K

The 600W inverter you found for $85 can run off of either solar panels or battery, do that inverter, a 30A SCC similar to the one I linked to here, and 3 60-cell panels would give you a full system.

And it’ll save you more if you can afford larger panels and a higher-capacity battery.

3x350W panels should allow you to power all day and store enough energy to power most of the night. You’d need a 40A SCC instead of 30A and a 24V battery with ~5kWh of capacity.

 

[roadrunner]

i turn my cooler off at about 9 or 10 oclock anyway. sun doesnt go down until 830 or 9 here
of course its low in the sky so panels wont produce much at all

Incorrect.
You get charged for watt hours not volts.
Volts x Amps = Watts.
Half the Amps but twice the Voltage so you are using the same watts.

120V x 10A = 1200 SAME watts
240V x 5A = 1200 SAME watts

ok, your right, i just re read about it, been over a year since my surgery and havent worked

 

[roadrunner]

Yes, but to charge a battery from excess solar production you want a DC Solar Charge Controller (SCC), not an AC battery charger.

Will’s inverter does not include a solar charge controller - it only charges from AC.

If you had 3x750W panels and want to charge a 24V battery from solar, you need a 30A MPPT solar charger controller like this;

https://www.amazon.com/EPEVER-Charge-Controller-Display-Switch/dp/B075XHCT5K

The 600W inverter you found for $85 can run off of either solar panels or battery, do that inverter, a 30A SCC similar to the one I linked to here, and 3 60-cell panels would give you a full system.

And it’ll save you more if you can afford larger panels and a higher-capacity battery.

3x350W panels should allow you to power all day and store enough energy to power most of the night. You’d need a 40A SCC instead of 30A and a 24V battery with ~5kWh of capacity.

ok, now this sounds like the beginning of a plan, thanks, so now to see what other panels i can get a hold of, im looking but if i use the inverter i picked up, any extra would back-feed then right.

 

[fafrd]

ok, now this sounds like the beginning of a plan, thanks, so now to see what other panels i can get a hold of

I always get my panels first.

Deals come and go, so if you know what pricing (in terms of $/W) represents a ‘deal’ and you know the approximate range of panel sizes you are interested in, you’re in position to jump when the right deal comes along.

I knew I wanted 3 panels in the 350-400W range so when my local supplier put 380W panels on sale for $0.39/W ($148.20 each), I pounced.

Now that I’ve got specific panels to connect, I can start shopping for the best charge controller.

Everything else (inverters, SCCs) is pretty much commoditized, but panel prices swing wildly based on which specific panels are in excess supply...

 

[roadrunner]

thats what i will do is starty checking panel prices and talk to a guy i know that works for a solar company, hes the one that can sell me 230 watt panels, brand new for $100 last time i talked to him, if they have any left laying around. i have to wait until i get my stimulus checks anyway. so first things first i guess, at least i have the charge controllers and inverters saved in my list on amazon so i will always have that info

 

[roadrunner]

the only thing right now on craigslist is 315 watt panel, brand new, REC is brand, have to check on that. for $175, .55 cents a watt

 

[fafrd]

thats what i will do is starty checking panel prices and talk to a guy i know that works for a solar company, hes the one that can sell me 230 watt panels, brand new for $100 last time i talked to him, if they have any left laying around. i have to wait until i get my stimulus checks anyway. so first things first i guess, at least i have the charge controllers and inverters saved in my list on amazon so i will always have that info

Knowing an installer who can sell you excess panels at a good price is a good starting point, but make sure they come with warranty.

And also, check what panel sizes they are using now for new projects - you’ll be happier with 2x280W or 2x300W rather than 3x230W...

You will also often find adds on Craigslist by installers looking to unload excess panels.