Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-01-2019, 14:18   #1
cruiser

Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,304
Cool idea: fridge powered entirely by solar panels, no battery use

https://joeyh.name/blog/entry/fridge_0.1/
https://joeyh.name/blog/entry/fridge_0.2/
https://fridge0.branchable.com

Similar idea, but separate https://www.ice-energy.com
__________________

john61ct is offline   Reply With Quote
Old 08-01-2019, 15:14   #2
Senior Cruiser
 
newhaul's Avatar

Cruisers Forum Supporter

Join Date: Sep 2014
Location: puget sound washington
Boat: 1968 Islander bahama 24 hull 182, 1963 columbia 29 defender. hull # 60
Posts: 8,444
Re: Cool idea: fridge powered entirely by solar panels, no battery use

Rich builds systems just like this for remote off grid situations . Not just for boats.
CoolBlue Overview
__________________

__________________
Non illigitamus carborundum
newhaul is offline   Reply With Quote
Old 10-01-2019, 19:46   #3
cruiser

Join Date: Dec 2006
Posts: 405
Re: Cool idea: fridge powered entirely by solar panels, no battery use

Ozefridge manufacture real hold-over systems with 'Sure-thaw' control that require as little as one run cycle per 24 hours. The built-in ECO2 power management causes this daily run cycle to occur once the voltage reaches 13.5VDC and therefore abundant (otherwise wasted) power is used... NO battery drain!

Click on data to enlarge...

Click image for larger version

Name:	Estimate Sample 100Lt 30C ambient Caninet 2C to 4C.png
Views:	82
Size:	273.3 KB
ID:	183626
The above chart is of a typical 100 litre (4+ CF) top opening fridge with 75mm of urethane insulation, maintaining a cabinet temperature of 2 to 4C in a 30C environment. Note the bottom window indicates sufficient daily (24hr) refrigeration is provided by one 3.25 hour run cycle, programmed to run when power is abundant like once the solar or whatever is no longer needed to recharge the batteries and such abundant power would otherwise be wasted.
A correctly sized system can be engineered to operate most properly insulated cabinets similarly to the one above, thus requiring virtually no battery consumption.

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems
OzePete is offline   Reply With Quote
Old 10-01-2019, 23:43   #4
cruiser

Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,304
Re: Cool idea: fridge powered entirely by solar panels, no battery use

Thanks Pete. Can that setpoint be tweaked by the user?

Or startup triggered by a switch or external relay, e.g BMV-712 based off SoC?

Adapted to freezer usage by stacking multiple units + thicker insulation?

Used for 24V or 48V circuits?
john61ct is offline   Reply With Quote
Old 10-01-2019, 23:45   #5
cruiser

Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,304
Re: Cool idea: fridge powered entirely by solar panels, no battery use

Same Qs for Rich of course

@SV THIRD DAY
john61ct is offline   Reply With Quote
Old 11-01-2019, 01:00   #6
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Boat: Bestevaer.
Posts: 11,927
Re: Cool idea: fridge powered entirely by solar panels, no battery use

This is certainly possible, but you end up wasting a lot of solar power.

The solar panel size needs to be larger, as there is no battery system to help average the times of good and bad solar output. So if you want consistent temperatures, it is easy to cope with the short night time period, but cold storage is limited so the solar output has to large enough to supply enough power for the lower solar output days or even weeks.

Solar is cheap so if you have the room to fit a larger solar array, such as on a roof, and dispense with the complication of a battery system it has appeal, but I don’t think it has any application on a yacht where the room for solar is limited and a battery system is already fitted.
noelex 77 is online now   Reply With Quote
Old 11-01-2019, 01:54   #7
Registered User

Join Date: May 2010
Location: Sydney Australia
Boat: Fisher pilothouse sloop 32'
Posts: 1,677
Re: Cool idea: fridge powered entirely by solar panels, no battery use

Quote:
Originally Posted by noelex 77 View Post
This is certainly possible, but you end up wasting a lot of solar power.

The solar panel size needs to be larger, as there is no battery system to help average the times of good and bad solar output. So if you want consistent temperatures, it is easy to cope with the short night time period, but cold storage is limited so the solar output has to large enough to supply enough power for the lower solar output days or even weeks.

Solar is cheap so if you have the room to fit a larger solar array, such as on a roof, and dispense with the complication of a battery system it has appeal, but I don’t think it has any application on a yacht where the room for solar is limited and a battery system is already fitted.
Ah, I read the post as no battery use, not no battery system. As I read it the suggestion is to use excess solar when it is readily available, as in would go to waste, to recharge the fridge with a system similar to that suggested by pete.
But I could be wrong, it has been known to happen.
__________________
Rob aka Uncle Bob Sydney Australia.

Life is 10% the cards you are dealt, 90% how you play em
Uncle Bob is offline   Reply With Quote
Old 11-01-2019, 09:11   #8
cruiser

Join Date: Dec 2006
Posts: 405
Re: Cool idea: fridge powered entirely by solar panels, no battery use

Quote:
Originally Posted by john61ct View Post
Thanks Pete. Can that setpoint be tweaked by the user?

Or startup triggered by a switch or external relay, e.g BMV-712 based off SoC?

Adapted to freezer usage by stacking multiple units + thicker insulation?

Used for 24V or 48V circuits?
Hi John, the Ozefridge's ECO2 set point value (trip voltage that forces the refrigeration cycle to run), is user adjustable although we set it at about 13.5 VDC which suits most situations. Also the controller panel has a switch where ECO2 (the 'start and run when abundant power is available), can be switched off.

Not sure what 'BMV-712 is but the ECO2 power management system is automatic and now standard on all of our hold-over eutectic systems.

The same feature applies to freezer applications.

Cheers, OzePete
OzePete is offline   Reply With Quote
Old 11-01-2019, 11:10   #9
cruiser

Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,304
Re: Cool idea: fridge powered entirely by solar panels, no battery use

Sorry, Victron's bank monitor, has a programmable relay,

so able to turn a load dump ON

based on its AH counter reaching say 90% SoC, rather than just using voltage.

Or an IGN switch if I want the freezer running as soon as my high-output alternator kicks in. . .
__________________

john61ct is offline   Reply With Quote
Reply

Tags
battery, panels, solar, solar panels

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Is it a bad idea to be ENTIRELY dependant on renewable energy on my 45' trimaran? FloatingDutchMn Engines and Propulsion Systems 87 22-12-2019 20:22
Do you cool your solar panels to get more power? BambooSailor Electrical: Batteries, Generators & Solar 30 20-06-2015 05:46
Crew Available: Novice, but Location and Schedule Are Entirely Open Monkeypunch Crew Archives 0 12-04-2010 10:56
Powered USB Hub vs Powered USB Cables Bryan Kemler Monohull Sailboats 2 20-01-2010 16:24

Advertise Here


All times are GMT -7. The time now is 02:41.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.