Enough power?

[Alamak]

I have 6 400 watt panels. Two of the batteries pictured and 1 inverter pictured. Is this going to give me enough to go off grid for extended periods? Possibly a couple of weeks.

 

[fo4imtippin]

I have 6 400 watt panels. Two of the batteries pictured and 1 inverter pictured. Is this going to give me enough to go off grid for extended periods? Possibly a couple of weeks.

More than a lot of folks have, but way too many variables to tell from the info provided.


How big is the bus?
Is it insulated?
How many A/C's?
What is all being powered?
Do you need inverters or Air Conditioners on 24/7 or can you turn off when you leave the bus?
Where are you planning on staying? Northeast (not a ton of sun), Florida in the summer, need a lot of A/C.


Im looking at doing an EG4 8kw when it comes out (like the 6000XP) and one of their wall mount 14kwh batteries. I want to be able to run my loads 24/7, and im going to backfeed my house when it parked at home.

 

[Alamak]

45 foot coach. Not insulated yet. Still building. 1 rooftop ac with 2 possible. Washer dryer. Standard rv loads? Such as lights etc. Can turn acs off if absolutely necessary but would rather not as returning to bus would require longer ac use to cool everything down. We are chasing the sun but not planning of hot weather much. I plan on being tied in to the bus for charging as well as a generator. I figured I can add 4 more 400w panels and 6 if no choice.

 

[fo4imtippin]

45 foot coach. Not insulated yet. Still building. 1 rooftop ac with 2 possible. Washer dryer. Standard rv loads? Such as lights etc. Can turn acs off if absolutely necessary but would rather not as returning to bus would require longer ac use to cool everything down. We are chasing the sun but not planning of hot weather much. I plan on being tied in to the bus for charging as well as a generator. I figured I can add 4 more 400w panels and 6 if no choice.

I assume you are going to spray foam. My brother has a 40ft coach bus. Its well insulated and it takes 3 roof A/C's to keep it cool in Florida. It can run 2 A/Cs in cooler areas.


If you have the chance, i would recommend running a 2 head mini split and mounting the outdoor unit in the under storage bay.


Its hard to say if one 6000xp and 10kw of batteries will be enough. Normally, i would say that one 6000xp is enough for almost any skoolie conversion, but 2 roof AC's might put you at 3600 watts. Electric Water heat could eat up the rest and then you dont have enough to turn on washer or dryer. If you arent sure, start with one and leave enough room for 2. You can always add one and parallel them together. This would also give you redundancy over one large unit. Its also possible to wait for the 8kw or 10kw unit EG4 is releasing this year. They already have a 12kw unit (18kpv) that would work, but its 4 times the cost of the 6000xp and you dont need all those features for off grid only.


As far as batteries, the server rack batteries are solid, but you may consider their wall mount versions as they have built in heaters, as well as fire suppression pouches. Based on what im thinking, youll probably want more than 10kw anyway. The wall mount versions are 14kw and just a slightly lower cost per kw than their server rack batteries. This would be useful if you are mounting in your underbay storage which is where i would put it.

 

[Alamak]

Sadly I have already purchased the gear. I sent a request to a couple of solar providers. I told them what I would be powering and what my off grid intentions would be. This is what i was sold.
Im hung with it now. I will call the company that sold me this and explain to them again what our goals are. If I have to get more panels i have found a way to do so. I never understood how 6 400w panels would be enough to begin with. I truly appreciate the knowledge. I am a retire electrical contractor but never worked with dc current and never claimed I could without some help. D.C. is a totally different world for sure.

 

[fo4imtippin]

Sadly I have already purchased the gear. I sent a request to a couple of solar providers. I told them what I would be powering and what my off grid intentions would be. This is what i was sold.
Im hung with it now. I will call the company that sold me this and explain to them again what our goals are. If I have to get more panels i have found a way to do so. I never understood how 6 400w panels would be enough to begin with. I truly appreciate the knowledge. I am a retire electrical contractor but never worked with dc current and never claimed I could without some help. D.C. is a totally different world for sure.

No worries. I would run two 6000xp for redundancy anyway. They parallel nicely. You have very usable parts. Not sure if you are getting a markup on the equipment, but you can get them from signaturesolar.com at cost.

 

[More2See-SKO]

Watts generated, watts used and watts stored

I have 6 400 watt panels. Two of the batteries pictured and 1 inverter pictured. Is this going to give me enough to go off grid for extended periods? Possibly a couple of weeks.

This is a very loaded questions which needs to be broken down. First part is what can you solar array generate. At 25C and with the sun perpendicular to the panels you have the potential to generate 2400 watts. Flat panels always require cleaning as they collect a lot of dust. Dirty panels lose about 10% of the generation ability. Now heat, sun angle and day length come into play for power generation. For every 10 degrees the sun is from perpendicular you lose 3 to 4 percent of your array generation capability and every 1C above 25C you lose 0.5% of capability. Cooler temperatures below 25C actually improve power generation. The sun moves at about 15 degrees per hour so your latitude comes into play also. So a little math and you can figure out how much your array will generate for each hour of the day.

Now comes your hourly watt consumption needs during array generation hours. If your hourly day time watt consumption is going to eat up what the array is generating per hour and or more then there will not be extra to charge the batteries and or you are drawing the batteries down during the day which will leave nothing for night time hours.

I would suggest you do an energy audit of yourself for each hour and see what you are going to need, reduce or completely eliminate. Then you can see where you are at for the size of your array and storage requirements.

 

[Ariel19]

With 6 400-watt panels, 2 batteries, and 1 inverter, as shown in the picture, you can provide enough power to live off the grid for a short time. However, the ability to maintain this for a few weeks will depend on your daily electricity consumption and the weather.

 

[flattracker]

A suggestion - If you can install a second alternator on the bus engine, do so. When I converted the "old Crown" I relied on the starter batteries to run my inverter and almost ended up stranded with weak batteries. With a second alternator you can start the bus engine and bring the coach batteries up. If you install a generator, and an RV battery charger that can charge your coach batteries when it is running, or if connected to outside power. I configured my solar array with a second charge controller and a switch to connect one of my panel to it to charge the stater batteries. I am going into my third winter with this setup. So far the starter batteries are maintained at 13.8 volts from solar and the coach batteries are at 14.00 volts.
My RV charger is rated for 75 amps, and my solar arry is rated for 1 Kw.
I chose to wire my washer and dryer circuits to only work when running of outside or generator power. Generator is rated for 6.5 Kw. For now my heat is only propane.