Cabin Lighting

[nasty]

I want to get away from using our propane lights in our off grid cabin. What would be best 12v or 120v with inverter? Probably 3 fixtures in the kitchen and a few for living room and loft. Only going to be on for 4-6 hours a day in the spring/summer/fall. Then I mothball my solar for the winter because we are not there enough. I know it probably has to do with what type of light and all but I dont have any idea what I want to use yet. Just looking for suggestions on what people prefer to use CFL, LED....What type of fixture would work best? Does track lighting with a tranformer use more power?
400 watts of panels, 4-225AH batteries wired for 12v. 1000w pure sine wave inverter. Location is interior Alaska which gets a lot of sun in the summer months.
Any suggestions are greatly appreciated.

[maple flats]

As long as you can do without AC power you are far more efficient staying all DC. 12 volt is very easy to find, automotive bulbs in any fixture, or look at recreational vehicle lighting. When you go to an inverter for lighting you lose power just to convert the energy. If you do need some AC still keep lighting on DC for the efficiency.
To mothball your solar in winter presents some real issues. Batteries self discharge, a little each day. Batteries will freeze if not fully charged all of the time. For a battery to survive interior Alaska in the dead of winter will be next to impossible. I would suggest you take the batteries with you as you leave for winter, and then keep them on a trickle charger to maintain, or recharge them every week and do not let them freeze.
As far as transformers, they definately use more power, anytime you change electricity in voltage or form it is at an efficiency cost. Both inverters AND transformers generate heat while they perform their work. That heat is lost energy.
If you can stay at 12V DC you will be far ahead, even if you chose some DC appliances with their higher costs factored in, but if you really need AC you will need more panel wattage to perform the same tasks.
If you do decide to haul the batteries out you might consider using AGM batteries, for safety sake. Flooded Lead Acid must always be upright, AGM batteries can lay on their side if desired, but then there is a higher cost for AGM batteries to consider.
Decisions to make. Also, would a small inverter generator be a better choice for you? Place it in a sound barrier enclosure and you can have what you want. You could also charge 1 AGM battery to give you 12V lights when the genny was off.

[nasty]

Thanks for the reply. I take the batteries to main house in town and put on a trickle charger every winter. Thats a no brainer. I do have an inverter generator but I dont want to run it for lights just for power tools or extra power at night for some appliances. I have everything else worked out in the years of using solar just not the lights. Propane lights are nice and easy but are a waste when I have free power I could use. Almost free.

[Mike90250]

900Ah @ 12V is insane. You either have way too many batteries for a small load, or are trying to "get by" with cheap 12v inverter gear. that much battery in parallel, will eventually dissapoint.

A trickle charge for that battery would be about 10 amps, just to maintain its internal losses. If you have any sunlight in winter, I expect about 300W of panels would keep them charged up - If the controller can manage the cold. Charged batteries can handle pretty cold weather, but if they discharge, the water will freeze, and fracture the cells.

For 12V, distance becomes a major issue, 5' of wire is not bad, but more than 10' and your wire loss start to take a heavy toll, that's what lead to High Voltage grid systems, much less loss.

[dwightmilton]

What i did was had a florescent light and stick it under the overhead cabinets. To hide the light fixture I attached a strip of wood in front of it and it looks really good now. LED lights reduce power consumption.


Mod note
Links to advertising sites will not be tolerated.

[FloridaSun]

What i did was had a florescent light and stick it under the overhead cabinets. To hide the light fixture I attached a strip of wood in front of it and it looks really good now. LED lights reduce power consumption. Bathroom faucets

Strange place to advertise bathroom faucets

Mod note - good point Florida!

[Sunking]

Well you need to stop, get specific and rethink things through. It is doable, but you have some incorrect conceptions. As Mike indicated 4 batteries in parallel is really a bad idea. Assuming you use say CFL 13 watt bulbs on a 120 volt inverter we are looking at worse case 6 lights, using about 16 watts each, off the battery for 6 hours each day works out to about 600 watt hours per day. To give us some margin of error and wiggle room let's say 1 Kwh per day. Just based on 1 Kwh/day we can easily determine the appropriate battery size being:

12 volt @ 400 AH
24 volt @ 200 AH

Based on just that best arrangement is 24 volts using 4 Six Volt 200 AH batteries arranged in series.

Now the big question is solar panel wattage required. To do that we need to know the exact location where this will be, and what months it will be used. For example in Anchorage used from end of March to end of September your Sun Hours = 3 Sun Hours which is not real good because of September. If you were to use a MPPT Charge controller we are looking at a 500 watt panel system with a 20 amp charge controller operating at 24 volts. But keep in mind this is only an example based on a specific location and time of year. Move that same system to say Barrel AK for same time of year and the panel wattage requirement jumps up to 1000 watts. Location is everything.

[inetdog]

Hi, new here from Brisbane, Australia and I have just made a new home and want some fantastic lighting in it. First thing on which I am very confused is the colour of lights yellow or white? and then what you think about Fat Shack Vintage http://www.clicknbuyaustralia.com/br...shack-vintage/ is it a nice brand? My home is two bedrooms and not very big so I need lighting which make my home wide!

The color of sunlight is, more or less by definition, white. Which means basically that a standard white surface, which sends back light equally strongly at all visible light frequencies, will look subjectively white.
The color of "normal" incandescent lights is much more yellow. As you dim the incandescent lights the light will get even more reddish.

We are used to seeing the yellower light from candles, fires, and incandescent lights indoors at night, so many people seem to prefer that.
There is also strong evidence that excessively white/blue lighting at night can make it difficult to get to sleep normally.

The vintage style bulbs I have seen are all on the yellow/red side, and are not going to be good for daytime indoor work or for seeing what color clothing, makeup, paint, etc. will look like when you go outside during the day.

[BrandeX]

Hi, Thanks for your prompt response and help. I totally agree with your comments and advice.

[PNjunction]

Nasty - AC led's for me.

These are a grocery-store item now. I run the GE led's with standard screw in bases from a few different cheap msw inverters with no problem. They've come a long way in the last few years. They are much more efficient than cfl's too. Color temp has improved beyond the blue or intense white camping lights.

Yes, for a purist, a pure-dc solution is the most efficient, BUT for your application the inverter / ac led lighting would be just fine.

I ditched the CFL's not only for the increased efficiency of the led, but also for safety reasons here in earthquake country. Knock an led over and you have a dull thud. Knock a cfl, and you have broken glass and minute amounts of mercury. No need to deal with that.

For instance, the GE led's I run from the grocery store come in either soft-white, or daylight color temps. Efficiency of the latest are about this:

40w equiv: 6w real, or about 600ma when drawn from the inverter and measured at the battery terminals
75w equiv: 12w, or about 1.2A dc/inverter
100w equiv: 15w, or about 1.5A dc

The cool thing is that you don't have to hunt or buy them from specialty shops. Just bring one home, use regular ac to power it, and judge for yourself what the brightness and color temp looks like to you when you eventually power with an inverter in the cabin. Soft white, daylight, various shapes if you need decorative types etc. This provides a much more normal atmosphere than running the usual dc camping led's.

Also consider your daily cycle to consume about 10% of your battery capacity, or you'll be hurting them with shallow cycling. Ie, your bank is probably too big for just led lighting for 6 hours a day. (if that is your only load).

Hint: Find the watthour-rating of your battery, and divide by 2 for worst case (50% DOD). We can find the 10% point too with nothing but watts of the led lights.

Battery: lets say you are just going to use ONE of them:

12v * 225ah = 2700 watthours. BUT only half of that worst case is actually usable: you have 1350 watthours to play with daily for a 50% DOD - provided you can actually recharge to a significant amount from your array - see below.

OR, if you want to know the *minimum* you should be drawing of about 10% DOD, that means you should be pulling 270 watthours at least daily to avoid shallow-cycling. (uneven lead-sulfate during discharge, hot spots etc)

Add up all the wattage of the led's you plan to use, and for how many hours.

The BIG problem is your solar array and battery bank is mismatched. Rare, but it is actually too large! You either will never get them charged properly from your 400w array with deep discharge, OR you will be shallow-cycling them if you are very frugal. (not to mention additional problems of balance etc, but we won't go there).

Quite frankly, I'd advise trying to run the numbers to see if you can only run with just one, or at the very most two batteries. With your panel array, I'd shoot for just one battery. It will actually be healthier in the long run, especially if you can aim for low DOD's (perhaps 25% at most) with the led's.