Solar power

[Cam85]

Hi everybody I haven't been on here for a while.
I'm wondering if there are ant tech heads on here that have had a bit to do with solar power systems I could use some healp figuring it all out.

Here is the scenario I want to run 2 engel friges 50litres each and 3 light bars 12volt all at about 3 meters long each I also want to include a 12volt water pump and then there's also an electrician fence the 12 volt tape kind just to keep a couple of horses in.

The ideal is to run the whole show of a couple car of car batteries deep cycle or outherwise.
The question is how much panel do I need and how to manage the system.

There is one out her variable that is how to rig up some kind or climate control system I'm thinking a reverse cycle split system inverter and a small silent petrol generator.

Oh I nearly forgot this is all to go in a 3 horse angel float.

If I'm gunna have a generator can I use the generator to top up the batteries 4 the 12 volt system.
I really scratching my head about this one and could use some pointers

 

[Delmer]

Hey Cam, haven't heard from you in a bit. You're always up to something. I'll take a swing at it, it won't be until morning, that's a lot of googleing for me.

The prices on those Engel fridges is shocking to me as a cheap American, don't you have Haier upright fridges (10 cubic feet) that use 100 watts running? Same with the split system air conditioning, do you have window air conditioners, or roof top RV units? I can't see how a split system is worth the hassle for a horse trailer? Am I understanding right, or missing something?

 

[Queenslander]

Cam,
Iam just in the process of doing the same thing, in my case, a gooseneck trailer for three blokes to camp out while doing roadworks.
Iam running 110 litre and 50 litre fridges, a pump for showers, a swag of tiny LEDs and a tv for a couple of hours a night.
I've got two 250 watt panels and two 120 ah deep cycle batteries.
While it's worked alright so far, it looks like I've got plenty of panel power but could be a little marginal on battery storage, which is easily fixed.
Also have one of these 25 amp chargers hard wired in the system, so if you start the genny to run the ac it will top up the batteries at the same time.
http://www.projecta.com.au/Products/BatteryChargers/Intelli-Charge.aspx
They can be left continuously connected and used as a 12v power supply if required.
I took a ''suck it and see " aproach, as you can ask a dozen people and get the same number of varying answers.
Cheers, Greg

 

[Plebeian]

There are quite a few ways of setting up what you have suggested.
I would keep the electric fence solar system separate from the water pump and fridge system. Electric fence can get hit by lightning etc. If the area is not large; a small electric fence unit with a built in solar panel might be enough if there are permanent fences with an inner ring wire.. Use a horse wire e.g https://am.gallagher.com/nz/product...ncing/permanent-fencing/wire-and-cable/G91200
rather than the tape, maybe.
There are a few online calculators to determine solar calculations, optimum panel angels etc.
Are you planning to use some kind of pressure control on the water pump?
Maybe have an auto start or manual over ride system to charge the batteries with the generator.

 

[Delmer]

Silly me, the thing you want for the cheapest (least watts use, and initial cost) is a small 5-7 cubic foot chest freezer, with you own improvised thermostat. Much better than an upright fridge if you can stand the inconvenience. I know a DC fridge seems attractive, but the inverters are so good and so cheap that AC is what everybody uses around here.

 

[Queenslander]

That's a pretty cool (pun intended) idea Delmer.
I've never heard of it before, but after some googling, it is actually very simple.
Thanks for the tip.

 

[Scrub Puller]

Yair . . .

a gooseneck trailer for three blokes to camp out while doing roadworks.

Bloody good one Queenslander I thought that approach had been abandoned!

We always supplied caravans of course ( one was a three axle Carapark custom built for Carter Brothers)

Young bloke stickraking out the back here is living at the motel in town and drives fifteen kays to have lunch at the servo . . . I guess indirectly the customer will pay. (shakes head)

Cheers.

 

[check]

Another option is a propane fridge. Mine is about 8 cu.ft. Dometic 2 door with freezer above, had it 8 years. Uses about a 1/4 gallon of propane a day. It does add a little heat to the kitchen, though.
Remember that whatever you do, fridges need to be very level to work.

On electric ones, I have a Sundanzer chest freezer (12VDC or 24VDC) and really love it, had it 6 years. They use very little power. You can get them with a fridge thermostat and use them as such.

 

[Queenslander]

Bit of a sore point for me at the moment Scrub,
As you know, councils here are constantly saying they just don't have enough money to spend on roads.
As a business, we are offering road maintenance services to these councils at the best possible price and camping on the job is part of this.
We get a lot of work from one shire who appreciate the cost savings, but another persists in using their own workforce regardless of cost.
They are about to start a resheeting project 80 miles from town and the whole crew of about six will be commuting that distance to and from the job.... so about 4 hours a day wasted.
Iam disappointed that we have missed out on a job that Iam certain that we could do for almost half the price but Iam furious that they are wasting my rate dollars like this.
I'll have to go and have a good lie down now before I blow a valve.

 

[Cam85]

Take it easy Queenslander we can't have have ur blood pressure rising.
Tank you all for ur input the electric fence is only a small job and won't get much use what's the difference between dc and ac power.

Also I'm all ears when it comes to climate control remember we get extreme weather here and this float won't have any insulation.

There is a lot more to this than I first thought .

 

[Cam85]

Hey Delmar sorry mate I've got no idea on watts or anything was thinking engel fridge due to space restrictions and easy to pick up and put in back of ute and so on trying to increas versatility the ideas with the reverse cycle split system inverter was to try and combine low power usage and have kick ass cooling and heating durability is a concern also.

The water pump would b pressure controlled gas cooking and hot water solves that one did a bit of googling and holy hell different panels management systems this is a real minefield.

I feel like a bit of a goose as I don't even know how to calculate Ohms law a !!!

 

[Queenslander]

I know where you're coming from Cam, but you really can't stuff anything up....the worst that can happen is a flat battery.
For what your suggesting, I would start with one large panel (230-250w), a solar controller... get at least 30amp so you can add another panel later if required,and maybe two 120ah deep cycle batteries.
Like I said, suck it and see, then add additional panel or batteries if needed.
The controller should have a volt metre so you can see how your batteries are going.
I reckon a charger is essential so you can top up your batteries with a generator if you do get into trouble.
The little Flojet style pumps are the best way to go for water supply.
Run the electric fence, as Plebeian suggested, as a stand alone unit.
There are plenty of 240v caravan style a/c units on the market, or maybe a truck sleeper cab cooler like an Icepack but I think running a climate control system on battery power would be (almost) out of the question.
Just my thoughts, but Iam certainly no expert.
Cheers, Greg

 

[Willie B]

If it's in the budget consider a controller from Outback Power systems. I'll presume you won't always be parked out in full sun. A small inverter generator, I've got my eye on a Honda, will serve to recharge when sun isn't available. Go with LED lighting, propane refrigerators, and the AC is a big draw for solar in the size you are talking. Check out what works among the off grid world. Be very careful of RV venders. Having looked around, I believe most of that clutter is designed to separate you from your money, then is non functional.

 

[Delmer]

I know where you're coming from Cam, but you really can't stuff anything up....the worst that can happen is a flat battery.
For what your suggesting, I would start with one large panel (230-250w), a solar controller... get at least 30amp so you can add another panel later if required,and maybe two 120ah deep cycle batteries.
Like I said, suck it and see, then add additional panel or batteries if needed.
The controller should have a volt metre so you can see how your batteries are going.
I reckon a charger is essential so you can top up your batteries with a generator if you do get into trouble.
The little Flojet style pumps are the best way to go for water supply.
Run the electric fence, as Plebeian suggested, as a stand alone unit.
There are plenty of 240v caravan style a/c units on the market, or maybe a truck sleeper cab cooler like an Icepack but I think running a climate control system on battery power would be (almost) out of the question.
Just my thoughts, but Iam certainly no expert.
Cheers, Greg

Well, after an afternoon of fun and excitement (chickens, motorcycles, cops, beer and chasing in no particular order), what comes to mind but Cam's solar! I did some searching and calculating, and I come up real close to Queenslander. I will quibble with the economics though. Here, the panels will cost $1/watt which will make the panel more expensive than the batteries up front, but the batteries will last 10 years with PERFECT care, in your setup I'd guess more like 2-5, that will make the batteries much more expensive per year than the panels which should last 20-50 years. For that reason, I'd go with more panels per battery. Ideally the batteries will discharge 40%, if they go flat very often at all they'll die much sooner. That's deep cycle, automotive just aren't worth the effort, unless you have a steady supply of free used ones to use, even then it's a lot of messing around to keep up with them.

Those engel fridges seem not especially efficient, at least compared to the chest freezer fridge conversion, which is a fair comparison to a chest cooler IMHO. Two small coolers will use roughly the same as one MUCH larger chest freezer. Of course you can't move a full one around easily so there is that. Whatever you get, make sure there's no amp draw when it's not running, especially an AC load will keep your inverter running and drain the batteries in no time. The inverter needs to be able to shut off when there's no load and turn back on when it senses the load. LED lights will run DC so they won't matter. A DC fencer will be designed to run on a battery so will hook up just fine, you DON'T want an AC fencer, the inverter will use more power staying on than the fencer will use.

All of this is ignoring your climate control. If it was me, I'd run that on a small diesel, I've seen two cylinder Yanmar reefer units that would do the trick, or rig it up with a smaller diesel and a belt drive compressor.

 

[lantraxco]

If you have the coin:

http://www.cstk.com/fleet-solutions/aftermarket-heat-ac-systems/arctic-breeze#

http://www.rdac.com/resources/blog/better-no-idle-ac-system

 

[Delmer]

Well that's not that bad, 55 amps for 6,000 btu puts it in the same league as a better used window AC unit, nothing notable efficiency wise, unless you're comparing it to running a big diesel to run the cab AC... That's roughly half the efficiency of the best central AC units. So you add three more big panels and you'll have AC with the sun shining, whether an expensive truck system, or a cheap window AC with an expensive inverter.

 

[Queenslander]

Well, after an afternoon of fun and excitement (chickens, motorcycles, cops, beer and chasing in no particular order)
.

This has the potential to be much more interesting than solar panels and the like.opcorn

 

[mitch504]

Going back to Delmer's off-hand suggestion for climate control, around here you can pick up a used reefer unit from a truck or trailer for next to nothing. Nobody in their right mind would depend on one to protect a $45,000 load of seafood, so they are nearly free, but most have thermostats that can be set from deep-freeze to heating. They run on little diesel engines, and shut off and start automatically.

 

[lantraxco]

Well that's not that bad, 55 amps for 6,000 btu puts it in the same league as a better used window AC unit, nothing notable efficiency wise, unless you're comparing it to running a big diesel to run the cab AC... That's roughly half the efficiency of the best central AC units. So you add three more big panels and you'll have AC with the sun shining, whether an expensive truck system, or a cheap window AC with an expensive inverter.

Correct. To be fair these units are designed for over the road rigs so the design parameters are a bit different.

 

[Cam85]

All good points am thinking a float is not the best way to go am rethinking the matter and am leaning towards a small truck with a crate plenty of room easier to mount solar panels on and weight is no longer an issue.


If nothing else we have established one thing the fence is better off as a stand alone unit