Advice for a beginner!

[icarus]

Mike,

In my experience, the Morningstar has a idle draw of .055 amps,, .66 watts or ~ 16 watt hours/day.

Tony

(Source: Morningstar specs)

[thx1138]

..great feedback all.

I thin I am going to go with the SureSine..I don't need much power for initial lights and rather then running a 12v system I can use the wiring that exists and turn off the pump at the panel and use it when I turn on the generator.

I am going to order from ebay I think..shipping is a little high but what can you do.

Next challenge...30 cm of snow tonight...I wish I was in Arizona instead of Nova Scotia...more to come after the weekend.

[thx1138]

..snow..great fun.

Well I ordered the 200w SureSine as it will take care of all my basic needs to start off..in a year I will upgrade if I need to but I want to start small...so thanks for the advice.

Now, wiring. I have read the installation notes:

==================
Mechanical Specifications
Dimensions
213 x 152 x 105 mm ( 8.4 x 6.0 x 4.1 in)
Weight
4.5 Kg / 10.0 lbs
AC Terminals
Max. Wire Size 4 mm2 / 12 AWG
DC Terminals

Max. Wire Size 2.5 to 35 mm2
14 to 2 AWG
Remote On/Off Terminals
Max. Wire Size 0.25 to 1.0 mm2
24 to 16 AWG
Enclosure
IP20 Cast anodized aluminum

==============
I know the wiring is only going to be 5-6 feet from my batteries to the inverter an from the inverter to the panel..could I get recommendations about wire size..I have been attempting to talk to some local for wiring but they are not very knowledgable on 12v wiring..and do I need different types of wire to run from the inverter into the panel since it will be 120 at that point?

Also, in an earlier post someone posted about size of array vs battery bank size..is there a link that can better explain this?..I have never even thought about that but as suggested I could always take 2 batteries out of the array to compensate and use them elsewhere.

[Cariboocoot]

The simple answer to all wiring: always use the largest wire size you possibly can. This includes battery inter-connects.
Wire is wire: AC/DC doesn't make any difference in that respect.
The battery bank has to be large enough to supply your usage needs, and the PV array has to be able to replace that at a sufficient charging rate over the course of how much sunlight you get in a day. Since only experience can tell you that, start with estimates and be prepared to expand.

[icarus]

The suresine will produce 600 watts of surge at 120vac, or about 5 amps. It will draw, off the 12v battery better than 50 amps! Us a wire size calculator to figure out what is required for 50 amps. (#6 maybe??) I think I have wired mine with #6. At the very least fuse the wire at the battery for the smallest wire between the battery and the inverter. I think that morningstar spec calls for a 50 amp fuse. Fact of the matter you will only be drawing somewhat less than 25 amps for any duration.

As CC says, in any event use the biggest wire you can,, within reason. Line losses give you nothing,,except room heat you may not need or want. Keeping the inverter as close to the batteries as possible is a good idea, to reduce loss.

Remember, line loses are inversely proportional to the voltage. Higher voltage, lower loss, lower voltage, higher loss. The wire is rated in amps, regardless (in most cases) of the voltage.

Tony

PS Remember, snow is your friend,, it adds reflection on the panels, and in my case adds considerably to my net harvest. That assumes that it isn't snowing!
T

[niel]

thx,
use at least #6 for a voltage drop percentage on that section to be about 1.14%. remember that this gets added to other dc wired sections for the total dc voltage drop percentage that should be kept under 5% overall per nec, but the lower the % the better. if you can use #4 or better that would even be better for you, but may not be necessary. use #12 for the 120vac component from the inverter to the panel.

[thx1138]

thanks for the info!

Yes, snow is my friend in one way..for solar production..its NOT so good when I have an unfinished road and I have to park 1/2 km away...but trouncing around in knee deep snow has been great cardio!

Rain today through Sun..with +12 C expected so it should be gone soon.

[jacobs]

BTW propane refrigerators aren't very efficient and they burn a lot of propane. Getting rid of ours saved a lot on gas, and it doesn't take much electric to run our modern 16 cu.ft. 'frige: 240 watts running (cycles about 1/3 of the time) and a nasty 500 watts when it goes into defrost mode, but that doesn't last long either.

Propane refrigerators are typically very inefficient, however during the heating season, your refrigerator is helping to heat your home. Bottom line, free refrigeration during the winter if you heat your house with propane.

[icarus]

Propane refrigerators are typically very inefficient, however during the heating season, your refrigerator is helping to heat your home. Bottom line, free refrigeration during the winter if you heat your house with propane.

This idea is sort of right,,,,but there are practical limitations.

Any time you "do work" with electricity (or propane) you generate waste heat. If you use a Propane fridge, and have the flue properly vented outside, the net heat into the building is far less efficient than burning the same amount of fuel in an efficient furnace or space heater for example.

The same can be said of ovens and stoves. Cooking a roast in the oven contributes significantly to the heating load of the kitchen. Even using a compressor fridge generates "waste" heat 12 months a year,,, during the heating season, that heat is used to reduced the heating load in the house.

Light bulbs are another one. I had one guy suggest to me that using cfl's was stupid because the kwhs saved by the cfl bulbs had to be replaced from another source. Very true, but the reality is that there are way more efficient ways to heat your space than with light bulbs! (or fridges or water heaters or what have you)

The reality is to use all our energy as wisely as we can. Keeping heat in when we want it in, and getting it out when we want it out. For example, I have vent louvers behind my fridge with a t-stat controlled fan. In the summer time the fan vents the heat off the condenser out the building. In the winter, it vents the heat into the room. I try to capture as much of the heat from the flue in the winter by using a steel vent pipe and letting it radiate off before exiting the building. In the summer I insulate the flue.

As for the fundamental efficiency of propane fridges, I contend that if you insulate the cabinet, put a fan on the coils, and fill them properly, they can be pretty darn efficient. As I have said before, we use 1 gallon of propane per week +- for cooking, water heat and fridge. Having said that, if I had to do it over, I would consider a good conventional fridge to run off the solar and cut the need for propane by that much more.

Tony

PS. It would be an interesting test, (that I'm sure someone has done) to compare, on a cu.ft./cu.ft basis to compare the btu requirements of a good compressor fridge and a good propane fridge on a annual fuel efficiency basis. I know that my dometics use ~1500 btu/hour, but the duty cycle is under 50% in the summer, and way less in the winter.

[jacobs]

If you use a Propane fridge, and have the flue properly vented outside, the net heat into the building is far less efficient than burning the same amount of fuel in an efficient furnace or space heater for example.

Interesting....I've probably seen close to a hundred gas refrigerators of all makes and sizes, new and old, (including a huge 1957 double door Servel) installed and never seen any provisions for outside venting on any of them. Since they weren't vented outside that means 99%+ efficiency or like I said before "free refrigeration" in the winter.