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+---- Thread: Question re Solar power (/showthread.php?tid=5965)
Question re Solar power - MaryN - 12 September 2013
I have a question. Does anyone know if there is a solar system that will generate enough power to run a fridge freezer, and is anyone doing just that?
RE: Question re Solar power - Highlander - 12 September 2013
We were talking about this only this afternoon.
We were talking about the possibility of going completely off grid once our wind turbine is working, what with that and the solar it started us thinking
You clearly know that the freezers will need a lot of power generated, and in our case the wind wouldn't do it [ with everything else],. and the solar wouldnt on dull days
So your best option is to buy a solar panel just for that freezer,... I think it is SD who is thinking of, or has done it,... who wanted a stand alone solar panel for each appliance
You would just have to get the right size panel
RE: Question re Solar power - Waylander - 12 September 2013
With a fridge or a freezer, you will have to allow for, something that is called 'cap start'.
A fridge may only require 500 watts to run it, but may require 1000w to start it running. This is because the motor has a capacitor attached which draws a higher load to start it.
Fridges stop and start quite frequently, as they switch off, to save power when the required temperature is reached, and start frequently to maintain that temperature.
You may be better using you solar panel to charge a bank of batteries then running from that.
Many motors have a 'cap start'.
Waylander
RE: Question re Solar power - Scythe13 - 12 September 2013
I'd look into the super insulated 12V freezers that eco homes have. They are SUPER efficient...and UBER insulated.
RE: Question re Solar power - Highlander - 12 September 2013
I have been thinking about those 12v freezers as well
RE: Question re Solar power - Nix - 12 September 2013
(12 September 2013, 21:36)Waylander Wrote: With a fridge or a freezer, you will have to allow for, something that is called 'cap start'.
A fridge may only require 500 watts to run it, but may require 1000w to start it running. This is because the motor has a capacitor attached which draws a higher load to start it.
Fridges stop and start quite frequently, as they switch off, to save power when the required temperature is reached, and start frequently to maintain that temperature.
You may be better using you solar panel to charge a bank of batteries then running from that.
Many motors have a 'cap start'.
Waylander
Absolutely right.
![[Image: thumbsup.gif]](http://www.nix.talktalk.net/thumbsup.gif)
The capacitor start is to give the electric motor more torque on start up. In reality, if you have a decent battery bank supplying a big enough inverter, you should be ok as most inverters can take a temporary peak load. When I tried to run my fridge and freezer on a 1kW inverter it was too much for it so it cut out. When using my 2kW inverter, no probs. The initial surge was almost exactly 1kW from each appliance so if both fridge and freezer happened to start together I suspect that the 2kW would also have been near it's limit.
After start up, with the motor running, each appliance used about 100 - 150W so easy peasy.
It can be done but only with the correct power inverter.
RE: Question re Solar power - Skvez - 13 September 2013
You will want a solar panel, battery bank and an inverter.
You need the batteries so that the fridge freezer can run at night if it needs to maintain the temperature.
First find the kW rating of your fridge freezer.
From this you can work out the maximum power the inverter needs to be and probably at least double it for starting surge
Then find the kWh/year rating of your fridge freezer
From this you can work out the average kW which can be used to calculate the size of panel you need (and also the minimum size of battery you need to carry you between daylight).
During the winter your solar panels produce very little compared to the peak sunlight hours of summer.
It's definitely worth looking at a super-high efficiency fridge rather than getting a much bigger solar system for a less-efficient fridge.
RE: Question re Solar power - uks - 13 September 2013
Defrost all frozen items in your fridge it keeps the fridge cooler requiring less power to run. There are 12 volt fridges and freezers available not just caravan types as you guessed it from the states.
http://sundanzer.com/
Some good in fro on this site in the product guides