RV solar Utility Co payback?

[Dav L]

Hi, skimmed the first four pages of Going Green posts and didn't find it...

Love the idea of solar. But hardly have used the RV. So, what if the solar panels on the RV fed the S&B which could feed the utility company for excess power reimbursement?

Detroit Edison is very solar friendly (1/3 of power is now solar / wind). I assume my small system would be a "category 1" installation for parallel revenue sharing small systems. DTE has published inverters and relays that they have approved for connection to the utility power system.

So, what would be the hook up?

Solar panels, charge controller, inverter, monitoring on RV as usual so the solar could aid in boondocking for when the RV is in mobile use.

You drive home...you "plug in the RV to the house". Today that means a 50A connection to my barn / shop's utility panel (this is on a second commercial rate utility power meter).

What would I be connecting to share the RV solar to the house?

What equipment would be mounted in the house to transfer the juice from RV to house electricity?

And, just to be thorough, assume the RV solar had more capacity than house draw and the excess could be sold back to the utility company (Retail $ - transfer cost). For my needs, this would be unlikely that solar is more than my demand.

Certainly I could have two systems, one on the RV (which will hardly get used) and one on the barn (all of which would be used). But what fun would that be?

Thoughts?

[okcnewbie]

Originally Posted by Dav L

Hi, skimmed the first four pages of Going Green posts and didn't find it...

Love the idea of solar. But hardly have used the RV. So, what if the solar panels on the RV fed the S&B which could feed the utility company for excess power reimbursement? Thoughts?

I loved having solar on our Rv.
It never did pay for itself. Very quiet though.

[NewBlackDak]

RV solar is setup for off grid use, and to generate DC power. To sell electricity you need a grid-tie system that makes AC power. Grid tie requires the grid to be up in order to provide a baseline sine wave for AC generation. A grid tie system on your RV will make it useless for unplugging.

I’m not saying it’s impossible, but it will add a level of complexity and cost that will probably never pay back.

[Smitty77]

Suppose the best way to approach this research, is to go talk with the Cities planning department, as well as the utility itself.

If neither has any problems with the idea, and of course you follow the codes. Then the logistics become how close can you get the RV to the place it would be cord connected house power. Doubt they'll want to see or approve a cord laying on the ground. And then the devils of the details on how to send the power from your controller to the house. Bypassing the feed to your batteries. A fat cord if it's much of any length. And, the longer, the more the drop...

With the price of solar panels dropping, might just look for some good deals and set up a system for the Stick & Bricks...?

But I know that I don't know enough to share anymore then those thoughts. And I salute the creativeness of double duty usage of your RV's solar system!!!

Will follow the thread to see what shakes out...
Best to you,
Smitty

[astrocamper]

I have 1405 watts of solar on my trailer roof. I installed a manual 30 amp 10 circuit transfer switch system at my house circuit breaker panel. I can hook up my pair of Honda 2200 generators and power critical systems in my house during a power outage. This keep my fridges, furnace, lighting and computer related stuff going during outages. I can cycle through my circuits to keep the load below my maximum generator output. For example I can run a fridge for an hour and then switch it off and run another fridge for an hour.

During the warmer months when my panels are not snow covered I connect my trailers 2200 watt pure sine wave inverter to my home transfer switch. I shift several of my UPS protected computer related circuits to my trailer during daylight hours. I switch back over night so I don't deep cycle my trailers batteries after sundown.

This is the type of transfer switch I installed:

https://www.homedepot.com/p/Reliance...0CRK/205793178

[Smitty77]

Originally Posted by astrocamper

I have 1405 watts of solar on my trailer roof. I installed a manual 30 amp 10 circuit transfer switch system at my house circuit breaker panel. I can hook up my pair of Honda 2200 generators and power critical systems in my house during a power outage. This keep my fridges, furnace, lighting and computer related stuff going during outages. I can cycle through my circuits to keep the load below my maximum generator output. For example I can run a fridge for an hour and then switch it off and run another fridge for an hour.

During the warmer months when my panels are not snow covered I connect my trailers 2200 watt pure sine wave inverter to my home transfer switch. I shift several of my UPS protected computer related circuits to my trailer during daylight hours. I switch back over night so I don't deep cycle my trailers batteries after sundown.

This is the type of transfer switch I installed:

https://www.homedepot.com/p/Reliance...0CRK/205793178

Cool beans!! I did not research our linked transfer switch. And hav no idea what the regulations are in your area. Or the OP's area too.

I do believe that most utilities, require a failsafe method from alternate power sources feeding your house hold panels, from back feeding the grid.

In the San Diego area, they do want power from Solar to help augment the overall 'grid'. But, they also want to have control over what can be fed back into the grid, and 'when' it can be fed. For example, say wind knocks down a power line, they do not want power coming 'back fed' fed into the lines - as it could hurt either a utility worker and or someone else just happening to be near that downed power line..

So working with the local officials and utilities is recommended. I know I don't know enough about this stuff to provide guidance on how to accomplish what the OP is trying to do... And of course many sources of power supplies, either gas/diesel/natural gas/battery pack/solar/wind - provide emergency power to 'on grid' homes across this country!

Best to all,
Smitty

[astrocamper]

The transfer switch is per edge circuit. The downstream edge circuit is either on power company mains bus bars or on generator position. There is no way for any power from generator to back feed to power company mains.

Each edge circuit has a 3 position toggle Main/Off/Generator

It is very simple and straight forward to wire. You can read the manual online.

[Dav L]

Originally Posted by astrocamper

This is the type of transfer switch I installed:

https://www.homedepot.com/p/Reliance...0CRK/205793178

Forgot to mention I also have a 15kv Generac propane backup generator and an automation transfer switch in the House. That will switch primary use circuits to run on generator automatically. I also have some manual breakers to back feed both the geothermal / water heater main panel (runs off a "cheap" utility power meter) and a second main panel that powers rest of house / boat house. So, more toys to play with in the design.

This is a little bit philosophical until I / we figure out a way....then I can decide what's practical and what's fun to wire.

[Ivylog]

My 900W of solar generates about 20 cents of power/day. Post #2 sums it up... never going to pay off the cost even with free labor.

[astrocamper]

I can shift about 4-5 kilowatt-hours per day or about $12 a month. I put in the transfer switch so I could run my critical stuff in my house off of my pair of Honda EU2200 generators. The power shifting is just because I can after installing the transfer switch.

Obviously my panels are worth a lot more to me when I am camping in my trailer off grid about 95% of the time.

[SteveJ.]

Originally Posted by Ivylog

My 900W of solar generates about 20 cents of power/day. Post #2 sums it up... never going to pay off the cost even with free labor.

Something doesn't seem right with that system and/or the math.

Data?

[Dav L]

Originally Posted by astrocamper

I can shift about 4-5 kilowatt-hours per day or about $12 a month. I put in the transfer switch so I could run my critical stuff in my house off of my pair of Honda EU2200 generators. The power shifting is just because I can after installing the transfer switch.

Obviously my panels are worth a lot more to me when I am camping in my trailer off grid about 95% of the time.

So, you have a few modes of operation:

House:
1) Running off utility company power
2) Running off Generator(s) (manual flip of transfer switch)
3) Running off RV solar panels (manual flip of transfer switch).

RV:
1) Running off house AC (typically utility company). Same as campground pedestal. 30 / 50 amp 110 line.
2) Running off Solar / Battery / Inverter
3) Running off mobile generator?

How are you connecting RV battery to House? RV battery to RV inverter to a 110 volt cable? Is this cable independent of the RV mode 1) 30/50 amp cable?

Is there a solar system in the house when RV is mobile? Are there battery / inverter in the house?

[astrocamper]

I don't usually have my trailer connected to my house power outlet. I have enough solar to keep the trailer going unless it is snowed over in the winter. In that situation I will plug in my trailer if I want to use anything in the trailer requiring power when I am getting no solar.

I have a 20 amp power cable from the 20 amp outlet on the side of my 2200 watt inverter going to an outlet on the outside wall of the trailer. The rest of the trailer is powered via the transfer switch in the inverter.

I run a 20 amp extension cord to a 20-amp to 30 amp adapter that connects to my outside generator input plug.

The inverter is always on in the trailer.

I flip one or more circuits on m manual transfer switch to the generator input plug which is connected to the trailer inverter. If it is a sunny day I will flip enough for 4-5 amps of 120 volt power when I leave for work at 7:30 am and flip it back to mains power when I get back home at about 5:30PM. The circuits I am flipping go to a UPS in that area so I don't have any computer, DVR or TV doing a restart from power disruption.

I typically shift my networking rack, my home office, my living room tv and DVR stuff to the trailer on a sunny day.

I look at my BMV-712 using bluetooth on my iPhone when I am in my house after I return home. If the batteries are close to 90% SOC I will do the same the next day. If they are discharged much more because of poor solar production I will not flip power over the next morning and let the batteries get a full 100% SOC.

If we experience a power outage. I will go on the NV Energy web site and look for the estimate of restoration of power. If it is less than an hour I will run computer stuff off my trailers batteries. If it looks like a long outage and/or I want to run more stuff in the house I will bring out my generators and hook them up to the transfer switch input plug.

I don't have any solar in the house.

I prefer to consider my solution power diversity/backup not payback.

I have used the transfer switch and generators for a 5 hour outage last summer on a hot Saturday. I ran my computers stuff, our home evaporative cooler and watched football all afternoon on generator power.

I have used the transfer switch and trailer power for 3 outages that lasted less than an hour each time. I kept all my computer/network stuff and Dish satellite and TV going off the solar/battery power during the shorter outages. I installed the transfer switch June 2019.

[Ivylog]

Originally Posted by SteveJ.

Something doesn't seem right with that system and/or the math. Data?

OK, that’s the average of the first summer with solar dry camping out West. Yes, with 7 panels tilted, a clear cool day, I got 5 KW or 75 cents... near perfect conditions. Many days the solar barely made enough power to run the residential refer, 1.2KW...15 cents.

The OP is in MI and I couldn’t find how much solar he has but doubt he will average 20 cents/day especially if he cannot tilt the panels living that far north.

The reality of solar on a RV it’s more feel good than economics. Yes, if you are FT, winter in a southern state (no AC needed), a large solar system can provide most of your power. Still probably a 10 year payback if you did it DIY and if you leave off the cost of batteries. Here is some info on my DIY: https://www.irv2.com/forums/f56/upda...ll-426063.html