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bobt
Newbie

Joined: 26/12/2009
Location: Australia
Posts: 17

Posted: 11:50am 26 Dec 2009

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hello solar mates,
im just about to buy a 80watt solar panel with regulator onback of panels from ebay and a 380watts pure sinewave inverter from jaycar,

I have a few questions if anyone can help as iv not been able to find on other
forums.

1)will the 80watt solar panel be enough to run the following via inverter;

A) 50 watt floor fan.
B) 32 inch lcd tv (mostly in the evenings for a couple hours)
C) dvd player
D) A laptop
E) A barfridge
F) A modem wireless
G) A desktop computer running at 450watts
H) A 22" lcd Computer Monitor

note not all at once either, but mostly the fridge, fan.

2)Will just one 80amp deep cycle battery be enough to run everything or would
A second battery be required?

thanks for any advice for my solar stuff

cheers
bob

p.s im just getting into solar and have a buget of $1,000

Tim_the_bloke

Senior Member

Joined: 15/11/2009
Location: Australia
Posts: 105

Posted: 02:24am 27 Dec 2009

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Fridges can be problematic. Fridges cut in and out with their thermostat and each cut in means restarting the compressor. Many 240V fridges will not run from an inverter as they have a surge cut in load. I have a 2000W inverter which runs power tools happily but will not start the 240V fridge. I have a couple of old 12V fridges which happly run directly from the batteries.
If you already have the inverter, test if it can run all these appliances using a car as the power source.
Running many appliances will flatten a battery quickly.
Edited by Tim_the_bloke 2009-12-28

KarlJ

Guru

Joined: 19/05/2008
Location: Australia
Posts: 1178

Posted: 04:16am 27 Dec 2009

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what state are you in, the daily output will vary according to the latitude, at best you might get on average ~400W of available power per day.

The smallest fridge I have aver seen, the hotel variety uses a couple of hundred a day. Most fridges use on average 600KW/hr/year or 1.6KW/hr/day thus you will need 4x as much grunt than you have there to run one of those.

Your desktop will also, kill it dead in less than an hour at 450W (but I doubt its actually drinking that much)

Sounds to me like you need a much larger array, connection to the grid or a wind turbine and some much bigger batteries say 600AH over the 80 you have.

another alternative could be some kind of solar tracker which will increase output by 40% and most importantly cut the drain to 1/4 of what it is now for starters.

Forget the PC use the laptop only and forget the wireless router, plug it in with CAT5 instead.

Luck favours the well prepared

Tinker

Guru

Joined: 07/11/2007
Location: Australia
Posts: 1904

Posted: 02:14pm 29 Dec 2009

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Bob, I do run a solar powered fridge but it requires heaps more $ than your budget allows.
It has the works of a very old domestic fridge rehoused in a home made 75mm thick insulated chest fridge cabinet. This fridge is now very efficient, bar fridges are notoriously not so - only 2 star rating on some.

This fridge is powered by a 1200W low frequency sine wave inverter which reliably starts the fridge. I doubt your inverter would start any 240V fridge. You have to consider that fridge compressors start up under full pressure and require a power 'kick' rated at many times its running watts on the label.

On the shed roof I have 420W of solar panels on a tracker. A MPPT charge controller and a 200Ah battery bank (24V) handles & stores all this solar power.
This bank also powers my house lights (CFL's) via the same inverter.
There is an excess of solar power available at this time of the year so an extra 100Ah of battery bank is on the shopping list.

You may seriously have to consider downsizing your list of solar powered devices or fork out heaps more money.
Start by including a total available power consumption figure of no more than 25% of your battery's full Ah capacity. This is the only way to get a reasonably long live out of your expensive battery.

Unfortunately, a stand alone solar powered system is not cheap - I will never get my investment back in my life time - but it gives me a warm fuzzy feeling writing this under solar powered lights with a solar cooled drink at hand

Klaus

KarlJ

Guru

Joined: 19/05/2008
Location: Australia
Posts: 1178

Posted: 10:22pm 29 Dec 2009

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Klaus, I'm darn sure it will pay back in your lifetime

What you did was paid your power bill up front for a few years.

200Ah and 24V -seems small cant imagine this cost you more than $1000, inverter likewise $1000 and panels with tracker $5K.

Trust me 7K on the power bill these days is not a long time

Luck favours the well prepared

Barry T Coles

Senior Member

Joined: 30/07/2009
Location: Australia
Posts: 109

Posted: 12:41am 30 Dec 2009

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Hi Bob
The max amps you will be able to pull from the 380 watt inverter is 1.58 amps before it shuts down.

Have a look for any compliance or manufacturers plate on the fridge to see if there is any rating, there should be something like: 230-240V AC 50~ and then the rated watts or amps, if its in watts you will know straight away where you are and as long as the rating is below 380 watt your laughing, if the rating is in amps this is easily converted by 240 volts X ? amp = Watt, IE 240 volt X 5 amp = 1200 watt.

Cheers
Barry

I need to learn from the mistakes of others.
I dont have the time to make them all myself.

bobt
Newbie

Joined: 26/12/2009
Location: Australia
Posts: 17

Posted: 12:49am 30 Dec 2009

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G'day everyone, thanks for your replies.

I will consider now spending an extra $200 saved up
for 160watt pannels,

As for the fridge situation, i will cross that off my
list for the time being, as i might save up for
one of those waco 12v/240 volts small portable fridges.

I will also cross off the desktop computer and just use
the laptop.

Im in eastern vic at the moment, suns usually up by 5.40am, the solar panels im getting are fold up case,

so i can move them to the side of my unit for early morning sun and move to the other side around 10:45am
for the rest of the day.

I have small 12v 6 amp/hour battery i brought from jaycar
its been running a 20globe LED lights off it at nighttime
for this past week , i bounce the light of the ceiling

I run this for about 3 hours each night, when i first
tried this the battery started at 12.7 volts after a week its down to 12.5 Volts.

Im hoping it will be ok for around 14 days and and the voltage will drop to around 12.0 Volts, then i can re-charge using my small 5 watt solar panel i have.

I will just put my 80amp hour battery away for the moment. i might even get another 80amp battery and couple
them together to have around 160amps,

that should be enough to run my fan through the day
and nighttime use,

although i did see on youtube an american bloke using a
108watt system and one 80 amp battery running, lights,
32 inch lcd telly, fan , cb radio and stereo system.

cheers
bob

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