Off-Grid Solar Power System Cost Breakdown - How Much Did we Pay?
How much did it cost us to build our own 7200W 28kWH 5000W 120V Off Grid Solar + Lithium Battery power system? Less than you think.
Since re-locating to our off-grid desert homestead property a couple of years ago, we've been busy with all sorts of important infrastructure level projects.
This would house all our power and electrical gear for our solar power system, and double as an office and guest room.
As you can imagine, we got asked a lot how we put the system together and how much it cost.
The first question can be answered by this exhaustive installation and wiring guide article. And the second is right here!
Sizing our Off-Grid Solar Power System
Before we talk cost, let's talk sizing because as you know the amount of solar and battery storage you build will have a big impact on your bottom line. This is the size we chose based on our needs. Feel free to use it as a reference when designing your own system.
7,200 WATTS OF SOLAR POWER
By connecting 240w panels in series of 5, we could create high voltage arrays that charged well even in cloudy conditions. This also helped keep our wire size down as we had a fairly long run from the ground mount to the charge controllers (over 100’). Read more about this here.
28KWH LITHIUM BATTERY BANK
A key part of us savings tons of money were buying 280AH cells shipped directly from China. We knew the BMS would only have 16 cell inputs so we opted for 32 total batteries, grouping them in packs of 2. Read more about this here.
5,000 WATT 120V POWER INVERTER
We settled on a 5,000 Watt Quattro Inverter Charger from Victron. It runs 120V AC power, and surges to 10,000 watts which should be more than enough for us. The decision to go with Victron also tied into our charge controllers, BMS, the ability to monitor the system remotely, and manage all power systems on the property from one app. Read more about this here.
- Solar Panel Array & Ground Mount
- Building Lithium Battery Bank
- REC BMS
- Victron Color Control GX & 5000W Quattro Inverter
- Victron MPPT SmartSolar Charge Controllers
- Conduit, Wire, & Service Entrances
- Tools & Connectors
Solar Panel Array & Ground Mount
When considering your solar panels, don't forget that building a safe and secure ground mount to house them on will be expensive! Consider doing the opposite of us, and buying more expensive, higher wattage panels so your ground mount doesn't have to be so large.
A couple of notes:
- Some elements below are better sourced directly from your hardware store or industrial metal supply store, so no links.
- Also, watch out for delivery charges. We paid nearly $600 extra in delivery fees for the Schedule 40 Pipe and IronRidge components. If you have a flatbed trailer and can haul yourself it may be worth the trip.
We cover the full ground mount installation and solar panel wiring here if you're looking for more details.
|7200 W Solar Array - 240w Cracked Back x 30||$712.50|
|10 AWG PV Solar wire x 300'||$150.00|
|MC4 Connectors x 24||$40.00|
|4 String PV Combiner Box with Lightning Arrester x2||$132.00|
|Black 6 AWG Stranded THHN x 500'||$327.36|
|8' Grounding Rods + Lugs x 3||$45.00|
|21' Steel Grade A 3" Sch 40 Pipe x 8||$1,763.83|
|80lb Quickcrete x 236||$844.14|
|8x8x16 Cinder Blocks x 112||$178.08|
|IronRidge 17' Rail XR1000 x 12||$720.00|
|IronRidge UFO Module Clamp x 72||$140.40|
|IronRidge UFO Stopper Sleeve x 24||$6.72|
|IronRidge Grounding Lug x1||$3.93|
|IronRidge 3" Top Cap x 8||$290.64|
|IronRidge 3" Rail Connectors x 24||$241.20|
Building our own lithium battery bank via inexpensive cells shipped directly from China was an important part of us being able to get so much storage for so cheap.
As you can imagine, there are potential caveats to this, so make sure to read our in-depth breakdown of the purchasing process.
UPDATE: Now you can get the same cheap lithium cells delivered much faster from U.S. based warehouses.
And don't forget that you'll need to build your own battery box to house and compress the cells as well.
|3.2V 280AH REPT LiFePO4 cells x 32
|1/8" x 1.5" Copper Bus Bar x 16'||$170.00|
|4x8 3/4" Sheet Plywood||$40.00|
|Square Tube, Angle Iron, & Flat Bar Stock||$260.00|
|Allthread Rods, Nuts, Bolts, Washers, & Lock Washers||$120.00|
|Black 2/0 Welding Cable x 20'||$111.17|
|Red 2/0 Welding Cable x 20'||$115.02|
|2/0 AWG 3/8" Stud Lugs x 5||$11.81|
|Class T Fuse Housing||$43.59|
|Blue Sea 300A Class T Fuse||$50.40|
|Blue Sea Systems 300 Amp m-Series Battery Switch||$30.43|
Off-Grid Homestead Solar Wiring Guide
In the middle of pricing your own system, and just want to see how everything connects together? As part of our installation article, we created a very detailed replica of our wiring setup.
I know I'm a visual person, and sometimes I just need to see it all laid out no matter how many words there are to explain it.
If you'd like to download a vector PDF that you can zoom in on, grab a copy here:
I can’t overstate enough how important a BMS or Battery Management System is for lithium batteries. A good BMS should:
- Protect from Overvoltage & Undervoltage
- Protect from Temperature Extremes.
- Charge & Float Properly
- Balance the Cells
The BMS comes with multiple components, so make sure to check out the wiring guide and install process in the article.
|REC Q Series BMS 16S||$559.75|
|Current Sensing Shunt (200A)||$69.95|
|Precharge resistor delay (48V)||$85.45|
|REC LCD Touch Display|
|Cable for Victron VE.Can||$28.45|
Victron Color Control GX & 5000W Quattro Inverter
The other big decision for our install was what the hub or power center would run on. We chose Victron because of their great reputation for off-grid solutions, the ability to connect all the components to it, and the VRM Remote Management portal that lets us access our install from anywhere in the world.
|Victron Quattro 5000W 48V Pure Sine Wave Inverter Charger||$2,542.35|
|Victron VE.Direct cable x2||$37.40|
|Victron VE.Bus or Ethernet Cable||$24.00|
Victron SmartSolar MPPT Solar Charge Controllers
As part of our Victron system, we added multiple SmartSolar charge controllers because our panel array was so large. This will also allow us to add to the system if needed without replacing these units.
|Back 2 AWG Welding Cable 20'||$48.97|
Conduit, Wire, & Service Entrances
In addition to the solar panels, batteries, inverter, and charge controllers we had a lot of additional expenses related to long trenched conduit runs, service entrances, and more.
Like some other items in this cost breakdown, most either need to be sourced from your local hardware store - or can be found much cheaper than using the Amazon links below. Just keep that in mind.
|6/2 Direct Bury Wire x 175'||$400.00|
|8x8 PVC Junction Box||$34.00|
|1.5" Unistrut pipe clamps x 6||$23.00|
PVC Conduit 1.5" x 160'
PVC Conduit 1.25" x 100'
Tools & Connectors
We couldn't cover the install without mentioning the tools and connecters we needed to finish the job.
Most of these are pretty basic, but if you've never built your own cable before by crimping and heat shrinking a lug on, you may not have everything laying around.
|Century 120V Flux Cored Wire Feed Welder||$226.00|
Totaling it Up - How Much Did it Cost?
I know, I know - you're all like "Just tell me the total already!"
Fair enough :) Here's the breakdown:
|Solar Panel Array & Ground Mount||$5,666.30|
|Lithium Battery Bank||$4,779.53|
|Victron Color Control GX & 5000W Quattro Inverter||$3,327.58|
|MPPT Solar Charge Controllers||$1,900.49|
|Conduit, Wire & Service Entrances||$1,198.00|
|Tools & Connectors||$626.30|
Whew! Yeah that was a lot to get through. So all in all, we spent about $19,000 on our 7200W 28kWH 5000W off-grid solar power system. By sourcing our own components and building our own battery bank we were able to save 10's of thousands of dollars for this massive system that will power our homestead.
We hope this breakdown and installation recap help you build your own off-grid solar system!
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