Freezer off of Solar panels

[Mwashere]

Hello all,

I hope all is well.
I’m starting out trying to figure how to run this freezer nameplate off of solar panels. Can anybody help me how to calculate how many solar panels I need and how many batteries I need?

I much appreciate all your help or any tips you can give me. Thank you so much.

 

[DIYrich]

To start the freezer, you need 8.6 amps at 115v, or roughly 1kw. You will need an inverter capable of 1kw, panels to charge a battery, and enough battery to run it as long as you want.

 

[Mwashere]

To start the freezer, you need 8.6 amps at 115v, or roughly 1kw. You will need an inverter capable of 1kw, panels to charge a battery, and enough battery to run it as long as you want.

Thank you so much, so I figured this freezer doesn’t all the time run 8.6A, I assume hits that 8.6 when the motor kicks in. Roughly how many batteries and panels would I need if I wanted to run all day?

 

[DIYrich]

Thank you so much, so I figured this freezer doesn’t all the time run 8.6A, I assume hits that 8.6 when the motor kicks in. Roughly how many batteries and panels would I need if I wanted to run all day?

Don't know. How big is it? How often do you open it? In the house, basement, garage, ???

All this factors into kwh per day.

Backup power for cloudy days?

Could be 1 kWh per day. Need another 1kWh for the inverter. One 400 watt panel could produce 2kwh on a good day. One 5kwh battery would work. Just a guess.

 

[wiseacre]

Use a Kill A Watt monitor to get your daily usage
https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor

 

[E. Cho]

Until you get a Killawatt type meter, you could check the label on your freezer that lists it's specs. It might be on the back or even near the compressor. Every appliance these days has one. It may list the running watts or amps and or the maximum used watts or amps at whatever the appliance voltage is. Or you could check the manufacturer website for the specs of your exact model or one similar to it. And you could then time the cycles over a one hour period. This won't tell you the starting surge required, usually 3-5+ x the running watts, but it will give you a starting point. Then just do the math so you have more solar and or battery watts than appliance watts, especially to cover the compressor starting surge. The $20+ killawatt meter should have a Max watt measure, which will be close to the real start surge. Not all of these types of watt meters capture or record that.

 

[MichaelK]

Is this your freezer?


Looking at comparable models at HomeDepot, I'd guestimate your unit might consume between 1.6 and 1.8kWh of power per day. But, as E.Cho mentions, the best option is using the killawatt to actually determine your real-world consumption. But, we can start with the 1.8kWh value and work with that till you have better real-world numbers.

Let's assume you have to run this unit on standard 120V 60Hz AC. The inverter just being on, whether or not the freezer is actually running, will also consume power. That varies from inverter to inverter, but let's say it's 1000Wh per day. So, to keep the freezer on 24/7 you need 1.8kWh + 1.0kWh = 2.8kWh of power. Let's round that to 3.0.

1000W at startup is a bit large for a 1000W inverter, so you want to look at one that can handle 2000W. You really never want to run your equipment at the ragged upper edge of their specifications.

You're in Texas, so you're in a solar-rich area. Let's assume you get about 6 sunhours (sh) per day in June and 3 sh in December. Go with the lowest number, never the highest. Assuming you need 3000Wh of power each and every day, and you get 3 sunhours of solar in December, you need 3000Wh/3 sh =1000W of panels. At 12V, that would be a substantial number of amps, so you are better off with a 24V system, that is a 24V battery bank, powering a 24V inverter.

Assuming at startup you are consuming 1000W, from a 24V battery bank that would be ~ 42Amps. Look at getting 400Ah lead-acid batteries, or maybe 200Ah of Li batteries to support that level of battery drain.

Keep in mind that these are numbers that I came up with, not YOUR numbers. I suspect that this is a commercial-grade unit that consumes more than a domestic HomeDepot model, so plan on these numbers as the bare minimum of what will be needed.

So, minimally, you'll need....
1000W of panels, say four 250W residential panels
40+amp charge controller
2000W 24V sine-wave inverter
200-400Ah batteries

 

[wpns]

Use a Kill A Watt monitor to get your daily usage
https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor

What @wiseacre said, measure it and then you'll know. Also see the other recent thread here: https://diysolarforum.com/threads/needing-a-small-all-in-one-for-freezer-only.83051/

 

[Mwashere]

Is this your freezer?
View attachment 211992

Looking at comparable models at HomeDepot, I'd guestimate your unit might consume between 1.6 and 1.8kWh of power per day. But, as E.Cho mentions, the best option is using the killawatt to actually determine your real-world consumption. But, we can start with the 1.8kWh value and work with that till you have better real-world numbers.

Let's assume you have to run this unit on standard 120V 60Hz AC. The inverter just being on, whether or not the freezer is actually running, will also consume power. That varies from inverter to inverter, but let's say it's 1000Wh per day. So, to keep the freezer on 24/7 you need 1.8kWh + 1.0kWh = 2.8kWh of power. Let's round that to 3.0.

1000W at startup is a bit large for a 1000W inverter, so you want to look at one that can handle 2000W. You really never want to run your equipment at the ragged upper edge of their specifications.

You're in Texas, so you're in a solar-rich area. Let's assume you get about 6 sunhours (sh) per day in June and 3 sh in December. Go with the lowest number, never the highest. Assuming you need 3000Wh of power each and every day, and you get 3 sunhours of solar in December, you need 3000Wh/3 sh =1000W of panels. At 12V, that would be a substantial number of amps, so you are better off with a 24V system, that is a 24V battery bank, powering a 24V inverter.

Assuming at startup you are consuming 1000W, from a 24V battery bank that would be ~ 42Amps. Look at getting 400Ah lead-acid batteries, or maybe 200Ah of Li batteries to support that level of battery drain.

Keep in mind that these are numbers that I came up with, not YOUR numbers. I suspect that this is a commercial-grade unit that consumes more than a domestic HomeDepot model, so plan on these numbers as the bare minimum of what will be needed.

So, minimally, you'll need....
1000W of panels, say four 250W residential panels
40+amp charge controller
2000W 24V sine-wave inverter
200-400Ah batteries

Ideally how much would all this cost? Ballpark figure…

How much would it cost to run a 5 ton AC unit for 3 days?

 

[Mwashere]

Is this your freezer?
View attachment 211992

Looking at comparable models at HomeDepot, I'd guestimate your unit might consume between 1.6 and 1.8kWh of power per day. But, as E.Cho mentions, the best option is using the killawatt to actually determine your real-world consumption. But, we can start with the 1.8kWh value and work with that till you have better real-world numbers.

Let's assume you have to run this unit on standard 120V 60Hz AC. The inverter just being on, whether or not the freezer is actually running, will also consume power. That varies from inverter to inverter, but let's say it's 1000Wh per day. So, to keep the freezer on 24/7 you need 1.8kWh + 1.0kWh = 2.8kWh of power. Let's round that to 3.0.

1000W at startup is a bit large for a 1000W inverter, so you want to look at one that can handle 2000W. You really never want to run your equipment at the ragged upper edge of their specifications.

You're in Texas, so you're in a solar-rich area. Let's assume you get about 6 sunhours (sh) per day in June and 3 sh in December. Go with the lowest number, never the highest. Assuming you need 3000Wh of power each and every day, and you get 3 sunhours of solar in December, you need 3000Wh/3 sh =1000W of panels. At 12V, that would be a substantial number of amps, so you are better off with a 24V system, that is a 24V battery bank, powering a 24V inverter.

Assuming at startup you are consuming 1000W, from a 24V battery bank that would be ~ 42Amps. Look at getting 400Ah lead-acid batteries, or maybe 200Ah of Li batteries to support that level of battery drain.

Keep in mind that these are numbers that I came up with, not YOUR numbers. I suspect that this is a commercial-grade unit that consumes more than a domestic HomeDepot model, so plan on these numbers as the bare minimum of what will be needed.

So, minimally, you'll need....
1000W of panels, say four 250W residential panels
40+amp charge controller
2000W 24V sine-wave inverter
200-400Ah

Is this your freezer?
View attachment 211992

Looking at comparable models at HomeDepot, I'd guestimate your unit might consume between 1.6 and 1.8kWh of power per day. But, as E.Cho mentions, the best option is using the killawatt to actually determine your real-world consumption. But, we can start with the 1.8kWh value and work with that till you have better real-world numbers.

Let's assume you have to run this unit on standard 120V 60Hz AC. The inverter just being on, whether or not the freezer is actually running, will also consume power. That varies from inverter to inverter, but let's say it's 1000Wh per day. So, to keep the freezer on 24/7 you need 1.8kWh + 1.0kWh = 2.8kWh of power. Let's round that to 3.0.

1000W at startup is a bit large for a 1000W inverter, so you want to look at one that can handle 2000W. You really never want to run your equipment at the ragged upper edge of their specifications.

You're in Texas, so you're in a solar-rich area. Let's assume you get about 6 sunhours (sh) per day in June and 3 sh in December. Go with the lowest number, never the highest. Assuming you need 3000Wh of power each and every day, and you get 3 sunhours of solar in December, you need 3000Wh/3 sh =1000W of panels. At 12V, that would be a substantial number of amps, so you are better off with a 24V system, that is a 24V battery bank, powering a 24V inverter.

Assuming at startup you are consuming 1000W, from a 24V battery bank that would be ~ 42Amps. Look at getting 400Ah lead-acid batteries, or maybe 200Ah of Li batteries to support that level of battery drain.

Keep in mind that these are numbers that I came up with, not YOUR numbers. I suspect that this is a commercial-grade unit that consumes more than a domestic HomeDepot model, so plan on these numbers as the bare minimum of what will be needed.

So, minimally, you'll need....
1000W of panels, say four 250W residential panels
40+amp charge controller
2000W 24V sine-wave inverter
200-400Ah batteries

ideally how many would I need to run for 24hrs? Please

 

[wpns]

How long is a piece of string? Fermi calculation: 5KW isn’t unreasonable so 360 KWHR if it’s running 24x7. If there’s no solar for those 3 days, EG4 PowerPro batteries will cost you $95K plus another $5K for the inverter.

Now, none of the above is any more than a SWAG, so take the measurements and report back. You need to answer some of the basic questions instead of posting new unrelated ones.

 

[OffGridForGood]

To start the freezer, you need 8.6 amps at 115v, or roughly 1kw. You will need an inverter capable of 1kw, panels to charge a battery, and enough battery to run it as long as you want.

I disagree - the FLA (full load amps) may be considerably less than the in-rush to start up the freezer.
Typical motors can be x3 or more the FLA rating for in-rush upon start up.
I have a Kil-o-Watt and an In-Rush meter, my own freezers draw close to 20A to start, then drop down running. My three freezers consume about 1.2 kWh per 24 hours, but they are all located in a cool basement room, not exposed to excessive room temps ever.

Playing around with my mobile AIO - the MPP 2724 which has plugs built right into the side of the inverter, this small unit can start and run one freezer with a 100Ah LFP battery. This AIO is only $285 (plus shipping) and just needs PV and a battery since the 120v-outlets are built right into the side of the inverter. NOTE: this unit can not be expanded (parallel) and is limited to 800W of solar PV - although you can overpanel it.

 

[hidiyguy]

I disagree - the FLA (full load amps) may be considerably less than the in-rush to start up the freezer.
Typical motors can be x3 or more the FLA rating for in-rush upon start up.
I have a Kil-o-Watt and an In-Rush meter, my own freezers draw close to 20A to start, then drop down running. My three freezers consume about 1.2 kWh per 24 hours, but they are all located in a cool basement room, not exposed to excessive room temps ever.

Playing around with my mobile AIO - the MPP 2724 which has plugs built right into the side of the inverter, this small unit can start and run one freezer with a 100Ah LFP battery. This AIO is only $285 (plus shipping) and just needs PV and a battery since the 120v-outlets are built right into the side of the inverter. NOTE: this unit can not be expanded (parallel) and is limited to 800W of solar PV - although you can overpanel it.

Where are you seeing it for $285? I see ebay at a little over $400 and watts 247 is $642.

Edit: just found maximum solar in Taiwan for that price, but shipping to US adds $106.
Have you purchased from them and are they legit?

 

[PotusGobbleBottom]

Thank you so much, so I figured this freezer doesn’t all the time run 8.6A, I assume hits that 8.6 when the motor kicks in. Roughly how many batteries and panels would I need if I wanted to run all day?

My freezer 17.2 CUbic feet 1 year old, only takes 600 watts / day right now.

 

[OffGridForGood]

Where are you seeing it for $285? I see ebay at a little over $400 and watts 247 is $642.

Edit: just found maximum solar in Taiwan for that price, but shipping to US adds $106.
Have you purchased from them and are they legit?

"This AIO is only 285 (plus shipping)"

Correct - I bought all five of my MPP's from Maximum solar. Legit.

 

[efficientPV]

I took a totally different approach as I consider a freezer a battery. I have MSW inverter, an old car battery for starting surge only and run almost exclusively from panel power. Battery will only supply 5 minutes of runtime if sun goes away. Fridge only starts when battery is past float and will shut down at 12.6V. It just free runs when sun power is available and thermostat is set much colder than usual.

 

[Doggydogworld]

I took a totally different approach as I consider a freezer a battery. I have MSW inverter, an old car battery for starting surge only and run almost exclusively from panel power. Battery will only supply 5 minutes of runtime if sun goes away. Fridge only starts when battery is past float and will shut down at 12.6V. It just free runs when sun power is available and thermostat is set much colder than usual.

Clever. What if it's cloudy several days in a row?
Those purple Arctic Ice Tundra Series packs can hold the freezer at 5 deg F when the sun isn't shining.
Is your freezer frost-free with automatic defrost cycle?
How do you keep the freezer from running when battery is below float?

 

[efficientPV]

It is microprocessor controlled that looks at battery voltage constantly with preventions from hot starts. Should it run too long it automatically shuts down and resets after a period. This prevents inverter faults from shutting down system. Freezers typically have short run times and the cold motor actually functions as a heat sink. In the morning this prevents long runs with a hot motor which is inefficient. It is amazing how little you can get away with if an engineering approach is taken. No defrost.