Solar AND shore power at the same time.

[gruzzy47]

I'm thinking about adding some solar panels...

Obviously they're useful when not plugged in to shore power, but how does solar power interact with shore power?

Ideally, what I'd like to do while at a campsite with shore power, is to have most items (TV, lights, Laptop, etc) running off solar power, and the things like AC and microwave running off of shore power since it would take a unreasonably large amount of solar power to run those.

My reasons for wanting this are:

1.  I like the idea of going green
2.  It will save me a LITTLE on my electric bill...I know it won't save a ton
3.  2 ACs running on 30 amp service doesn't leave a lot of power for other stuff, that's where the solar would come in

Can it be set up so that solar is the first method of powering things, and if more power is needed it will draw on shore power?  Or something of that nature?  Or would I have to isolate the the power hogs from the other electronic devices somehow?

Thanks!

 

[legrandnormand]

Using the shore line provides you 115VAC for everything in your RV, including the converter; the converter, converts the 115VAC to 12VDC and charges your house batteries; the 12 VDC coming from your batteries will give you 12 VOLTS to operate your inside lights, furnace, ho****er, water pump, ceiling fans and probably your fridge, if it is a 3 way fridge.
By adding solar panels, the connections will go through a control panel controling  the voltage from your panels going or not to your batteries; they will actually keep your batteries charged if not plugged to shore line; if you are plugged in to shore line, the panels won't have any effect on your batteries, the control panel will cut the voltage between the panels and your batteries, since the converter will charge them.
 

 

[John From Detroit]

One of the lovely things about 12 volt side of life is it is DC.

This means you can parallel Solar, Battery, Shore power, ALternator and other sources and they all work together provided they are properly regulated

your converter (Shore power) is so regulated.. So is the alternator and that is of course what the solar charge controller does..

So.. Yes, will work, will work just fine. Should have not tribble at all.

 

[Ned]

If your solar power will supply enough to run all your 12VDC devices, then just turn off the converter/charger when on shore power.  If the solar can't keep up with the load and the batteries discharge, just turn the converter/charger on until the batteries are charged up.

 

[halfwright]

From:

http://www.rvmobilesolar.com/shore-power-and-solar-panels/

Yes, shore power and solar panels can be used at the same time. Both are systems used to charge the batteries and are designed to be compatible with each other, so there is no need to turn off the solar when shore power is plugged in. Both systems monitor the battery bank?s ?State of Charge? and supply power to the batteries as needed. When the battery bank is charged, both systems independently sense this and react accordingly.

Interesting note: Many RVs have inverters, which take battery power and ?invert? it into 110 Volt power (wall socket power) for use in the RV when the generator is not running and shore power is not connected. These two systems are also compatible and work together seamlessly.  If external power is supplied, the inverter senses this and stops using battery power and instead allows the incoming AC (110 volt) power to flow through to the loads in the rig.  If the external power source is disconnected, the inverter senses this  and immediately begins inverting power from the batteries to meet any loads in the rig. This happens so quickly (about 16 milliseconds), you don?t even notice.

 

[Gizmo]

if you are plugged in to shore line, the panels won't have any effect on your batteries, the control panel will cut the voltage between the panels and your batteries, since the converter will charge them.

Not completely true, it depends on how much solar power you have and how the charge controller is programmed.  The converter in most rigs is typically programmed to put out somewhere between 13.5 and 13.8 Volts.  Batteries should be charged at somewhere between 14.5 & 14.8 volts, ins some cases a tad higher.  If one programs their charge controller at the higher voltage setting, the solar system will win and take over where the rigs converter left off.  As an example the converter in our TT puts out 13.7 volts and our charge controller is set to put out 14.8 volts.  When we are hooked up to city electric our battery monitor will indicate 13.7 v at night and early morning before the solar powers up.  When the sun comes up and starts to become effective for my system, the voltage starts rising and if in optimal conditions or close to it, I'll see 14.8 volts.

 

[gruzzy47]

I know that they are compatible and can work together no problem, but that's not the issue.

I want the solar power to take precedence over the shore power....shore power is only used when solar isn't enough.  Rather than shore power running everything and the solar is just keeping the batteries topped off (or doing nothing).

Ned's solution is a good one.  Maybe simple is better in this case?  If everything works the way Gizmo has laid it out, maybe I wouldn't even need to turn the converter off...

 

[legrandnormand]

I know that they are compatible and can work together no problem, but that's not the issue.

I want the solar power to take precedence over the shore power....shore power is only used when solar isn't enough.  Rather than shore power running everything and the solar is just keeping the batteries topped off (or doing nothing).

Ned's solution is a good one.  Maybe simple is better in this case?  If everything works the way Gizmo has laid it out, maybe I wouldn't even need to turn the converter off...

Just do some home work and calculate the cost of being full time connected to shore power versus spending a few hundreds or ? one thousand $ to go solar !
How many years will your solar installation and batteries get paid back by your savings on shore power costs ? :-[

 

[gruzzy47]

Just do some home work and calculate the cost of being full time connected to shore power versus spending a few hundreds or ? one thousand $ to go solar !
How many years will your solar installation and batteries get paid back by your savings on shore power costs ? :-[

I'm aware of this...

The real cost savings would come from being able to spend a couple months of the year NOT at an RV site.  Just having the freedom to be able to do this...there's value in that as well.  Perhaps that's where MOST of the value is.  Extra savings while plugged in to shore power is just an added bonus, and a way to get a little more use out of the solar panels. 

 

[legrandnormand]

I for one often stop at Wall Mart or any other large parking lot that accepts overnite stays; my second choice is the Flying J's truck stops; I've also slept in certain patrolled rest areas.
Few years back, I boondocked for a few nitghts in the BLM just by the I-8 in AZ and CA and it was quite an experience.
BTW, I only have 2 house batteries, no solar panels but a good and quiet ONAN GEN. that runs ? 2 hours/day.
For longer periods, from a 3 day to a 6 month stay, I always get full hookups just to be the most confortable in my mh.