Inverter or not.

[NM_Shooter]

I am really struggling with this decision.  I can't decide if I want my lights to run directly from 12V, or if I am going to use an inverter.

I'm now leaning toward direct 12V.  (Again.   Before I was leaning away from it.  I could be a congressman with this sort of 'splaining)

My cabin is small enough that electrical losses will be minimal if I use 12V.  I've been researching inverters, and most of them have a standby power consumption of 1 Amp.  That's 12W just sitting around idling. 

I could rig up a switch to control a power relay to the inverter, and just power it when needed, but I'm thinking it is not worth the effort.  I'll just put in 12V florescent fixtures and be done with it I guess.  Although I do prefer incandescent bulb color, but I'll have to compromise on something!

I'll probably have a 12V outlet on the wall near the "kitchen" area, and get a small portable inverter for things that might need AC. 

I think I will still run some 120VAC wiring in case I change my mind later, and want to use a generator or something.

But for the next 15 minutes, that is how my mind is made up!

Comments?

[MountainDon]

If you are only powering lighting and there is no microwave, blender or TV/DVD in the foreseeable future I would go 12 or 24 VDC, but wire up for future AC as a precaution.

Solarseller.com has great prices on Thinlite FL fixtures, 12 VDC or 24 VDC.

As for whether or not to use an inverter with a remote switch to power on and off, it works, but can be a bother. Ask the missus. One of the reasons I eventually moved away from a split DC/AC system was I did not want to write an instruction manual for daily operation or maintenance.

I have a Cobra 1575 mod square wave inverter I will sell. It has the ability to be switched on-off remotely, but I don;t have the cord. Plugs into an RJ-something jack

[MountainDon]

Also, if you are wiring up and want to install a breaker panel, buy a Square D, series QO. The QO breakers are rated for DC service as well as AC, even though the ones in the store won't have the DC label. Good to 48 volts, but due to NEC regs should only be used to a maximum 24 VDC system.

[muldoon]

I think the flexibility of having an inverter when you occasionally need it is worth getting one.  However, having it running and inline drawing phantom watts is undesirable. 

If you want the colored bulbs, have you considered the 12volt LED style bulbs for MR16 (track lighting)?   They draw almost nothing in power 2-5 watts each, draw pure 12volts and come in warm white light if desired. 

http://www.theledlight.com/12volt-led-bulb.html
http://www.ledwholesalers.com/store/index.php?act=viewProd&productId=309

etc.

Yes I know they are some-what pricey at $20 a bulb, but keep in mind the 75,000 - 100,000 hour life.  And the very low power usage earns points as well for an offgrid setup.  The more you conserve in usage requirements, the less panel and battery you need.  You might save more than you think. 

I just built a light fixture with 3 2 watt luxeon bulbs and it illuminates a swath for 60 yards at night.  If you have those 3 on a track fixture it would light up a room just fine as well.  (I'm no expert but what I found was that you'll likely need more than one as they are a bit spotlight focused instead of lighting up a large radius in one). 

[tc-vt]

Here's a page that has information on different bulb types including their efficiencies.
http://www.megavolt.co.il/Tips_and_info/bulbs_at_glance.html

Some thoughts to consider (if you haven't already):

You will need a charger for your batteries for any charging you might do with a generator.  Good inverters have a built in three-stage charger with equalization.  The good inverters will have a search mode which will reduce the standby power usage when there are no loads on. 

An inexpensive way to get a pure sine wave inverter is to find a used UPS uninterruptible power supply for computers.

Many of the compact fluorescent DC bulbs are US made!  So are the fixtures.  The regular Edison screw in light bulb base on the compacts allows you to use regular fixtures - cheaper and wider selection of Chinese home depot stuff - instead of limiting yourself to the selection of DC fixtures with built-in ballasts.  You can also more easily convert to AC lighting later.

I'm wired for AC and am also running DC ceiling fixtures throughout, so that I will not be without light if the inverter ever becomes toast.  I'm also putting in a few DC receptacle outlets.

Tom

[NM_Shooter]

Yeah, well, it took me all of 46 minutes to rethink and now I'm back on the fence.  Thanks to Don for selling me a Cobra inverter for cheap. 

I think I am going to wire for both.  Figure it out on the fly.

Sigh.  Being a EE, you would think this would be the easiest part for me.

-f-

[glenn kangiser]

Your system is smaller than ours, but I just keep increasing ours as we want then figure if we ever get in a tight, we can start to conserve more then .

We still want more now and I just want everything to be like a normal house - no 12 or 24 volt.

I don't run the load search feature on the inverters to save watts as some things won't kick it on and I don't want to fool with it.  Yup... I'm lazy.