Newbie. Input needed on a pole barn solar build.

[guito13]

Hi Everyone & Thank you in advance for any input. Please understand that I am a newbie and if I get terminology wrong I do apologize. Please be gentle!

I currently have a small setup that I have played around with for a year or so. I recently had a 60x40 pole barn built and I would like to at least have part of it (lighting / garage door opener / couple freezers or fridge and maybe a bit more) running on solar. I will probably eventually tie it to the grid to run some more energy hungry tools and such.

As far as supplies:

- I have a 60A solar charger which I think should suffice.
- I have 2x125w panels and i plan to get at least 2 maybe 4 more
- I currently have 1 LIPO4 100AH battery
- I have a 3000w / 6000w Peak inverter (PS1004-NP GoWise)

Right now I have 3 questions but would appreciate any additional thoughts as well:

1) I want to have a breaker box setup. I assume my current convert is not going to work for that application. Assuming I want to eventually be at a 50AMP system what Inverter would you recommend?
2) How many additional batteries would you go with?
3) I think I want to mount the panels on a post next to the barn. Reason is I am in MI and want to be able to easily get to them to wipe off snow during the winter.

I will update my main post here as recommendations come in.

Update 1: Assume goal is a 15KWH per day setup

Thank you in advance for your input!

 

[BentleyJ]

First step is to make a formal wish list of items that will be on system and include how many Watts each requires and how many hours per day they will operate so you can calculate kWh needs.

Then the system is sized based on the above.

 

[guito13]

First step is to make a formal wish list of items that will be on system and include how many Watts each requires and how many hours per day they will operate so you can calculate kWh needs.

Then the system is sized based on the above.

Thank you for the reply!

Based on my calculations (and adding some padding) lets say 15KWH / day

Just to run my small office ( I work from home ) which is basically a computer and montiors. Several interior / exterior LED lights as a backup to the main lighting. Smaller chest freezer in case of power outage. Then some misc. down the road items.

I am fine building up to that number with additional panels / batteries over time. I understand some equipment must be purchased up front to accommodate the end goal.

I really want to have it wired so i can utilize a breaker box.

 

[BentleyJ]

Based on my calculations (and adding some padding) lets say 15KWH / day

Some very "rough" numbers as an example. To produce a 15kWh/dy would require a 3kW solar array. Assuming they are oriented such that 5 solar hours could be captured. This is for full sun, clouds will reduce significantly.

Just to run my small office ( I work from home ) which is basically a computer and montiors. Several interior / exterior LED lights as a backup to the main lighting. Smaller chest freezer in case of power outage. Then some misc. down the road items.

An heating or cooling needs? Seems like the estimate of 15kWh/dy is on the high side for only the items listed above.

I am fine building up to that number with additional panels / batteries over time. I understand some equipment must be purchased up front to accommodate the end goal.

I really want to have it wired so i can utilize a breaker box.

While any inverter can be wired into a standard breaker panel the equipment you have now (12V to 120V inverter) is not compatible with your end goals of connecting to the grid eventually (240/120V split phase). In other words, the supplies listed above in the original post are not an expandable starter kit that can be added to. Its more of a small RV system.

Perhaps this is a stupid analogy but here it is. If you eventually want to do tournament bass fishing you can't start with a 10' aluminum dingy and keep adding 10hp motors and more fuel tanks until it becomes a Ranger.

 

[WindWizard]

I agree with @BentleyJ you have sort of painted yourself into a corner. It is better to start Solar with the end in mind and then purchase equipment accordingly. You can do it a bit of a time but probably the most important thing is to decide on what voltage you want your system to be. A 12 Volt system is limited to usually RV and typically does not apply well to a home application.

 

[guito13]

Some very "rough" numbers as an example. To produce a 15kWh/dy would require a 3kW solar array. Assuming they are oriented such that 5 solar hours could be captured. This is for full sun, clouds will reduce significantly.

An heating or cooling needs? Seems like the estimate of 15kWh/dy is on the high side for only the items listed above.

While any inverter can be wired into a standard breaker panel the equipment you have now (12V to 120V inverter) is not compatible with your end goals of connecting to the grid eventually (240/120V split phase). In other words, the supplies listed above in the original post are not an expandable starter kit that can be added to. Its more of a small RV system.

Perhaps this is a stupid analogy but here it is. If you eventually want to do tournament bass fishing you can't start with a 10' aluminum dingy and keep adding 10hp motors and more fuel tanks until it becomes a Ranger.

Hi,

I would like to work my way UP to 15kWh/dy. Was hoping for a setup I can add battery / panels over time. I understand other pieces need to be properly sized for the final goal at day one. No heating / cooling right now. Possibly smaller space heater to handle small office that will be framed in down the line.

To clarify, I have no desire to tie this system into the grid. I plan on having an off grid set of outlets and then an on grid set as well.

Was hoping to upgrade the inverter first to one that allows easy wiring into a panel then upgrade/add other parts (panels, batteries) over time. I was under the impression that my solar charger would be good to use since its rated at 60A.

Thank you again for your input.

 

[BentleyJ]

For off grid connecting to a breaker panel something like a EG4 6000xp would be a good, expandable starting point. Its a split phase inverter that can provide 240/120V and be connected directly to an off the shelf 100A breaker panel. This model can be stacked (paralleled to double, tripple etc output)
You could start with 1 x 100Ah battery (although that would limit the system to less than 5,000W) and add batteries along the way. There are several choices for rack mounted batteries where they just slide in. Depending on brand 5 or 6 100Ah modules per rack.

Other choices for value priced products would be MPP Solar, Growatt, Sungold, Deye. These are also known as All In One units since they have AC chargers & MPPT solar charge controllers built in.

For higher end products look into Sol-Ark, SMA, Outback, Schneider & Victron.

 

[guito13]

For off grid connecting to a breaker panel something like a EG4 6000xp would be a good, expandable starting point. Its a split phase inverter that can provide 240/120V and be connected directly to an off the shelf 100A breaker panel. This model can be stacked (paralleled to double, tripple etc output)
You could start with 1 x 100Ah battery (although that would limit the system to less than 5,000W) and add batteries along the way. There are several choices for rack mounted batteries where they just slide in. Depending on brand 5 or 6 100Ah modules per rack.

Other choices for value priced products would be MPP Solar, Growatt, Sungold, Deye. These are also known as All In One units since they have AC chargers & MPPT solar charge controllers built in.

For higher end products look into Sol-Ark, SMA, Outback, Schneider & Victron.

Thank you!

This is what I am looking for. It looks like the EG4 6000xp is an mppt AND an inverter in one, right? I'm such a novice that I did not know that they made such a thing.

If I started with one of these units, 2 more 125w panels and 1 more 100AH LIP04 Battery I think I could at least get the lights / Garage Door opener up and running.

Would you recommend wiring the batteries in series or parallel?

Thank you again!

 

[Mattb4]

Not all LiFePO4 batteries support series connection and generally you are better to buy ones that are built for the correct nominal voltage. Thus if you install a 48vDC AIO you will want to buy 48vDC batteries. You can connect more in parallel to gain more capacity.

Using an AIO you will not need to have off grid plugs and on grid plugs. Off grid AIO's have a ATS (automatic transfer switch) built in. The scheme is you bring in grid to the AIO's AC in side. The AIO's operates off either it or its inverter to supply AC out to your distribution panel in the pole barn.

 

[guito13]

Not all LiFePO4 batteries support series connection and generally you are better to buy ones that are built for the correct nominal voltage. Thus if you install a 48vDC AIO you will want to buy 48vDC batteries. You can connect more in parallel to gain more capacity.

Using an AIO you will not need to have off grid plugs and on grid plugs. Off grid AIO's have a ATS (automatic transfer switch) built in. The scheme is you bring in grid to the AIO's AC in side. The AIO's operates off either it or its inverter to supply AC out to your distribution panel in the pole barn.

Hi Matt,

Thank you for the reply! I think just running in parallel at 12v will suffice for my needs. I do not plan on running anything that is beyond the standard 110-120v range. Goal is to have a solar setup that can be wired to a breaker box then to outlets to power lights, small appliances (tv, chest freezer) and maybe a few other smaller items.

 

[BentleyJ]

If I started with one of these units, 2 more 125w panels and 1 more 100AH LIP04 Battery I think I could at least get the lights / Garage Door opener up and running.

As stated above, Its not recommended to pursue any reasonable sized home system with the items you currently have. Forget the 125W panels those are toys. There is a minimum startup voltage for the MPPT charge controller. Something 5 x 300W panels would appropriate. The PV string needs to operate at about 200V DC. The PV datasheet will have values for Vmpp. (Voltage at Maximum Power Point)

Would you recommend wiring the batteries in series or parallel?

Forget the 12V stuff. Get a 48V battery that matches the inverter. Multiple batteries connected in series will eventually get out of balance because the BMS does not have access to all 15 or 16 cells.

At this stage you should be reading the installation and operating manuals for the equipment of interest.

 

[Mattb4]

Hi Matt,

Thank you for the reply! I think just running in parallel at 12v will suffice for my needs. I do not plan on running anything that is beyond the standard 110-120v range. Goal is to have a solar setup that can be wired to a breaker box then to outlets to power lights, small appliances (tv, chest freezer) and maybe a few other smaller items.

I think you will find that sticking with 12vDC to be impractical for any standard 120vAC type loads. Remember that W=VA. Thus if you need to power a 120vAC item that draws 5 amps (600w) it would draw 50a at 12vDC.

My home system is 24vDC to 120vAC from 2- 3kw AIO's. I run 3.1kW worth of panels developing about the 15kWh per day. It is adequate for my purposes though I am contemplating going to a 48vDC system and a 240vAC split phase in the future. I mention this to explain that i have a bit of experience in small setups. When I first started down the solar path years ago I ran 12vDC LA batteries. I soon figured out it was marginal and more suited to RV's and boats (most of these folks have gone up in voltage theses days). If I was not dealing with so much legacy equipment and starting new i would be running 48vDc today.

 

[guito13]

Ok, I can sell my current items and start over. Any recommendations on budget friendly and user friendly components? I don't want cheap stuff that wont last but I also do not need high end items. If you had a clean slate knowing my desired outcome, what woudl you buy?

Again, scalable up to my number would be great so I can add as needed/budget applies.

Thank you again so much!

 

[Mattb4]

Sorry but I don't make recommendations on equipment brands. I suggest you take a look at reviews of particular ones that meet your needs. Many nice folks at the Forum here have made the effort to review models that they are trying. I have a couple made off the AIO's I am using. The owner of the Forum has many video reviews that he has done.

 

[BentleyJ]

Any recommendations on budget friendly and user friendly components?

I mentioned several Brands in post with timestamp 4:51am. Most of us are in agreement with @Mattb4, with regard to not making specific model # recommendations.

Look up the datasheets on a few different brands and then ask more questions.

 

[guito13]

Thank you again. I am speaking more about what specs I should be looking out for. How many panels and what watts/voltage? What AH/voltage batterie(s).

 

[Mattb4]

Thank you again. I am speaking more about what specs I should be looking out for. How many panels and what watts/voltage? What AH/voltage batterie(s).

First off, after you get a feel for your loads running current, starting current and what they add up to over a day, you need to have a good location for your panels. This usually means at minimum to be in full sunlight between 9am and 4pm. If you do not have such a location than numbers of what you need change drastically. Panels have ratings for wattage, voltage open cell designated Voc (this is the voltage where no loads are placed on them while they sit in full sunlight), Vmp which is panel voltage at maximum power point. Isc current short circuit and Imp current at max power point.

Locations will have an average sun insolation that you can find on the 'net based on Season and distance from the equator. Say for instance your location has a 5 hour average in May. This would mean that you could take the panels rated wattage and multiply it by 5 to get its potential production for a day in May. Understand this is not peak wattage that your panels can deliver (which is often about 75-80%) of rated but a days amount of watthours.

Thus to get a clue on the number of panels and what wattage you need to do some research into your area for what is possible.

Once you get a number for panel wattage you can than figure out types and numbers keeping in mind that your AIO with its SCC's (people often just call them MPPT) has specifications for max Voc and operating voltage plus current considerations. Some AIO's will have multiple SCC's on them.

Regarding batteries. They store power and are not a power supply. So if you discharge them you must recharge them to use again. Say you want to power your place for a day. You will need enough battery amp hours to carry the loads plus a bit more to cover loss. So going back to your load calculations you reached let's say 10kWh for the day. Likely to reach that from your batteries, if they are liFePO4, you will want 12kWh. 48vDC LiFePO4 batteries are nominal 51.2vDC. Thus 12,000wh/51.2vDC=234.3ah

One advantage to an Off grid AIO is the ability to use it as GAB (grid as backup). Doing this you can use less battery storage and simply have the AIO auto transfer to grid when the battery runs down to a selected voltage or SOC. This also covers you during bad weather periods. The AIO consists of ATS, SCC, Inverter/charger and a computer that controls functions for selection. If you size your AIO adequately you can grow your PV system over time by adding more panels and batteries.


Hope all this helps you get a start. As I mentioned the owner of the Forum here has many informative videos that can walk you through the process.