What you’ll build

A PERMITTED, INSPECTED, signed-off 3.2kW standalone solar system on YOUR property. Eight 400W panels, one string, an off-grid inverter/charger, a 5kWh LiFePO4 battery, and a 120V outlet. Not connected to the grid. Not connected to the utility monopoly. STANDALONE — on your shed, garage, or workshop.

This is the REAL thing. Not a toy. Not a science project. A code-compliant, inspector-approved power plant that runs REAL loads, passes EVERY inspection, and tells the utility company you don’t need them! One permit. Two inspections. Signed off. DONE.

If you built the 200W starter system, you already know the basics. This is the UPGRADE — permits, AC output, full code compliance, grounding, labeling. Everything an inspector needs to see, done RIGHT. Power tools, a fridge, lights, your whole workshop — running on YOUR power!

What you can power

Daily generation (national averages, Sun Belt states): roughly 12.8 to 16 kWh EVERY DAY; northern states: 9.6 to 12.8 kWh EVERY DAY (3,200W x 3-5 peak sun hours x 0.80 derate). Use NREL PVWatts to calculate YOUR location. That’s real energy. From YOUR roof. For FREE.

Through your 120V outlet:

  • Power tools — circular saw, drill, router, grinder. YOUR tools, YOUR power!
  • Mini-fridge — cold drinks in the shop, runs 24/7 off the battery. ZERO from the grid.
  • Phone and laptop charging — indefinite. Never plugging into the monopoly for this again.
  • LED lighting — light up the workshop. No utility bill. NONE.
  • Battery chargers — tool batteries, e-bike, whatever YOU need
  • Small space heater — 1,500W heater eats most of your daily generation and drains the battery in about 3 hours. Doable with trade-offs.

One outlet is intentional — it’s the minimum the inspector needs to sign off a complete system. You can add more outlets later. Start with one, get it DONE, expand from there.

The permit process

This is paperwork. That’s it. The inspector WANTS you to pass. Show up prepared and you will.

Who can do this

YOU. The homeowner. Owner and occupant of the property. Most states have homeowner exemption laws allowing you to perform electrical work on property you own and occupy. Check your state’s homeowner exemption — it’s your legal right. No contractor license needed in most jurisdictions. YOUR property, YOUR work.

Where to go

Your local building department. Search “[your city] building permit electrical” to find the right office. File online or in person.

What to bring

  • Electrical permit application (filled out)
  • Site plan showing the structure on your property
  • Line diagram (panels -> DC disconnect -> inverter -> battery -> AC disconnect -> outlet)
  • Equipment spec sheets with UL listings
  • YOUR signature as the homeowner

Cost

A few hundred dollars for the permit. Contact your local building department for the exact fee.

The 180-day clock

Permit expires if you don’t start within 180 days or stop work for 180 days. Each inspection resets the clock. Don’t sit on it.

Inspections

TWO. That’s ALL.

  1. Rough-in: Wiring installed, not concealed. Inspector checks routing, sizing, grounding, workmanship.
  2. Final: Everything done. Inspector checks the ENTIRE system. Disconnects, labels, grounding, listings, protection, outlet.

Pass both and you’re DONE. Nobody comes back. Nobody sends you a bill.

System design

Panels and string configuration

8x 400W monocrystalline panels, series wired (single string).

Per-panel specs:

SpecValue
Open-circuit voltage (Voc)~41V
Short-circuit current (Isc)~13A
Maximum power voltage (Vmp)~34V
Maximum power current (Imp)~11.8A

String characteristics (8 panels in series):

ParameterCalculationResult
String Voc8 x 41V328V DC
Temperature-corrected max Voc (-15 C)328V x 1.14374V DC
String Vmp8 x 34V272V DC
String IscSame as one panel13A

Listing: UL 61730 or UL 1703. Every reputable manufacturer has this — Canadian Solar, REC, QCells, LONGi, JA Solar, Trina.

PRIORITIZE AMERICAN-MADE PANELS. Every dollar on Chinese panels FUNDS THE CCP. Check manufacturer filings for factory locations. American-assembled panels from American workers — that’s the patriot’s choice. The domestic manufacturing capacity is GROWING. If you can get American-made at a competitive price, there is NO reason to send your money overseas.

Why 400W: Sweet spot. Great output, manageable size (6.8’ x 3.4’, ~50 lbs), widely available. Single string of 8 gives a clean 272V to 374V window for your inverter.

Inverter selection

Off-grid inverter/charger. One unit: takes DC from your panels, charges the battery, outputs 120V AC to YOUR outlet.

Required specs:

RequirementSpec
MPPT voltage windowMust accept 272V to 374V DC
AC output120V single-phase
Continuous power3,000 to 3,500W
ListingUL 1741 — NO EXCEPTIONS

Reference products: EG4 6000XP, Victron MultiPlus/Quattro, Sol-Ark, Growatt SPF series. Research starting points. VERIFY the UL 1741 listing on YOUR specific model before you buy!

Mount inside the structure. Ventilation, clearance per manufacturer specs. Bond the enclosure to ground.

Battery

5kWh LiFePO4 (48V 100Ah server rack battery).

RequirementSpec
ChemistryLiFePO4 (Lithium Iron Phosphate)
Capacity5kWh (48V x 100Ah)
ListingUL 9540, UL 9540A, or UL 1973
CommunicationCAN bus or RS485 — CONFIRM inverter compatibility

Why LiFePO4: No hydrogen gas, built-in BMS, 3,000 to 6,000+ cycles, thermally stable. SAFEST lithium chemistry available!

Why 5kWh: Real overnight capacity. One unit, simple. Add another in parallel later when you want more. Start smart, grow as needed.

Reference products: SOK 48V 100Ah (UL 1973), EG4 LL series (UL listed), Victron Lithium Smart (UL listed). VERIFY listing and inverter compatibility. Check country of origin — know where YOUR money goes!

Installation: DC disconnect between battery and inverter. DC-rated overcurrent protection. Accessible for inspection. Labeled with voltage and chemistry. Standard ventilation is fine for LiFePO4. Secured against tipping.

Grounding and bonding

This is where MOST DIY systems FAIL. Every piece of metal that could get energized during a fault needs a low-impedance path to ground. This isn’t optional. This is what keeps people SAFE.

Equipment grounding:

  • Listed PV grounding lug (UL 2703) on EVERY panel frame — serrated contacts that bite through anodized coating. WEEB, IronRidge, Burndy, or Ilsco.
  • CONTINUOUS bare or green copper EGC daisy-chained through EVERY panel, to inverter ground terminal, to electrode.
  • EGC sizing: 10 AWG copper minimum (NEC 690.45 / Table 250.122).
  • Bond EVERY metallic enclosure: inverter, battery rack, junction boxes, conduit, disconnects.

Grounding electrode system:

  • TWO ground rods: 8-foot copper-clad steel, minimum 6 feet apart.
  • GEC: 6 AWG bare copper, listed acorn clamps.
  • Protect GEC from physical damage where exposed.
  • Standalone — no bond to house ground. YOUR shed has its OWN ground rods.

Bill of materials

EVERYTHING you need. Specs and listing requirements so YOU can source the best deal. No middleman. No markup.

Array

ComponentSpecificationListingApprox. Cost
400W Monocrystalline Panel (x8)Voc ~41V, Isc ~13AUL 61730$800-1,200
Z-Bracket Panel Mounts (8 panels)Universal roof mount—$60-120
PV Grounding Lugs (x8)Serrated contactUL 2703$16-40

DC Wiring

ComponentSpecificationListingApprox. Cost
10 AWG PV Wire, Red (100ft)USE-2, UV-rated, 600VUL$30-50
10 AWG PV Wire, Black (100ft)USE-2, UV-rated, 600VUL$30-50
600V DC Disconnect (30A)NEMA 3R, DC-ratedUL$40-80
EMT Conduit 3/4” (10ft x2+)Galvanized, exteriorUL$15-30

Inverter

ComponentSpecificationListingApprox. Cost
Off-Grid Inverter/Charger3,000-6,000W, MPPT 120-500V DC, 120VUL 1741$1,200-1,800

Battery

ComponentSpecificationListingApprox. Cost
48V 100Ah LiFePO4 Battery5kWh, server rack, CAN/RS485UL 9540 or UL 1973$1,500-2,500
DC Battery Fuse/BreakerDC-rated, per specsUL$20-40

AC Wiring

ComponentSpecificationListingApprox. Cost
12 AWG NM-B (25ft)AC branch, 20AUL$15-25
120V AC Disconnect (20A)Standard ACUL$15-30
20A GFCI Outlet (NEMA 5-20R)NEC 210.8(A)UL$15-25
Electrical Boxes + CoversStandardUL$10-20

Grounding

ComponentSpecificationListingApprox. Cost
6 AWG Bare Copper (25ft)GEC—$25-40
10 AWG Green/Bare Copper (50ft)EGC—$20-35
Ground Rods 8ft (x2)Copper-clad, 6ft apartUL$20-30
Acorn Clamps (x2)For 6 AWGUL$8-15

Labels

ComponentSpecificationApprox. Cost
PV Warning Labels (set)Pre-made, UV-resistant$15-30
Label MakerBrother P-Touch or similar$30-50

TOTAL: $3,900 to $6,100

But WAIT — the 30% federal ITC puts money BACK in YOUR pocket! A $5,000 system becomes $3,500. That’s $1,500 of YOUR tax dollars coming HOME. The government took your money — here’s how to claw some back. See Incentives for the FULL breakdown!

Buying strategy: Order ALL 8 panels in one shipment — freight is the big cost, and matched panels from the same batch have consistent specs. VERIFY UL listings before ordering. Known manufacturers for inverter and battery — that’s where the money is. Buy extra wire and fuses.

Wiring topology

Full connection map. Panels to outlet. Every component, every connection:

Panels (8x series) -> PV Wire (10 AWG) -> DC Disconnect (600V, 30A) -> Inverter MPPT -> Battery OCPD -> Battery -> Inverter AC Out -> AC Disconnect (120V, 20A) -> GFCI Outlet (NEMA 5-20R)

Conductor specs

CircuitWireGaugeNotes
DC sourcePV Wire / USE-210 AWG minUV-rated, 600V, exterior
Interior DCTHWN-2 in conduit10 AWG minTransition at junction box
AC branchNM-B12 AWG20A, interior
Battery to inverterPer manufacturerPer specShort, heavy gauge
EGCBare/green copper10 AWG minCONTINUOUS, all panels
GECBare copper6 AWGProtected from damage

Wire types

  • Exterior: PV Wire or USE-2 ONLY. UV-resistant, 600V rated.
  • Exterior conduit: EMT for exposed runs.
  • Interior DC: THWN-2 in conduit. Transition at listed junction box.
  • Interior AC: NM-B, stapled per NEC (12” from boxes, 4.5’ intervals).

GFCI

REQUIRED by NEC 210.8(A) for accessory buildings. GFCI receptacle or GFCI breaker. Costs $15. Common inspection failure. Don’t be the patriot who fails over a $15 outlet!

Labeling

THIS is where DIY systems fail inspection more than ANYTHING else. It’s easy. It’s cheap. And it’s the difference between a PASS and coming back next week!

Required labels

DC disconnect:

  • “SOLAR PV SYSTEM DISCONNECT”
  • Maximum DC voltage: 374V DC
  • Maximum DC current: 13A

AC disconnect:

  • “SOLAR PV AC DISCONNECT”
  • Rated voltage: 120V AC

Conduits/raceways:

  • “SOLAR PV CIRCUIT” or “PHOTOVOLTAIC POWER SOURCE”
  • At EVERY accessible point, junction box, and building entry

Inverter:

  • Manufacturer’s listing label VISIBLE and INTACT

Battery/ESS:

  • “ENERGY STORAGE SYSTEM”
  • Voltage: 48V DC
  • Chemistry: “LITHIUM IRON PHOSPHATE — LiFePO4”

Power source directory (NEC 710.10):

  • Permanent plaque at main disconnect: source type, disconnect locations, voltages

Warning labels:

  • “WARNING: ELECTRIC SHOCK HAZARD — DO NOT TOUCH TERMINALS. TERMINALS ON BOTH LINE AND LOAD SIDES MAY BE ENERGIZED IN THE OPEN POSITION.”
  • At the array: “WARNING: SOLAR PV — ENERGIZED IN DAYLIGHT”

Durable. Weather-resistant. UV-resistant. Legible. Per NEC 110.21(B).

Step-by-step build

Fifteen steps. In order. Take your time. Getting this RIGHT the first time is how patriots build things!

1. Prep workspace. Clear the area. Post the line diagram. ALL materials and tools laid out. Verify the FULL BOM is on site.

2. Pull permit. Application, site plan, line diagram, spec sheets. Pay the fee. Post the permit. YOUR right as a property owner.

3. Mount panels (two-person job). 50 lbs each, awkward in wind. Overcast days are easier on you and produce less voltage. Verify layout matches site plan.

4. Install grounding lugs on EVERY panel frame. One UL 2703 lug per panel. Serrated contact biting through anodization. EVERY. PANEL.

5. Run PV wire from array to equipment location. 10 AWG through EMT conduit. Service loops at both ends.

6. Drive ground rods. Two 8-foot rods, 6 feet apart. 6 AWG copper, listed acorn clamps.

7. Install inverter and battery. Inverter on wall. Battery in rack. Ventilation, access, room to work.

8. Install DC disconnect. 600V DC-rated. Between array and inverter.

9. Wire DC side (disconnect OFF). PV wire to disconnect input. Disconnect output to inverter MPPT. EGC from panel lugs through EVERY component to ground rods.

10. Wire battery (don’t connect yet). Battery OCPD installed. Cables to inverter. Breaker stays OPEN.

11. Wire AC side. Inverter -> AC disconnect (20A) -> 12 AWG NM-B -> GFCI outlet. Stapled per code.

12. Install ALL labels. Every. Single. One. Right now. Before the inspector shows up.

13. Call for rough-in inspection. Permit posted. Spec sheets ready. Line diagram visible.

14. After rough-in passes: energize and test. Battery FIRST. Verify inverter sees it. DC disconnect ON. Check MPPT voltage. Check AC at outlet. Test GFCI.

15. Call for final inspection. Everything complete. Everything labeled. Everything grounded. Everything listed. Pass this — and you’re DONE!

Inspection checklist

Run through this YOURSELF before the inspector shows up!

Documentation

  • Permit posted on site
  • Equipment spec sheets available
  • Line diagram available
  • Panel listing (UL 61730 / UL 1703) visible
  • Inverter listing (UL 1741) visible
  • Battery listing (UL 9540 / UL 1973) visible

Array

  • Panels securely mounted
  • Grounding lug at EACH panel — listed, penetrating anodization
  • EGC CONTINUOUS through all panels
  • MC4 connections seated and locked
  • PV wire / USE-2 for exterior
  • Conductors protected from damage

Disconnects

  • DC disconnect: installed, accessible, 600V DC, 30A
  • AC disconnect: installed, accessible, 120V, 20A
  • Both operational

Wiring

  • Correct gauge (10 AWG min DC, 12 AWG for 20A AC)
  • Correct wire types
  • All connections in listed enclosures
  • Conduit fill within limits
  • NM-B properly stapled

Grounding

  • EGC continuous from array to electrode
  • Ground rods driven 8 feet, listed clamps
  • GEC 6 AWG minimum
  • GEC protected from damage
  • ALL metallic enclosures bonded

Overcurrent Protection

  • DC source circuit protection
  • Battery circuit protection
  • AC breaker matches wire gauge

Outlet

  • GFCI protection
  • Proper box and cover plate
  • Correct wiring

Labels

  • DC disconnect labeled
  • AC disconnect labeled
  • PV conduits labeled
  • Battery/ESS labeled
  • Power source directory posted
  • Warning labels at energized points

Safety

  • Panels are ALWAYS live in daylight. No off switch on a solar panel. Cover them while working. ALL panel wiring is energized during the day!
  • Fuse and protect EVERY circuit. DC, battery, AC — every junction gets overcurrent protection. Sized correctly!
  • Listed components ONLY. UL markings are required for inspection AND insurance. No exceptions. EVER.
  • Torque to spec. Loose connections = heat. Heat = fire. Use a torque wrench. EVERY time.
  • UV-rated wire outdoors. Regular Romex fails in sunlight. PV wire doesn’t. Don’t cut corners.
  • Inverter and battery INDOORS with ventilation. Protected, accessible, proper airflow.
  • If something’s wrong — STOP. Unexpected readings, heat, smells — disconnect and figure it out. See About for a professional assessment.

What’s next

You have a permitted, inspected, signed-off system. LEGAL. SAFE. YOURS. Zero from the monopoly! 🇺🇸

This is a foundation. Everything from here is expansion, not starting over:

  • More battery: Another 48V 100Ah in parallel. DOUBLE the overnight storage!
  • More outlets or subpanel: More circuits from the inverter output.
  • Ground mount expansion: More panels, same principles.

The 30% federal ITC puts YOUR tax dollars back in YOUR pocket. See Incentives for the math!

If this feels like a big step, start with the 200W system. One afternoon, one panel, and you’ll KNOW how solar works before going bigger.

For deeper technical understanding: batteries, inverters, string design, wiring and safety.

They DON’T want you reading this page. That’s how you KNOW it’s important. TAKE BACK YOUR POWER! Get your FREE energy audit! 🇺🇸

DATA SOURCED FROM: NEC 2023 (Articles 210.8, 250, 480, 690, 706, 710), NEC 690.12 Exception No. 2 (rapid shutdown exemption), NEC 690.7 Table 690.7(A) (temperature correction), NEC 690.8 (circuit sizing), NEC 690.45 / Table 250.122 (EGC sizing), NEC 250.53 (grounding electrodes), NREL PVWatts (production estimates), state homeowner exemption laws (check your state), manufacturer published specifications (component data, listing certifications). We’re using THEIR data against them. EVERY stat sourced. EVERY claim verified.