Utilizing Solar with FHU

[TomG2]

I most often park with Full Hookups. I am trying to figure out how to use solar energy to reduce my electric bill and of course be available when I do occasionally park off the grid. I enjoy my air conditioner, microwave, etc. so I do not want to simply pull the plug while parked and plugged into shore power. I am thinking of a very modest system as I cannot see investing several thousand dollars for something that might only save me ten.

[Almot]

TomG2 wrote:
I wondered if I could get any benefit from solar while in my RV park. The investment will be made for dry camping, but I hate to think that it would not give me a few dollars in return for just sitting there ready to go. If it is simple as turning off the converter, I will give it a try. If I have to plug/unplug every few hours, then it is not worth the experiment.

Scenario is still not clear.

If there is a shore power - you don't need a solar. Compared to shore power cost, with fulltime living it may take 10-20 years to return the investment, depending on your camp electricity rates and whether you can install solar yourself or have to pay a thousand or two for labor.

With fulltime boondocking it will take much shorter time because your only other choice would be burning a generator fuel, this costs a bit, not to mention generator maintenance (and purchase if you haven't got one yet).

Yes, using solar can be as simple as "turning off the converter". You will need a transfer switch to turn the shore power on when you need to use air conditioner, everything else can be taken care of with solar. In terms of parts cost, for things like microwave and other 120V devices that draw over 600W power (but less than roof A/C), you will need solar at least 600W, 700-900W is better, plus 2000-3000W PSW inverter, and battery bank at least 400 AH. Roughly $1400-1800 not counting batteries (and labor, if any).

[TomG2]

I knew the economics of solar were not that great when full hookups are available. I wondered if I could get any benefit from solar while in my RV park. The investment will be made for dry camping, but I hate to think that it would not give me a few dollars in return for just sitting there ready to go. If it is simple as turning off the converter, I will give it a try. If I have to plug/unplug every few hours, then it is not worth the experiment.

[MrWizard]

Forget about it ...
You will save next to nothing on the electric bill
Your only real savings, would be the extension of dry camping time
A/C MW heat use large amounts of power, to realize any electric bill savings your system would have to be large enough to power those items from a large inverter, being powered by the large solar array
On shore power once batteries are fully charged, then charging becomes a mute point, as parasitic drains and maintenance require very little power, the power for lights and maybe the TV could be off set by solar, but the MW and a/c , electric heat etc.. Would still be on the meter, Not inverter powered by solar, unless you get a full-time off grid system, a modest system is not going to power the MW or a/c, and even if you bought a large 3000w inverter, you would need a large battery bank

So yes you can get some minor reduction in the electric bill, by using solar charging the batteries and using an inverter for low power items
But the couple of dollars a month might not justify the expense of the install
Solar on an RV, in a FHU campground, is not grid tie feedback
Supply power to grid during the daytime peak and then use power st night at the lower rate, you can't do that in a campground, it's not like a house
Unless you set it up that way on your own property

We have solar, we full time, mostly off grid
And we use the generator almost everyday, MW a/c , are on the generator , solar battery power handles the fridge tv pc lights etc..
Big power items are almost exclusively generator
I can run the coffee maker or the MW or the vacuum from the inverter, but I pay for it with extra generator powered recharge time into our bank of (8) batteries
We mainly have the solar and the batteries, because we have a residential fridge and I am a power hog using the pc many hours a day

The best way to save on the electric bill, is too run everything you can in the TV from propane, fridge, water heater, heat using outro propane

[time2roll]

Just don't plug in unless you need the air conditioner. Run the rest from your battery and inverter.

[scrubjaysnest]

TomG2 wrote:
Thanks to all for their suggestions. I pay $0.15/kwh or about $90.00/month. I am thinking that I might use 200 watts of solar per hour for 10 hours a day equaling 2 kwh/day. This might be a fun and educational day to save ten dollars a month?

This isn't very practical. You will save more just changing out the 12 volt bulbs to LED. Might want to review this link:20 Golden Rules of Solar.
Your biggest electrical user is the A/C and refrig. Put the frig on gas to save a little more.

[TomG2]

Thanks to all for their suggestions. I pay $0.15/kwh or about $90.00/month. I am thinking that I might use 200 watts of solar per hour for 10 hours a day equaling 2 kwh/day. This might be a fun and educational day to save ten dollars a month?

[Golden_HVAC]

As stated above, shutting off the circuit breaker to your battery charger / converter will stop it from consuming 120 volt power to keep the battery full overnight. However that same circuit breaker might be supplying all the 120 volt circuits for say the bathroom, basement storage compartments, and such.

You could unplug the converter/charger. If it is easy to get to, this might work out well. On my RV, I have a 400 watt solar system and my converter/charger is actually a inverter/charger and it is easy to shut it off when not needed - most of the year.

What about the solar system? A pair of 140 watt solar panels will supply your 'normal' needs. You can buy those here for about $229 each. SunElec.com

As for mounts, buy a few feet of 2" angle aluminum (Home Depot) and cut to 6" long. Drill three holes 3/16" for #10 screws into the roof, and 5/16" for the bolt into the solar panel frame.

Wire: #10 romex from Home Depot, grey water resistant UV resistant and direct burial type. Run the wire down the back of the refrigerator vent to the basement, to the batteries.

Controller: Get a PWM 20 amp controller they are cheap now, about $20. It will turn on the solar when the battery is low, and shut it off around 14.0 volts.

Wiring is pretty simple. Just keep the ground wires to one side and +12 on another.

Good luck,

Fred.

[red31]

unplug/unbreaker the converter/charger.
add solar to supply 12v loads and charge battery.

[brulaz]

Your full hookups meter your electrical usage?
Have never been at a campground like that, but guess it must be a seasonal site.

Like others said, seamlessly merging a solar/battery/inverter system with shore power would be expensive.

So I would just manually switch from one to the other system as needed. Use shore power only when you need the extra capacity: A/C and so on, or when your batteries need charging and solar isn't doing it.

[RoyB]

Nothing else needed - Just use the circuit breaker on the Power Distribution Panels to control the converter/charger unit. The shore power will run all the things connected to the 120VAC side the solar panels will keep the battery bank topped off to run everything on the 12VDC side.

If you have a low wattage Power Inverter setup for HDTV and a few other low wattage 120VAc items then the Solar Panels will be used for that as well by keeping your battery bank topped off.

Just think of the solar panels as a battery charger...

Roy Ken

[gbopp]

How about hooking up a On/Off switch inside the RV? Then you could turn the shore power on and off as you need it without going outside.
That would be relatively inexpensive.

[harold1946]

In moat cases when hooked to shore power, the system is in bypass and no power is being supplied by the batteries. The batteries are being maintained by the converter and solar would supplement only.

[Shadow_Catcher]

I am sure it can be done but you are looking at two different systems, a grid tie inverter supplying power to offset shore power, and you will also need a solar controller to supply power to your batteries. And never the twain shall meet. They must be kept separate electrically, but with switching/relays it can be done
Check out the forum and see what they suggest, and yes it will likely get expensive.

Northern Arizona Wind & Sun